以前的spring相当于现在的springframework
SpringBoot的底层是SpringFramework
SpringBoot有接口的默认实现
SpringBoot的优点:
SpringBoot是整合Spring技术栈的一站式框架
SpringBoot是简化Spring技术栈的快速开发脚手架
缺点:
封装太深,内部原理复杂,不容易精通
微服务的具体概念
微服务是一种架构风格
一个应用拆分为一组小型服务
每个服务运行在自己的进程内,也就是可独立部署和升级
服务之间使用轻量级HTTP交互
服务围绕业务功能拆分
可以由全自动部署机制独立部署
去中心化,服务自治。服务可以使用不同的语言、不同的存储技术
远程调用
服务发现
负载均衡
服务容错
配置管理
服务监控
链路追踪
日志管理
云原生
原生应用如何上云。 Cloud Native
配置Maven的setting.xml
更换maven源和jdk版本:
<profiles>
<profile>
<id>jdk-1.8id>
<activation>
<activeByDefault>trueactiveByDefault>
<jdk>1.8jdk>
activation>
<properties>
<maven.compiler.source>1.8maven.compiler.source>
<maven.compiler.target>1.8maven.compiler.target>
<maven.compiler.compilerVersion>1.8maven.compiler.compilerVersion>
properties>
profile>
profiles>
<mirrors>
<mirror>
<id>nexus-aliyunid>
<mirrorOf>centralmirrorOf>
<name>Nexus aliyunname>
<url>http://maven.aliyun.com/nexus/content/groups/publicurl>
mirror>
mirrors>
浏览器发送一个/hello请求,响应hello,springBoot2
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<groupId>com.tjkgroupId>
<artifactId>HelloWorldartifactId>
<version>1.0-SNAPSHOTversion>
<parent>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-parentartifactId>
<version>2.3.4.RELEASEversion>
parent>
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
dependencies>
project>
/**
* 表明这是一个springBoot的应用
* 表明这是主程序类
*/
@SpringBootApplication
public class MainApplication {
public static void main(String[] args) {
SpringApplication.run(MainApplication.class,args);
}
}
@SpringBootApplication:
表明这是一个springBoot的应用 * 表明这是主程序类,可以用做启动类
@RestController //(@ResponseBody=@ResponseBody + @Controller)
public class HelloController {
@RequestMapping("/hello")
public String handle(){
return "helloSpringBoot 2";
}
}
<build>
<plugins>
<plugin>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-maven-pluginartifactId>
plugin>
plugins>
build>
注意:
取消cmd的快速编辑模式(防止在运行的时候,卡住)
SpringBoot引入一个已经创建好的一个官方父项目,这个项目中引入的所有jar包全部都会导入到你所构造的项目当中,里面所有的jar包版本是已经规定好的,如果你需要修改,那么必须按照如下操作:
<parent>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-parentartifactId>
<version>2.3.4.RELEASEversion>
parent>
//他的父项目
<parent>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-dependenciesartifactId>
<version>2.3.4.RELEASEversion>
parent>
几乎声明了所有开发中常用的以来版本号
如果想要使用自己想要的jar包版本号
可以在pom.xml中进行声明:
<properties>
<mysql.version>版本号mysql.version>
properties>
1、见到很多 spring-boot-starter-* : *就某种场景
2、只要引入starter,这个场景的所有常规需要的依赖我们都自动引入
3、SpringBoot所有支持的场景
starter文档
4、见到的 *-spring-boot-starter: 第三方为我们提供的简化开发的场景启动器。
5、所有场景启动器最底层的依赖
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starterartifactId>
<version>2.3.4.RELEASEversion>
<scope>compilescope>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-tomcatartifactId>
<version>2.3.4.RELEASEversion>
<scope>compilescope>
dependency>
@SpringBootApplication(scanBasePackages="com.tjk") 或者@ComponentScan 指定扫描路径
@SpringBootApplication
等同于
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan("com.tjk.boot")
/**
* 配置类里面使用@Bean标注在方法上给容器注册组件 默认也是单实例的
* 配置类也是组件
* proxyBeanMethods:代理bean的方法
* proxyBeanMethods = true:Full
* proxyBeanMethods = false:
* Lite 组建依赖 如果是false 每次调用容器中的组件就会创建一个新的实例
*/
@Configuration(proxyBeanMethods = true) //告诉springboot这是一个配置类 === 配置文件
public class MyConfig {
/**
* 外部无论对配置类的这个组件注册方法调用多少次,获取的都是之前注册容器中的单实例对象
* @return
*/
@Bean //给容器中添加组件 以方法名作为组件的id 返回类型作为组件的类型 返回数据就是组件在容器中的实例
public Stu stu01(){
return new Stu("tjk","男",18);
}
@Bean
public Animal animal01(){
return new Animal("xiaobai ");
}
}
/**
* 表明这是一个springBoot的应用
* 表明这是主程序类
*/
@SpringBootApplication
public class MainApplication {
public static void main(String[] args) {
/**
1. 返回ioc容器
2. 查看容器里面的所有组件
*/
ConfigurableApplicationContext run =SpringApplication.run(MainApplication.class,args);
String[] names= run.getBeanDefinitionNames();
/* for (String name : names) {
System.out.println(name);
}*/
//从容器中获取组件
Stu stu01=run.getBean("stu01", Stu.class);
Stu stu02=run.getBean("stu01", Stu.class);
System.out.println(stu01==stu02);
/**
* 如果@Configuration(proxyBeanMethods = true)代理对象调用方法,SpringBoot总会检查这个组件 是否存在容器中
* 保持组件单实例
*/
}
@ConditionalOnBean(name = "tom2"):
配置类中有名字为tom2的装配类时,才会执行下面的方法@ConditionalOnMissingBean(name=“tom2”):
配置类中没有名字为tom2的装配类时才会进行下面操作 <bean id="haha" class="com.tjk.mainApplication.bean.Stu">
<property name="name" value="tjk">property>
<property name="age" value="18">property>
<property name="sex" value="男">property>
bean>
<bean id="hehe" class="com.tjk.mainApplication.bean.Animal">
<property name="name" value="小白">property>
bean>
boolean haha = run.containsBean("haha");
System.out.println("容器中haha:"+haha);
boolean hehe = run.containsBean("hehe");
System.out.println("容器中hehe:"+hehe);
如何使用Java读取到properties文件中的内容,并且把它封装到JavaBean中,以供随时使用;
public class getProperties {
public static void main(String[] args) throws FileNotFoundException, IOException {
Properties pps = new Properties()
pps.load(new FileInputStream("a.properties"));
Enumeration enum1 = pps.propertyNames();//得到配置文件的名字
while(enum1.hasMoreElements()) {
String strKey = (String) enum1.nextElement();
String strValue = pps.getProperty(strKey);
System.out.println(strKey + "=" + strValue); //封装到JavaBean
}
}
}
SpringBoot的方法:
@ConfigurationProperties(prefix = "mycar")+@component
@component (把普通pojo实例化到spring容器中,相当于配置文件中的
)
mycar.brand=BYD
mycar.price=100000
@Autowired
Car car;
@RequestMapping("/car")
public Car car(){
return car;
}
2. @EnableConfigurationProperties + @ConfigurationProperties
这个需要在需要注入的类和配置类上进行操作
@EnableConfigurationProperties(Car.class)
/*
1. 开启car的属性配置功能
2. 把这个car自动注册到容器中
*/
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(
excludeFilters = {@Filter(
type = FilterType.CUSTOM,
classes = {TypeExcludeFilter.class}
), @Filter(
type = FilterType.CUSTOM,
classes = {AutoConfigurationExcludeFilter.class}
)}
)
public @interface SpringBootApplication
@AutoConfigurationPackage
@Import({AutoConfigurationImportSelector.class})
@Import({Registrar.class})//给容器导入一个组件
public @interface AutoConfigurationPackage {
利用Registrar给容器中导入一系列组件
将指定的一个包下面所有组件导入进来即默认是MianApplication所在包下
1.利用getAutoConfigurationEntry(annotationMetadata)给容器中批量导入一些组件
2、调用List<String> configurations = getCandidateConfigurations(annotationMetadata, attributes)获取到所有需要导入到容器中的配置类
3、利用工厂加载 Map<String, List<String>> loadSpringFactories(@Nullable ClassLoader classLoader);得到所有的组件
4、从META-INF/spring.factories位置来加载一个文件。
默认扫描我们当前系统里面所有META-INF/spring.factories位置的文件
spring-boot-autoconfigure-2.3.4.RELEASE.jar包里面也有META-INF/spring.factories
文件中写死了Spring-Boot启动就给容器中加载的所有配置类
spring-boot-autoconfigure-2.3.4.RELEASE.jar META-INF/spring.factories
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\
org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\
org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration,\
org.springframework.boot.autoconfigure.batch.BatchAutoConfiguration,\
org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration,\
org.springframework.boot.autoconfigure.cassandra.CassandraAutoConfiguration,\
org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration,\
org.springframework.boot.autoconfigure.context.LifecycleAutoConfiguration,\
org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration,\
org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration,\
org.springframework.boot.autoconfigure.dao.PersistenceExceptionTranslationAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.cassandra.CassandraRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.couchbase.CouchbaseRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ReactiveElasticsearchRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.elasticsearch.ReactiveElasticsearchRestClientAutoConfiguration,\
org.springframework.boot.autoconfigure.data.jdbc.JdbcRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.solr.SolrRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.r2dbc.R2dbcDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.r2dbc.R2dbcRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.r2dbc.R2dbcTransactionManagerAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisReactiveAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration,\
org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchRestClientAutoConfiguration,\
org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration,\
org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration,\
org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration,\
org.springframework.boot.autoconfigure.h2.H2ConsoleAutoConfiguration,\
org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration,\
org.springframework.boot.autoconfigure.hazelcast.HazelcastAutoConfiguration,\
org.springframework.boot.autoconfigure.hazelcast.HazelcastJpaDependencyAutoConfiguration,\
org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration,\
org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration,\
org.springframework.boot.autoconfigure.influx.InfluxDbAutoConfiguration,\
org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration,\
org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration,\
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.XADataSourceAutoConfiguration,\
org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.JmsAutoConfiguration,\
org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.JndiConnectionFactoryAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.activemq.ActiveMQAutoConfiguration,\
org.springframework.boot.autoconfigure.jms.artemis.ArtemisAutoConfiguration,\
org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration,\
org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration,\
org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration,\
org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration,\
org.springframework.boot.autoconfigure.availability.ApplicationAvailabilityAutoConfiguration,\
org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration,\
org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration,\
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration,\
org.springframework.boot.autoconfigure.mail.MailSenderAutoConfiguration,\
org.springframework.boot.autoconfigure.mail.MailSenderValidatorAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration,\
org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration,\
org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration,\
org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration,\
org.springframework.boot.autoconfigure.quartz.QuartzAutoConfiguration,\
org.springframework.boot.autoconfigure.r2dbc.R2dbcAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketMessagingAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketRequesterAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketServerAutoConfiguration,\
org.springframework.boot.autoconfigure.rsocket.RSocketStrategiesAutoConfiguration,\
org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.servlet.UserDetailsServiceAutoConfiguration,\
org.springframework.boot.autoconfigure.security.servlet.SecurityFilterAutoConfiguration,\
org.springframework.boot.autoconfigure.security.reactive.ReactiveSecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.reactive.ReactiveUserDetailsServiceAutoConfiguration,\
org.springframework.boot.autoconfigure.security.rsocket.RSocketSecurityAutoConfiguration,\
org.springframework.boot.autoconfigure.security.saml2.Saml2RelyingPartyAutoConfiguration,\
org.springframework.boot.autoconfigure.sendgrid.SendGridAutoConfiguration,\
org.springframework.boot.autoconfigure.session.SessionAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.client.reactive.ReactiveOAuth2ClientAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.resource.servlet.OAuth2ResourceServerAutoConfiguration,\
org.springframework.boot.autoconfigure.security.oauth2.resource.reactive.ReactiveOAuth2ResourceServerAutoConfiguration,\
org.springframework.boot.autoconfigure.solr.SolrAutoConfiguration,\
org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration,\
org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration,\
org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration,\
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration,\
org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfiguration,\
org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration,\
org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration,\
org.springframework.boot.autoconfigure.web.embedded.EmbeddedWebServerFactoryCustomizerAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.HttpHandlerAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.ReactiveWebServerFactoryAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.error.ErrorWebFluxAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.function.client.ClientHttpConnectorAutoConfiguration,\
org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.HttpEncodingAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.MultipartAutoConfiguration,\
org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.reactive.WebSocketReactiveAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.servlet.WebSocketServletAutoConfiguration,\
org.springframework.boot.autoconfigure.websocket.servlet.WebSocketMessagingAutoConfiguration,\
org.springframework.boot.autoconfigure.webservices.WebServicesAutoConfiguration,\
org.springframework.boot.autoconfigure.webservices.client.WebServiceTemplateAutoConfiguration
SpringBoot先默认加载所有的配置项,在进行筛选,将需求的加载项进行加载
xxxxAutoConfiguration
@Conditional
),最终会按需配置。 @Bean
@ConditionalOnBean(MultipartResolver.class) //容器中有这个类型组件
@ConditionalOnMissingBean(name = DispatcherServlet.MULTIPART_RESOLVER_BEAN_NAME) //容器中没有这个名字 multipartResolver 的组件
public MultipartResolver multipartResolver(MultipartResolver resolver) {
//给@Bean标注的方法传入了对象参数,这个参数的值就会从容器中找。
//SpringMVC multipartResolver。防止有些用户配置的文件上传解析器不符合规范
// Detect if the user has created a MultipartResolver but named it incorrectly
return resolver;
}
上面的函数相当于是 用户配置了文件上传解析器,但是没有按照官方的默认名字,然后就会经过这个函数返回给程序相应的官方解析器的名字
SpringBoot默认会在底层配好所有的组件。但是如果用户自己配置了以用户的优先
@Bean
@ConditionalOnMissingBean
public CharacterEncodingFilter characterEncodingFilter() {
}
总结:
• SpringBoot先加载所有的自动配置 xxxxxAutoConfiguration
• 每个自动配置类按照条件进行生效,默认都会绑定配置文件指定的值。xxxxProperties里面拿。xxxProperties和配置文件进行了绑定
• 生效的配置类就会给容器中装配很多组件
• 只要容器中有这些组件,相当于这些功能就有了
• 定制化配置
简化javaBean的开发
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
dependency>
@NoArgsConstructor//无参构造器
@AllArgsConstructor//有参构造器
@ToString//toString方法
@Data//get set方法 equals hashcode toString方法
public class Stu {
private String name;
private String sex;
private Integer age;
private Animal animal;
}
@NoArgsConstructor//无参构造器
@AllArgsConstructor//有参构造器
@ToString//toString方法
@Data//get set方法
@EqualsAndHashCode equals hashcode
@Slf4j
public ceshi(){
public int shishi(){
log.info(“启动了呢”);
}
}
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-devtoolsartifactId>
<optional>trueoptional>
dependency>
更改代码的任意部分,只需要按ctrl+f9就可进行热部署
但是上面的是进行重启
官方有需要付费的JRebel插件,是动态更新更新了的部分
Spring Boot provides auto-configuration for Spring MVC that works well with most applications.(大多场景我们都无需自定义配置)
The auto-configuration adds the following features on top of Spring’s defaults:
• Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.
• 内容协商视图解析器和BeanName视图解析器
• Support for serving static resources, including support for WebJars (covered later in this document)).
• 静态资源(包括webjars)
• Automatic registration of Converter, GenericConverter, and Formatter beans.
• 自动注册 Converter,GenericConverter,Formatter
• Support for HttpMessageConverters (covered later in this document).
• 支持 HttpMessageConverters (后来我们配合内容协商理解原理)
• Automatic registration of MessageCodesResolver (covered later in this document).
• 自动注册 MessageCodesResolver (国际化用)
• Static index.html support.
• 静态index.html 页支持
• Custom Favicon support (covered later in this document).
• 自定义 Favicon
• Automatic use of a ConfigurableWebBindingInitializer bean (covered later in this document).
• 自动使用 ConfigurableWebBindingInitializer ,(DataBinder负责将请求数据绑定到JavaBean上)
If you want to keep those Spring Boot MVC customizations and make more MVC customizations (interceptors, formatters, view controllers, and other features), you can add your own @Configuration class of type WebMvcConfigurer but without @EnableWebMvc.
不用@EnableWebMvc注解。使用 @Configuration + WebMvcConfigurer 自定义规则
If you want to provide custom instances of RequestMappingHandlerMapping, RequestMappingHandlerAdapter, or ExceptionHandlerExceptionResolver, and still keep the Spring Boot MVC customizations, you can declare a bean of type WebMvcRegistrations and use it to provide custom instances of those components.
声明 WebMvcRegistrations 改变默认底层组件
If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with @EnableWebMvc, or alternatively add your own @Configuration-annotated DelegatingWebMvcConfiguration as described in the Javadoc of @EnableWebMvc.
使用 @EnableWebMvc+@Configuration+DelegatingWebMvcConfiguration 全面接管SpringMVC
#浏览器进行访问的时候必须要加的前缀 默认是没有的
spring:
mvc:
static-path-pattern: /res/**
#标注 哪个文件夹是生效的静态资源访问路径
#默认是上面的所有都生效
resources:
static-locations: [classpath:/haha/]
jquery的jar包
<dependency>
<groupId>org.webjarsgroupId>
<artifactId>jqueryartifactId>
<version>3.5.1version>
dependency>
spring:
# mvc:
# static-path-pattern: /res/** 这个会导致welcome page功能失效
resources:
static-locations: [classpath:/haha/]
将favicon.ico资源放在静态资源根目录下即可 可以起到每次访问的时候网页上的小图标
但是配置默认访问路劲会引起失效
spring:
# mvc:
# static-path-pattern: /res/** 这个会导致 Favicon 功能失效
@Configuration(proxyBeanMethods = false)
@ConditionalOnWebApplication(type = Type.SERVLET)
@ConditionalOnClass({ Servlet.class, DispatcherServlet.class, WebMvcConfigurer.class })
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
@AutoConfigureAfter({ DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class,
ValidationAutoConfiguration.class })
public class WebMvcAutoConfiguration {}
@Configuration(proxyBeanMethods = false)
@Import(EnableWebMvcConfiguration.class)
@EnableConfigurationProperties({ WebMvcProperties.class,
org.springframework.boot.autoconfigure.web.ResourceProperties.class, WebProperties.class })
@Order(0)
public static class WebMvcAutoConfigurationAdapter implements WebMvcConfigurer {}
//有参构造器所有参数的值,都会从该容器中确定
//ResourceProperties resourceProperties;获取和spring.resources绑定的所有的值的对象
//WebMvcProperties mvcProperties 获取和spring.mvc绑定的所有的值的对象
//ListableBeanFactory beanFactory Spring的beanFactory
//HttpMessageConverters 找到所有的HttpMessageConverters
//ResourceHandlerRegistrationCustomizer 找到 资源处理器的自定义器。=========
//DispatcherServletPath
//ServletRegistrationBean 给应用注册Servlet、Filter....
public WebMvcAutoConfigurationAdapter(WebProperties webProperties, WebMvcProperties mvcProperties,
ListableBeanFactory beanFactory, ObjectProvider<HttpMessageConverters> messageConvertersProvider,
ObjectProvider<ResourceHandlerRegistrationCustomizer> resourceHandlerRegistrationCustomizerProvider,
ObjectProvider<DispatcherServletPath> dispatcherServletPath,
ObjectProvider<ServletRegistrationBean<?>> servletRegistrations) {
this.mvcProperties = mvcProperties;
this.beanFactory = beanFactory;
this.messageConvertersProvider = messageConvertersProvider;
this.resourceHandlerRegistrationCustomizer = resourceHandlerRegistrationCustomizerProvider.getIfAvailable();
this.dispatcherServletPath = dispatcherServletPath;
this.servletRegistrations = servletRegistrations;
this.mvcProperties.checkConfiguration();
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
if (!this.resourceProperties.isAddMappings()) {
logger.debug("Default resource handling disabled");
return;
}
Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();
//webjars的规则
if (!registry.hasMappingForPattern("/webjars/**")) {
customizeResourceHandlerRegistration(registry.addResourceHandler("/webjars/**")
.addResourceLocations("classpath:/META-INF/resources/webjars/")
.setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
}
//
String staticPathPattern = this.mvcProperties.getStaticPathPattern();
if (!registry.hasMappingForPattern(staticPathPattern)) {
customizeResourceHandlerRegistration(registry.addResourceHandler(staticPathPattern)
.addResourceLocations(getResourceLocations(this.resourceProperties.getStaticLocations()))
.setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
}
}
spring:
# mvc:
# static-path-pattern: /res/**
resources:
add-mappings: false 禁用所有静态资源规则
@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties {
private static final String[] CLASSPATH_RESOURCE_LOCATIONS = { "classpath:/META-INF/resources/",
"classpath:/resources/", "classpath:/static/", "classpath:/public/" };
/**
* Locations of static resources. Defaults to classpath:[/META-INF/resources/,
* /resources/, /static/, /public/].
*/
private String[] staticLocations = CLASSPATH_RESOURCE_LOCATIONS;
HandlerMapping:处理器映射。保存了每一个Handler能处理哪些请求。
@Bean
public WelcomePageHandlerMapping welcomePageHandlerMapping(ApplicationContext applicationContext,
FormattingConversionService mvcConversionService, ResourceUrlProvider mvcResourceUrlProvider) {
WelcomePageHandlerMapping welcomePageHandlerMapping = new WelcomePageHandlerMapping(
new TemplateAvailabilityProviders(applicationContext), applicationContext, getWelcomePage(),
this.mvcProperties.getStaticPathPattern());
welcomePageHandlerMapping.setInterceptors(getInterceptors(mvcConversionService, mvcResourceUrlProvider));
welcomePageHandlerMapping.setCorsConfigurations(getCorsConfigurations());
return welcomePageHandlerMapping;
}
WelcomePageHandlerMapping(TemplateAvailabilityProviders templateAvailabilityProviders,
ApplicationContext applicationContext, Optional<Resource> welcomePage, String staticPathPattern) {
if (welcomePage.isPresent() && "/**".equals(staticPathPattern)) {
//要用欢迎页功能,必须是/**
logger.info("Adding welcome page: " + welcomePage.get());
setRootViewName("forward:index.html");
}
else if (welcomeTemplateExists(templateAvailabilityProviders, applicationContext)) {
// 调用Controller /index
logger.info("Adding welcome page template: index");
setRootViewName("index");
}
}
浏览器会发送 /favicon.ico请求获取到图标,整个session期间不再获取
@xxxMapping;
以前: | /getUser 获取用户 /deleteUser 删除用户 /editUser 修改用户 /saveUser 保存用户 |
现在: | /user GET-获取用户 DELETE-删除用户 PUT-修改用户 POST-保存用户 |
核心Filter; | HiddenHttpMethodFilter |
用法: | 表单method=post,隐藏域 _method=put |
SpringBoot中手动开启
• 扩展:如何把_method 这个名字换成我们自己喜欢的。
@RequestMapping(value = "/user",method = RequestMethod.GET)
public String getUser(){
return "GET-张三";
}
@RequestMapping(value = "/user",method = RequestMethod.POST)
public String saveUser(){
return "POST-张三";
}
@RequestMapping(value = "/user",method = RequestMethod.PUT)
public String putUser(){
return "PUT-张三";
}
@RequestMapping(value = "/user",method = RequestMethod.DELETE)
public String deleteUser(){
return "DELETE-张三";
}
@Bean @ConditionalOnMissingBean(HiddenHttpMethodFilter.class)
@ConditionalOnProperty(prefix = "spring.mvc.hiddenmethod.filter", name = "enabled", matchIfMissing = false)
public OrderedHiddenHttpMethodFilter hiddenHttpMethodFilter() {
return new OrderedHiddenHttpMethodFilter();
}
//自定义filter
@Bean
public HiddenHttpMethodFilter hiddenHttpMethodFilter(){
HiddenHttpMethodFilter methodFilter = new HiddenHttpMethodFilter();
methodFilter.setMethodParam("_m");
return methodFilter;
}
#是配置rest风格
spring:
mvc:
hiddenmethod:
filter:
enabled: true
Rest原理(表单提交要使用REST的时候)
• 表单提交会带上_method=PUT
• 请求过来被HiddenHttpMethodFilter拦截
• 请求是否正常,并且是POST
• 获取到_method的值。
• 兼容以下请求;PUT.DELETE.PATCH
• 原生request(post),包装模式requesWrapper重写了getMethod方法,返回的是传入的值。
• 过滤器链放行的时候用wrapper。以后的方法调用getMethod是调用requesWrapper的。
测试rest风格
需要首先开启rest风格的开关
然后界面上需要一个_method的参数 method可以写post
测试REST风格;
<form action="/user" method="get">
<input value="REST-GET 提交" type="submit"/>
form>
<form action="/user" method="post">
<input value="REST-POST 提交" type="submit"/>
form>
<form action="/user" method="post">
<input name="_method" type="hidden" value="delete"/>
<input name="_m" type="hidden" value="delete"/>
<input value="REST-DELETE 提交" type="submit"/>
form>
<form action="/user" method="post">
<input name="_method" type="hidden" value="PUT"/>
<input value="REST-PUT 提交" type="submit"/>
form>
Rest使用客户端工具,
• 如PostMan直接发送Put、delete等方式请求,无需Filter。
@Configuration(proxyBeanMethods = false)
public class MyConfig {
@Bean
public HiddenHttpMethodFilter hiddenHttpMethodFilter(){
HiddenHttpMethodFilter hiddenHttpMethodFilter= new HiddenHttpMethodFilter();
hiddenHttpMethodFilter.setMethodParam("_m");
return hiddenHttpMethodFilter;
}
}
首先传入原生的request 然后进行包装
SpringMVC功能分析都从 org.springframework.web.servlet.DispatcherServlet-》doDispatch()
protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
HttpServletRequest processedRequest = request;
HandlerExecutionChain mappedHandler = null;
boolean multipartRequestParsed = false;
WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
try {
ModelAndView mv = null;
Exception dispatchException = null;
try {
processedRequest = checkMultipart(request);
multipartRequestParsed = (processedRequest != request);
// 找到当前请求使用哪个Handler(Controller的方法)处理
mappedHandler = getHandler(processedRequest);
//HandlerMapping:处理器映射。/xxx->>xxxx
所有的请求映射都在HandlerMapping中。
• SpringBoot自动配置欢迎页的 WelcomePageHandlerMapping 。访问 /能访问到index.html;
• SpringBoot自动配置了默认 的 RequestMappingHandlerMapping
• 请求进来,挨个尝试所有的HandlerMapping看是否有请求信息。
• 如果有就找到这个请求对应的handler
• 如果没有就是下一个 HandlerMapping
• 我们需要一些自定义的映射处理,我们也可以自己给容器中放HandlerMapping。自定义 HandlerMapping
protected HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
if (this.handlerMappings != null) {
for (HandlerMapping mapping : this.handlerMappings) {
HandlerExecutionChain handler = mapping.getHandler(request);
if (handler != null) {
return handler;
}
}
}
return null;
}
@PathVariable | (路径变量) |
@RequestHeader | (获取请求头) |
@RequestParam | (获取请求参数) |
@CookieValue | (获取cookie值) |
@RequestBody | (获取请求体[POST]) |
@RequestAttribute | (获取request域属性) |
@MatrixVariable | (矩阵变量) |
@RestController
public class ParameterTestController {
// car/2/owner/zhangsan
@GetMapping("/car/{id}/owner/{username}")
public Map<String,Object> getCar(@PathVariable("id") Integer id,
@PathVariable("username") String name,
@PathVariable Map<String,String> pv,
@RequestHeader("User-Agent") String userAgent,
@RequestHeader Map<String,String> header,
@RequestParam("age") Integer age,
@RequestParam("inters") List<String> inters,
@RequestParam Map<String,String> params,
@CookieValue("_ga") String _ga,
@CookieValue("_ga") Cookie cookie){
Map<String,Object> map = new HashMap<>();
// map.put("id",id);
// map.put("name",name);
// map.put("pv",pv);
// map.put("userAgent",userAgent);
// map.put("headers",header);
map.put("age",age);
map.put("inters",inters);
map.put("params",params);
map.put("_ga",_ga);
System.out.println(cookie.getName()+"===>"+cookie.getValue());
return map;
}
@PostMapping("/save")
public Map postMethod(@RequestBody String content){
Map<String,Object> map = new HashMap<>();
map.put("content",content);
return map;
}
//1、语法: 请求路径:/cars/sell;low=34;brand=byd,audi,yd
//2、SpringBoot默认是禁用了矩阵变量的功能
// 手动开启:原理。对于路径的处理。UrlPathHelper进行解析。
// removeSemicolonContent(移除分号内容)支持矩阵变量的
//3、矩阵变量必须有url路径变量才能被解析
@GetMapping("/cars/{path}")
public Map carsSell(@MatrixVariable("low") Integer low,
@MatrixVariable("brand") List<String> brand,
@PathVariable("path") String path){
Map<String,Object> map = new HashMap<>();
map.put("low",low);
map.put("brand",brand);
map.put("path",path);
return map;
}
// /boss/1;age=20/2;age=10
@GetMapping("/boss/{bossId}/{empId}")
public Map boss(@MatrixVariable(value = "age",pathVar = "bossId") Integer bossAge,
@MatrixVariable(value = "age",pathVar = "empId") Integer empAge){
Map<String,Object> map = new HashMap<>();
map.put("bossAge",bossAge);
map.put("empAge",empAge);
return map;
}
}
/car/{path}?xxx=xxx&aaa=ccc 这种传递参数的方式叫做queryString 查询字符串 用@RequestParam注解
/car/{path;low=34;brand=byd,audi,yd} ;这种传递参数的方式叫做矩阵变量
第一种:
//开启SpringBoot的矩阵变量,因为SpringBoot的矩阵变量默认是禁止的,开启需要重写WebMvcConfigurer类中的下面的方法
@Override
public void configurePathMatch(PathMatchConfigurer configurer) {
UrlPathHelper urlPathHelper=new UrlPathHelper();
urlPathHelper.setRemoveSemicolonContent(false);//设置为不移除,这样矩阵变量就会开启
configurer.setUrlPathHelper(urlPathHelper);
}
第二种
@Bean
public WebMvcConfigurer webMvcConfigurer(){
return new WebMvcConfigurer() {
@Override
public void configurePathMatch(PathMatchConfigurer configurer) {
UrlPathHelper urlPathHelper=new UrlPathHelper();
//不移除,后面的内容 矩阵变量矩阵变量功能就可以生效
urlPathHelper.setRemoveSemicolonContent(false);
configurer.setUrlPathHelper(urlPathHelper);
}
};
}
页面上测试
<a href="/cars/sell;low=34;brand=byd,audi,yd">@MatrixVariable(矩阵变量)a>
<a href="/cars/sell;low=34;brand=byd;brand=audi;brand=yd">@MatrixVariable(矩阵变量)a>
<a href="/boss/1;age=20/2;age=10">@MatrixVariable(矩阵变量)/boss/{bossId}/{empId}a>
后台
/**
* 2. SpringBoot默认是禁用了矩阵变量的功能
* 手动开启:原理对于路径的处理 UrlPathHelper进行解析
* removeSemicolonContext(移除分号后的内容)支持矩阵变量的
* @param low
* @param brand
* @return
*/
@GetMapping("cars/{path}")
public Map carSell(@MatrixVariable("low") Integer low,
@MatrixVariable("brand" )List<String> brand,
@PathVariable("path") String path){
Map<String,Object> map=new HashMap<>();
map.put("brand",brand);
map.put("low",low);
map.put("path",path);
return map;
}
/**
* /boss/1;age=20/2;age=10 同样的参数进行参数的绑定
*
*/
@GetMapping("/boss/{bossId}/{empId}")
public Map boss(@MatrixVariable(value="age",pathVar = "bossId") Integer bossAge,
@MatrixVariable(value = "age",pathVar = "empId") Integer empAge){
Map<String,Object> map=new HashMap<>();
map.put("bossAge",bossAge);
map.put("empAge",empAge);
return map;
}
WebRequest、ServletRequest、MultipartRequest、 HttpSession、javax.servlet.http.PushBuilder、Principal、InputStream、Reader、HttpMethod、Locale、TimeZone、ZoneId
ServletRequestMethodArgumentResolver 可以解析以上的部分参数
@Override
public boolean supportsParameter(MethodParameter parameter) {
Class<?> paramType = parameter.getParameterType();
return (WebRequest.class.isAssignableFrom(paramType) ||
ServletRequest.class.isAssignableFrom(paramType) ||
MultipartRequest.class.isAssignableFrom(paramType) ||
HttpSession.class.isAssignableFrom(paramType) ||
(pushBuilder != null && pushBuilder.isAssignableFrom(paramType)) ||
Principal.class.isAssignableFrom(paramType) ||
InputStream.class.isAssignableFrom(paramType) ||
Reader.class.isAssignableFrom(paramType) ||
HttpMethod.class == paramType ||
Locale.class == paramType ||
TimeZone.class == paramType ||
ZoneId.class == paramType);
}
Map、Model(map、model里面的数据会被放在request的请求域 request.setAttribute)、Errors/BindingResult、RedirectAttributes( 重定向携带数据)、ServletResponse(response)、SessionStatus、UriComponentsBuilder、ServletUriComponentsBuilder
Map<String,Object> map, Model model, HttpServletRequest request 都是可以给request域中放数据,
request.getAttribute();
Map、Model类型的参数,会返回 mavContainer.getModel();—> BindingAwareModelMap 是Model 也是Map
mavContainer.getModel(); 获取到值的
可以自动类型转换与格式化,可以级联封装。
/**
* 姓名:
* 年龄:
* 生日:
* 宠物姓名:
* 宠物年龄:
*/
@Data
public class Person {
private String userName;
private Integer age;
private Date birth;
private Pet pet;
}
@Data
public class Pet {
private String name;
private String age;
}
result
ServletModelAttributeMethodProcessor
// Actually invoke the handler.
//DispatcherServlet -- doDispatch
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
mav = invokeHandlerMethod(request, response, handlerMethod); //执行目标方法
//ServletInvocableHandlerMethod
Object returnValue = invokeForRequest(webRequest, mavContainer, providedArgs);
//获取方法的参数值
Object[] args = getMethodArgumentValues(request, mavContainer, providedArgs);
============InvocableHandlerMethod==========================
protected Object[] getMethodArgumentValues(NativeWebRequest request, @Nullable ModelAndViewContainer mavContainer,
Object... providedArgs) throws Exception {
MethodParameter[] parameters = getMethodParameters();
if (ObjectUtils.isEmpty(parameters)) {
return EMPTY_ARGS;
}
Object[] args = new Object[parameters.length];
for (int i = 0; i < parameters.length; i++) {
MethodParameter parameter = parameters[i];
parameter.initParameterNameDiscovery(this.parameterNameDiscoverer);
args[i] = findProvidedArgument(parameter, providedArgs);
if (args[i] != null) {
continue;
}
if (!this.resolvers.supportsParameter(parameter)) {
throw new IllegalStateException(formatArgumentError(parameter, "No suitable resolver"));
}
try {
args[i] = this.resolvers.resolveArgument(parameter, mavContainer, request, this.dataBinderFactory);
}
catch (Exception ex) {
// Leave stack trace for later, exception may actually be resolved and handled...
if (logger.isDebugEnabled()) {
String exMsg = ex.getMessage();
if (exMsg != null && !exMsg.contains(parameter.getExecutable().toGenericString())) {
logger.debug(formatArgumentError(parameter, exMsg));
}
}
throw ex;
}
}
return args;
}
@Nullable
private HandlerMethodArgumentResolver getArgumentResolver(MethodParameter parameter) {
HandlerMethodArgumentResolver result = this.argumentResolverCache.get(parameter);
if (result == null) {
for (HandlerMethodArgumentResolver resolver : this.argumentResolvers) {
if (resolver.supportsParameter(parameter)) {
result = resolver;
this.argumentResolverCache.put(parameter, result);
break;
}
}
}
return result;
}
调用各自 HandlerMethodArgumentResolver 的 resolveArgument 方法即可
public static boolean isSimpleValueType(Class<?> type) {
return (Void.class != type && void.class != type &&
(ClassUtils.isPrimitiveOrWrapper(type) ||
Enum.class.isAssignableFrom(type) ||
CharSequence.class.isAssignableFrom(type) ||
Number.class.isAssignableFrom(type) ||
Date.class.isAssignableFrom(type) ||
Temporal.class.isAssignableFrom(type) ||
URI.class == type ||
URL.class == type ||
Locale.class == type ||
Class.class == type));
}
@Override
@Nullable
public final Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer,
NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception {
Assert.state(mavContainer != null, "ModelAttributeMethodProcessor requires ModelAndViewContainer");
Assert.state(binderFactory != null, "ModelAttributeMethodProcessor requires WebDataBinderFactory");
String name = ModelFactory.getNameForParameter(parameter);
ModelAttribute ann = parameter.getParameterAnnotation(ModelAttribute.class);
if (ann != null) {
mavContainer.setBinding(name, ann.binding());
}
Object attribute = null;
BindingResult bindingResult = null;
if (mavContainer.containsAttribute(name)) {
attribute = mavContainer.getModel().get(name);
}
else {
// Create attribute instance
try {
attribute = createAttribute(name, parameter, binderFactory, webRequest);
}
catch (BindException ex) {
if (isBindExceptionRequired(parameter)) {
// No BindingResult parameter -> fail with BindException
throw ex;
}
// Otherwise, expose null/empty value and associated BindingResult
if (parameter.getParameterType() == Optional.class) {
attribute = Optional.empty();
}
bindingResult = ex.getBindingResult();
}
}
if (bindingResult == null) {
// Bean property binding and validation;
// skipped in case of binding failure on construction.
WebDataBinder binder = binderFactory.createBinder(webRequest, attribute, name);
if (binder.getTarget() != null) {
if (!mavContainer.isBindingDisabled(name)) {
bindRequestParameters(binder, webRequest);
}
validateIfApplicable(binder, parameter);
if (binder.getBindingResult().hasErrors() && isBindExceptionRequired(binder, parameter)) {
throw new BindException(binder.getBindingResult());
}
}
// Value type adaptation, also covering java.util.Optional
if (!parameter.getParameterType().isInstance(attribute)) {
attribute = binder.convertIfNecessary(binder.getTarget(), parameter.getParameterType(), parameter);
}
bindingResult = binder.getBindingResult();
}
// Add resolved attribute and BindingResult at the end of the model
Map<String, Object> bindingResultModel = bindingResult.getModel();
mavContainer.removeAttributes(bindingResultModel);
mavContainer.addAllAttributes(bindingResultModel);
return attribute;
}
WebDataBinder binder = binderFactory.createBinder(webRequest, attribute, name);
WebDataBinder :web数据绑定器,将请求参数的值绑定到指定的JavaBean里面
WebDataBinder 利用它里面的 Converters 将请求数据转成指定的数据类型。再次封装到JavaBean中
GenericConversionService:在设置每一个值的时候,找它里面的所有converter那个可以将这个数据类型(request带来参数的字符串)转换到指定的类型(JavaBean – Integer)
byte – > file
@FunctionalInterfacepublic interface Converter
未来我们可以给WebDataBinder里面放自己的Converter;
private static final class StringToNumber implements Converter
//1、WebMvcConfigurer定制化SpringMVC的功能
@Bean
public WebMvcConfigurer webMvcConfigurer(){
return new WebMvcConfigurer() {
@Override
public void configurePathMatch(PathMatchConfigurer configurer) {
UrlPathHelper urlPathHelper = new UrlPathHelper();
// 不移除;后面的内容。矩阵变量功能就可以生效
urlPathHelper.setRemoveSemicolonContent(false);
configurer.setUrlPathHelper(urlPathHelper);
}
@Override
public void addFormatters(FormatterRegistry registry) {
registry.addConverter(new Converter<String, Pet>() {
@Override
public Pet convert(String source) {
// 啊猫,3
if(!StringUtils.isEmpty(source)){
Pet pet = new Pet();
String[] split = source.split(",");
pet.setName(split[0]);
pet.setAge(Integer.parseInt(split[1]));
return pet;
}
return null;
}
});
}
};
}
InternalResourceView:
@Override
protected void renderMergedOutputModel(
Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
// Expose the model object as request attributes.
exposeModelAsRequestAttributes(model, request);
// Expose helpers as request attributes, if any.
exposeHelpers(request);
// Determine the path for the request dispatcher.
String dispatcherPath = prepareForRendering(request, response);
// Obtain a RequestDispatcher for the target resource (typically a JSP).
RequestDispatcher rd = getRequestDispatcher(request, dispatcherPath);
if (rd == null) {
throw new ServletException("Could not get RequestDispatcher for [" + getUrl() +
"]: Check that the corresponding file exists within your web application archive!");
}
// If already included or response already committed, perform include, else forward.
if (useInclude(request, response)) {
response.setContentType(getContentType());
if (logger.isDebugEnabled()) {
logger.debug("Including [" + getUrl() + "]");
}
rd.include(request, response);
}
else {
// Note: The forwarded resource is supposed to determine the content type itself.
if (logger.isDebugEnabled()) {
logger.debug("Forwarding to [" + getUrl() + "]");
}
rd.forward(request, response);
}
}
暴露模型作为请求域属性
// Expose the model object as request attributes.
exposeModelAsRequestAttributes(model, request);
protected void exposeModelAsRequestAttributes(Map<String, Object> model,
HttpServletRequest request) throws Exception {
//model中的所有数据遍历挨个放在请求域中
model.forEach((name, value) -> {
if (value != null) {
request.setAttribute(name, value);
}
else {
request.removeAttribute(name);
}
});
}
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
web场景自动引入了json场景
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-json</artifactId>
<version>2.3.4.RELEASE</version>
<scope>compile</scope>
</dependency>
try {
this.returnValueHandlers.handleReturnValue(
returnValue, getReturnValueType(returnValue), mavContainer, webRequest);
}
@Override
public void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType,
ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception {
HandlerMethodReturnValueHandler handler = selectHandler(returnValue, returnType);
if (handler == null) {
throw new IllegalArgumentException("Unknown return value type: " + returnType.getParameterType().getName());
}
handler.handleReturnValue(returnValue, returnType, mavContainer, webRequest);
}
RequestResponseBodyMethodProcessor
@Override
public void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType,
ModelAndViewContainer mavContainer, NativeWebRequest webRequest)
throws IOException, HttpMediaTypeNotAcceptableException, HttpMessageNotWritableException {
mavContainer.setRequestHandled(true);
ServletServerHttpRequest inputMessage = createInputMessage(webRequest);
ServletServerHttpResponse outputMessage = createOutputMessage(webRequest);
// Try even with null return value. ResponseBodyAdvice could get involved.
// 使用消息转换器进行写出操作
writeWithMessageConverters(returnValue, returnType, inputMessage, outputMessage);
}
ModelAndView
Model
View
ResponseEntity
ResponseBodyEmitter
StreamingResponseBody
HttpEntity
HttpHeaders
Callable
DeferredResult
ListenableFuture
CompletionStage
WebAsyncTask
有 @ModelAttribute 且为对象类型的
@ResponseBody 注解 ---> RequestResponseBodyMethodProcessor进行处理;
最终最终messageConverter 中MappingJackson2HttpMessageConverter 把对象转为JSON(利用底层的jackson的objectMapper转换的)
@ResponseBody,利用返回值处理器里面的消息转换器进行处理
根据客户端接收能力不同,返回不同媒体类型的数据
比如返回Json或者xml的数据要求
<dependency>
<groupId>com.fasterxml.jackson.dataformatgroupId>
<artifactId>jackson-dataformat-xmlartifactId>
dependency>
只需要改变请求头中Accept字段。Http协议中规定的,告诉服务器本客户端可以接收的数据类型
为了方便内容协商,开启基于请求参数的内容协商功能。
#开启请求参数内容协商模式
spring:
contentnegotiation:
favor-parameter: true
发请求:需要携带format参数
http://localhost:8080/test/person?format=json http://localhost:8080/test/person?format=xml
确定客户端接收什么样的内容类型;
1、Parameter策略优先确定是要返回json数据(获取请求头中的format的值)
2、最终进行内容协商返回给客户端json即可。
• 1、判断当前响应头中是否已经有确定的媒体类型。MediaType
• 2、获取客户端(PostMan、浏览器)支持接收的内容类型。(获取客户端Accept请求头字段)【application/xml】
contentNegotiationManager 内容协商管理器 默认使用基于请求头的策略
HeaderContentNegotiationStrategy 确定客户端可以接收的内容类型
3、遍历循环所有当前系统的 MessageConverter,看谁支持操作这个对象(Person)
4、找到支持操作Person的converter,把converter支持的媒体类型统计出来。
5、客户端需要【application/xml】。服务端能力【10种、json、xml】
6、进行内容协商的最佳匹配媒体类型
浏览器和服务端进行支持的数据类型匹配
7、用 支持 将对象转为 最佳匹配媒体类型 的converter。调用它进行转化 。
导入了jackson处理xml的包,xml的converter就会自动进来
WebMvcConfigurationSupport
jackson2XmlPresent = ClassUtils.isPresent("com.fasterxml.jackson.dataformat.xml.XmlMapper", classLoader);
if (jackson2XmlPresent) {
Jackson2ObjectMapperBuilder builder = Jackson2ObjectMapperBuilder.xml();
if (this.applicationContext != null) {
builder.applicationContext(this.applicationContext);
}
messageConverters.add(new MappingJackson2XmlHttpMessageConverter(builder.build()));
}
/**
* 1. 浏览器发送请求直接返回xml数据 【application/xml】 jacksonXmlConverter
* 2. 如果事ajax请求,返回json [application/json] jacksonJsonConverter
* 3. 如果是硅谷app发送的请求,返回自定义协议的数据 [application/x-guigu] xxxConverter
* 属性值1;属性值2
*
*
* 步骤:
* 1. 添加自定义的MessageCoverter进系统的底层
* 2. 系统底层就会统计出所有的MessageCoverter能进行操作那些类型
* 3. 客户端内容协商(guigu-->guigu)
* @return
*/
实现多协议数据兼容。json、xml、x-guigu
/**
* 自定义的Converter
* 需要继承HttpMessageConverter 然后进行重写所有的方法
* 这里主要展示的是写
*/
public class GuiguCoverter implements HttpMessageConverter<Person> {
@Override
public boolean canRead(Class<?> aClass, MediaType mediaType) {
return false;
}
第一步:
/*写*/
@Override
public boolean canWrite(Class<?> aClass, MediaType mediaType) {
return aClass.isAssignableFrom(Person.class);
}
第二步:
/**
* 服务器要统计所有MessageCoverter都能写出那些内容类型
* application/x-guigu
* @return
*/
@Override
public List<MediaType> getSupportedMediaTypes() {
return MediaType.parseMediaTypes("application/x-guigu"); //规定可以写入那些类型的内容
}
@Override
public Person read(Class<? extends Person> aClass, HttpInputMessage httpInputMessage) throws IOException, HttpMessageNotReadableException {
return null;
}
第三步:
//规定格式是啥:
@Override
public void write(Person person, MediaType mediaType, HttpOutputMessage httpOutputMessage) throws IOException, HttpMessageNotWritableException {
String data=person.getName()+";"+person.getSex()+";"+person.getAge();
第四步:
//写出去
OutputStream body=httpOutputMessage.getBody();
body.write(data.getBytes());
}
}
@Bean
public WebMvcConfigurer webMvcConfigurer(){
return new WebMvcConfigurer() {
@Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
}
}
}
内容协商管理器的内容协商策略
下面进行修改自定义请求参数 内容协商修改的具体方法:
请求方式有两种,一种是请求头 Accept=XXX 一种是请求参数 format=json
在配置类中加入下面代码:
/**
* 请求方式有两种,一种是请求头 Accept=XXX 一种是请求参数 format=json
*/
//自定义内容协商策略
//用请求参数的方法进行请求
//配置协商功能 需要先将内容协商开启
@Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
//Map mediaTypes
Map<String, MediaType> mediaType=new HashMap<>();
mediaType.put("json",MediaType.APPLICATION_JSON);
mediaType.put("xml",MediaType.APPLICATION_XML);
mediaType.put("gg",MediaType.parseMediaType("application/x-guigu"));
//指定支持解析那些参数对应的那些媒体类型
ParameterContentNegotiationStrategy parameterStrategy = new ParameterContentNegotiationStrategy(mediaType);//参数的内容协商策略
configurer.strategies(Arrays.asList(parameterStrategy));//设置内容协商策略
}
协商策略修改之前的:
进行协商策略修改以后的:
有可能我们添加的自定义的功能会覆盖默认很多功能,导致一些默认的功能失效。
大家考虑,上述功能除了我们完全自定义外?SpringBoot有没有为我们提供基于配置文件的快速修改媒体类型功能?怎么配置呢?【提示:参照SpringBoot官方文档web开发内容协商章节】
视图解析:SpringBoot默认不支持 JSP,需要引入第三方模板引擎技术实现页面渲染。
- 目标方法处理的过程中,所有数据都会被放在 ModelAndViewContainer 里面。包括数据和视图地址
- 方法的参数是一个自定义类型对象(从请求参数中确定的),把他重新放在 ModelAndViewContainer
- 任何目标方法执行完成以后都会返回 ModelAndView(数据和视图地址)。
- processDispatchResult 处理派发结果(页面该如何响应)
4.1. render(mv, request, response); 进行页面渲染逻辑
4.1.1. 根据方法的String返回值得到 View 对象【定义了页面的渲染逻辑】
4.1.1.1. 所有的视图解析器尝试是否能根据当前返回值得到View对象
4.1.1.2. 得到了 redirect:/main.html --> Thymeleaf new RedirectView()
4.1.1.3. ContentNegotiationViewResolver 里面包含了下面所有的视图解析器,内部还是利用下面所有视图解析器得到视图对象。
4.1.1.4. view.render(mv.getModelInternal(), request, response); 视图对象调用自定义的render进行页面渲染工作
• RedirectView 如何渲染【重定向到一个页面】
• 1、获取目标url地址
• 2、response.sendRedirect(encodedURL);
视图解析:
返回值以 forward: 开始: new InternalResourceView(forwardUrl); --> 转发request.getRequestDispatcher(path).forward(request, response);
返回值以 redirect: 开始: new RedirectView() --》 render就是重定向
点击查看
thymeleaf、web-starter、devtools、lombok
自动配置好,我们只需要把所有静态资源放到 static 文件夹下
th:insert/replace/include
将公共部分的界面代码抽取出来,在别的界面引用即可
<link href="css/style.css" th:href="@{/css/style.css}" rel="stylesheet">
<link href="css/style-responsive.css" th:href="@{/css/style-responsive.css}" rel="stylesheet">
这样的路径写法就可以动态加入项目名字
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head th:fragment="commonheader">
<div id="leftmenu" class="left-side sticky-left-side">
div>
<div th:include="common :: commonheader"> div>
效果:
<div>
© 2011 The Good Thymes Virtual Grocery
div>
<div th:replace="common :: #leftmenu">div>
效果
<footer>
© 2011 The Good Thymes Virtual Grocery
footer>
<div th:insert="footer :: copy">div>
效果
<div>
<footer>
© 2011 The Good Thymes Virtual Grocery
footer>
div>
@PostMapping("/login")
public String main(User user, HttpSession session, Model model){
if(StringUtils.hasLength(user.getUserName()) && "123456".equals(user.getPassword())){
//把登陆成功的用户保存起来
session.setAttribute("loginUser",user);
//登录成功重定向到main.html; 重定向防止表单重复提交
return "redirect:/main.html";
}else {
model.addAttribute("msg","账号密码错误");
//回到登录页面
return "login";
}
}
@GetMapping("dynamic_table")
public String dynamic_table(Model model){
List<User> users = Arrays.asList(new User("tjk", "123"),
new User("zjj", "123"),
new User("yzy", "123"),
new User("mlh", "123"),
new User("ww", "123"));
model.addAttribute("users",users);
return "table/dynamic_table";
}
}
<table class="display table table-bordered table-striped" id="dynamic-table">
<thead>
<tr>
<th>序号th>
<th>nameth>
<th>ageth>
tr>
thead>
<tbody>
<tr class="gradeX" th:each="user,stats: ${users}">
<td th:text="${stats.count}">td>
<td>[[${user.username}]]td>
<td th:text="${user.password}">td>
tr>
tfoot>
table>
拦截器在底层用到的接口是HandlerInterceptor
preHandle
:是执行请求之前进行拦截
postHandle
:执行请求之后进行执行的拦截器 可以带参数
afterCompletion
:执行请求之后进行执行的拦截器,是最后的拦截器
第一步:
/**
* 登陆检查
* 1. 配置好拦截器需要拦截那些请求
* 2. 把这些配置放到容器中
*/
//应用拦截器必须实现HandlerInterceptor类
@Slf4j
public class LoginIntercepted implements HandlerInterceptor {
/**
* 目标方法执行之前
*/
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
HttpSession session = request.getSession();
StringBuffer requestURL = request.getRequestURL();
log.info("拦截器的请求路径是{}",requestURL);
Object user = session.getAttribute("user");
log.info("preHandle执行了");
//检查登录的逻辑
if(!user.equals("")&&user!=null){
log.info("放行了");
return true;//进行放行操作
}else {
session.setAttribute("msg","请先登录");
// response.sendRedirect("/");//重定向进入首页
request.getRequestDispatcher("/").forward(request,response);
return false;
}
}
/**
* 目标方法拦截之后
*/
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
log.info("postHandle执行了");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
log.info("afterCompletion执行了");
}
}
第二步:
@Configuration
public class AdminMvcConfig implements WebMvcConfigurer {
/**
* 将拦截器加入到容器中
* @param registry
*/
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LoginIntercepted()).
addPathPatterns("/**").//拦截了静态的资源
excludePathPatterns("/","/login","/css/**","/fonts/**","/images/**","/js/**");
}
}
需要注意的是拦截器进行拦截的时候‘/**’也拦截了静态资源,需要后面使用excludePathPatterns进行释放,释放的时候别忘了/js/**
星星
1、根据当前请求,找到HandlerExecutionChain【可以处理请求的handler以及handler的所有 拦截器】
2、先来顺序执行 所有拦截器的 preHandle方法
• 1、如果当前拦截器prehandler返回为true。则执行下一个拦截器的preHandle
• 2、如果当前拦截器返回为false。直接 倒序执行所有已经执行了的拦截器的 afterCompletion;
3、如果任何一个拦截器返回false。直接跳出不执行目标方法
4、所有拦截器都返回True。执行目标方法
5、倒序执行所有拦截器的postHandle方法。
6、前面的步骤有任何异常都会直接倒序触发 afterCompletion
7、页面成功渲染完成以后,也会倒序触发 afterCompletion
<div class="panel-body">
<form role="form" th:action="@{/upload}" method="post" enctype="multipart/form-data">
<div class="form-group">
<label for="exampleInputEmail1">邮箱label>
<input type="email" name="email" class="form-control" id="exampleInputEmail1" placeholder="Enter email">
div>
<div class="form-group">
<label for="exampleInputPassword1">名字label>
<input type="text" name="username" class="form-control" id="exampleInputPassword1" placeholder="Password">
div>
<div class="form-group">
<label for="exampleInputFile">头像label>
<input type="file" name="headerImg" id="exampleInputFile">
div>
<div class="form-group">
<label for="exampleInputFile">生活照label>
<input type="file" name="photos" multiple>
div>
<div class="checkbox">
<label>
<input type="checkbox"> Check me out
label>
div>
<button type="submit" class="btn btn-primary">提交button>
form>
/**
* MultipartFile 自动封装上传来的文件
* @param email
* @param username
* @param headerImg
* @param photos
* @return
*/
@PostMapping("/upload")
public String upload(@RequestParam("email") String email,
@RequestParam("username") String username,
@RequestPart("headerImg")MultipartFile headerImg,
@RequestPart("photos") MultipartFile[] photos) throws IOException {
log.info("上传的信息:email={},username={},headerImg={},photos={}",email,username,headerImg.getSize(),photos.length);
//单文件上传
if(headerImg.getSize()>0) {
String originalFilename = headerImg.getOriginalFilename();
headerImg.transferTo(new File("F://cache//" + originalFilename));
}
//多文件上传
if(photos.length>0){
for (MultipartFile photo:photos){
if(!photo.isEmpty()){
photo.transferTo(new File("F://photo//"+photo.getOriginalFilename()));
}
}
}
return "main";
}
注意配置单文件最大可上传量和总文件最大上传量
#单文件
spring.servlet.multipart.max-file-size=100MB
#最大总容量
spring.servlet.multipart.max-request-size=100MB
MultipartAutoConfiguration
-MultipartProperties
StandardServletMultipartResolver
【文件上传解析器】isMultipart
)并封装(resolveMultipart
,返回MultipartHttpServletRequest
)文件上传请求MultiValueMap
FileCopyUtils
。实现文件流的拷 @PostMapping("/upload")
public String upload(@RequestParam("email") String email,
@RequestParam("username") String username,
@RequestPart("headerImg") MultipartFile headerImg,
@RequestPart("photos") MultipartFile[] photos)
• 默认情况下,Spring Boot提供/error处理所有错误的映射
• 对于机器客户端,它将生成JSON响应,其中包含错误,HTTP状态和异常消息的详细信息。对于浏览器客户端,响应一个“ whitelabel”错误视图,以HTML格式呈现相同的数据
默认情况是这样的:
<section class="error-wrapper text-center">
<h1><img alt="" src="images/404-error.png">h1>
<h2 th:text="${status}">page not foundh2>
<h3 th:text="${message}">We Couldn’t Find This Pageh3>
<p class="nrml-txt" th:text="${trace}">Why not try refreshing you page? Or you can <a href="#">contact our supporta> if the problem persists.p>
<a class="back-btn" th:href="@{/main.html}"> Back To Homea>
section>
status、message、trace
都是json中的数据,可以自己提取
自定义错误页
error/404.html error/5xx.html;有精确的错误状态码页面就匹配精确,没有就找 4xx.html;如果都没有就触发白页
@ControllerAdvice+@ExceptionHandler处理全局异常;底层是 ExceptionHandlerExceptionResolver 支持的
@ResponseStatus+自定义异常 ;底层是 ResponseStatusExceptionResolver ,把responsestatus注解的信息底层调用 response.sendError(statusCode, resolvedReason);tomcat发送的/error
Spring底层的异常,如 参数类型转换异常;DefaultHandlerExceptionResolver 处理框架底层的异常。
response.sendError(HttpServletResponse.SC_BAD_REQUEST, ex.getMessage());
ErrorViewResolver 实现自定义处理异常;
• response.sendError 。error请求就会转给controller
• 你的异常没有任何人能处理。tomcat底层 response.sendError。error请求就会转给controller
• basicErrorController 要去的页面地址是 ErrorViewResolver ;
自定义错误页面
a. error/404.html error/5xx.html
@ControllerAdvice+@ExceptionHandle 处理异常
ErrorViewResolver实现自定义处理异常
实现HandlerExceptionResolver处理异常
ErrorMvcAutoConfiguration自动配置异常处理规则
容器中的类型:DefaultErrorAttributes -> id: errorAttributes
a. public class DefaultErrorAttributes implements ErorAttributes, HandlerExceptionResolver
b. DefaultErrorAttributes:定义错误页面中可以包含哪些数据。
容器中的组件:类型:BasicErrorController --> id:basicErrorController(json+白页 适配响应)
容器中的组件:类型:DefaultErrorViewResolver -> id:conventionErrorViewResolver
如果想要返回页面;就会找error视图【StaticView】。(默认是一个白页)
BasicErrorController
中有两个处理的方法:
1、执行目标方法,目标方法运行期间有任何异常都会被catch、而且标志当前请求结束;并且用 dispatchException
2、进入视图解析流程(页面渲染?)
processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);
3、mv = processHandlerException;处理handler发生的异常,处理完成返回ModelAndView;
a. 遍历所有的 handlerExceptionResolvers,看谁能处理当前异常【HandlerExceptionResolver处理器异常解析器】
b. 系统默认的 异常解析器
1、DefaultErrorAttributes先来处理异常。把异常信息保存到rrequest域,并且返回null;
2、默认没有任何人能处理异常,所以异常会被抛出
• 1、如果没有任何人能处理最终底层就会发送 /error 请求。会被底层的BasicErrorController处理
• 2、解析错误视图;遍历所有的 ErrorViewResolver 看谁能解析。
3、 默认的 DefaultErrorViewResolver ,作用是把响应状态码作为错误页的地址,error/500.html
4、模板引擎最终响应这个页面 error/500.html
拦截器:
@ServletComponentScan(basePackages = "com.tjk.admin.servlet")
:指定原生Servlet组件都放在那里
@WebServlet(urlPatterns = "/my")
:效果:直接响应,没有经过Spring的拦截器?
@WebFilter(urlPatterns={"/css/*","/images/*"})
@WebListener
推荐使用这种方式
扩展
:DispatchServlet 如何注册进来
@ServletComponentScan(basePackages="com.tjk.practice5.servlet")
@SpringBootApplication
public class Practice5Application {
public static void main(String[] args) {
SpringApplication.run(Practice5Application.class, args);
}
}
@WebServlet(urlPatterns = "/my")
public class Myservlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().write("6666");
}
}
@Slf4j
@WebFilter(urlPatterns = {"/css/*","/images/*"})
public class MyFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
log.info("Filter初始化完成");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
log.info("真正的过滤器处理逻辑");
filterChain.doFilter(servletRequest,servletResponse);
}
@Override
public void destroy() {
log.info("Filter已经销毁");
}
@Slf4j
@WebListener()
public class MyListeren implements ServletContextListener {
public void contextInitialized(ServletContextEvent sce) {
log.info("MyListeren已经初始化完成");
}
public void contextDestroyed(ServletContextEvent sce) {
log.info("MyListeren已经销毁");
}
}
ServletRegistrationBean, FilterRegistrationBean, and ServletListenerRegistrationBean
@Configuration
public class MyRegistConfig {
@Bean
public ServletRegistrationBean myServlet(){
MyServlet myServlet = new MyServlet();
return new ServletRegistrationBean(myServlet,"/my","/my02");
}
@Bean
public FilterRegistrationBean myFilter(){
MyFilter myFilter = new MyFilter();
// return new FilterRegistrationBean(myFilter,myServlet());
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(myFilter);
filterRegistrationBean.setUrlPatterns(Arrays.asList("/my","/css/*"));
return filterRegistrationBean;
}
@Bean
public ServletListenerRegistrationBean myListener(){
MySwervletContextListener mySwervletContextListener = new MySwervletContextListener();
return new ServletListenerRegistrationBean(mySwervletContextListener);
}
}
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-tomcatartifactId>
exclusion>
exclusions>
dependency>
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;
import org.springframework.stereotype.Component;
@Component
public class CustomizationBean implements WebServerFactoryCustomizer<ConfigurableServletWebServerFactory> {
@Override
public void customize(ConfigurableServletWebServerFactory server) {
server.setPort(9000);
}
}
@Configuration
public class AdminWebConfig implements WebMvcConfigurer
@EnableWebMvc + WebMvcConfigurer —— @Bean 可以全面接管SpringMVC,所有规则全部自己重新配置; 实现定制和扩展功能
原理:
场景starter - xxxxAutoConfiguration - 导入xxx组件 - 绑定xxxProperties – 绑定配置文件项
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-data-jdbcartifactId>
dependency>
数据库驱动?
为什么导入JDBC场景,官方不导入驱动?官方不知道我们接下要操作什么数据库。
数据库版本和驱动版本对应
默认版本:<mysql.version>8.0.22mysql.version>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
dependency>
想要修改版本
1、直接依赖引入具体版本(maven的就近依赖原则)
2、重新声明版本(maven的属性的就近优先原则)
<properties>
<java.version>1.8java.version>
<mysql.version>5.1.49mysql.version>
properties>
@Configuration(proxyBeanMethods = false)
@Conditional(PooledDataSourceCondition.class)
@ConditionalOnMissingBean({ DataSource.class, XADataSource.class })
@Import({ DataSourceConfiguration.Hikari.class, DataSourceConfiguration.Tomcat.class,
DataSourceConfiguration.Dbcp2.class, DataSourceConfiguration.OracleUcp.class,
DataSourceConfiguration.Generic.class, DataSourceJmxConfiguration.class })
protected static class PooledDataSourceConfiguration
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/student
username: root
password: tiger
#设置多少秒请求即超时
jdbc:
template:
query-timeout: 3s
package com.tjk.practice5;
import lombok.extern.log4j.Log4j;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.jdbc.core.JdbcTemplate;
@Slf4j
@SpringBootTest
class Practice5ApplicationTests {
@Autowired
JdbcTemplate jdbcTemplate;
@Test
void contextLoads() {
Long aLong = jdbcTemplate.queryForObject("select count(*) from student", Long.class);
log.info("当前查到的总数为{}",aLong);
}
}
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整合第三方技术的两种方式
• 自定义
• 找starter
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>1.1.17version>
dependency>
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
destroy-method="close">
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="maxActive" value="20" />
<property name="initialSize" value="1" />
<property name="maxWait" value="60000" />
<property name="minIdle" value="1" />
<property name="timeBetweenEvictionRunsMillis" value="60000" />
<property name="minEvictableIdleTimeMillis" value="300000" />
<property name="testWhileIdle" value="true" />
<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" />
<property name="poolPreparedStatements" value="true" />
<property name="maxOpenPreparedStatements" value="20" />
@Configuration
public class MyDataSourceConfigurtion {
@ConfigurationProperties("spring.datasource")//该配置类是,将配置文件和配置类中的属性相互绑定
@Bean
public DataSource dataSource(){
DruidDataSource druidDataSource = new DruidDataSource();
return druidDataSource;
}
}
@ConfigurationProperties("spring.datasource")//该配置类是,将配置文件和配置类中的属性相互绑定
<servlet>
<servlet-name>DruidStatView</servlet-name>
<servlet-class>com.alibaba.druid.support.http.StatViewServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DruidStatView</servlet-name>
<url-pattern>/druid/*
/**
* 配置druid的监控页功能
*/
@Bean
public ServletRegistrationBean servletRegistrationBean(){
StatViewServlet statViewServlet = new StatViewServlet();
ServletRegistrationBean<StatViewServlet> statViewServletServletRegistrationBean = new ServletRegistrationBean<>(statViewServlet, "/druid/*");
return statViewServletServletRegistrationBean;
}
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
... ...
<property name="filters" value="stat" />
</bean>
druidDataSource.setFilters("stat");//打开了druid监控功能
@Configuration
public class MyDataSourceConfigurtion {
@ConfigurationProperties("spring.datasource")//该配置类是,将配置文件和配置类中的属性相互绑定
@Bean
public DataSource dataSource() throws SQLException {
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setFilters("stat");//打开了druid监控功能
return druidDataSource;
}
效果:
直接访问注册的servlet路径就可以进行sql的监控
<filter>
<filter-name>DruidWebStatFilterfilter-name>
<filter-class>com.alibaba.druid.support.http.WebStatFilterfilter-class>
<init-param>
<param-name>exclusionsparam-name>
<param-value>*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*param-value>
init-param>
filter>
<filter-mapping>
<filter-name>DruidWebStatFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
@Bean
public FilterRegistrationBean filterRegistrationBean(){
WebStatFilter webStatFilter=new WebStatFilter();
FilterRegistrationBean<WebStatFilter> filterFilterRegistrationBean = new FilterRegistrationBean<>(webStatFilter);
filterFilterRegistrationBean.setUrlPatterns(Arrays.asList("/*"));//拦截所有的路径请求
filterFilterRegistrationBean.addInitParameter("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*,/sql");//排除拦截的请求
return filterFilterRegistrationBean;
}
web应用的监控已经开启
Url监控
防火墙:需要在数据源的配置上加上wall参数
需要给servlet设置初始化参数loginUsername、loginPassword
@Bean
public ServletRegistrationBean servletRegistrationBean(){
StatViewServlet statViewServlet = new StatViewServlet();
ServletRegistrationBean<StatViewServlet> servletRegistrationBean = new ServletRegistrationBean<>(statViewServlet, "/druid/*");
servletRegistrationBean.addInitParameter("loginUsername","tjk");
servletRegistrationBean.addInitParameter("loginPassword","zjj");
return servletRegistrationBean;
}
@ConfigurationProperties("spring.datasource")//该配置类是,将配置文件和配置类中的属性相互绑定
@Bean
public DataSource dataSource() throws SQLException {
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setFilters("stat,wall");//打开了druid监控功能
druidDataSource.setMaxActive(10);//设置最大活跃数
return druidDataSource;
}
druidDataSource.setMaxActive(10);//设置最大活跃数
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.17</version>
</dependency>
spring.datasource.druid
DruidSpringAopConfiguration.class
, 监控SpringBean的;配置项:spring.datasource.druid.aop-patterns
DruidStatViewServletConfiguration.class
, 监控页的配置:spring.datasource.druid.stat-view-servlet
;默认开启 private static final String FILTER_STAT_PREFIX = "spring.datasource.druid.filter.stat";
private static final String FILTER_CONFIG_PREFIX = "spring.datasource.druid.filter.config";
private static final String FILTER_ENCODING_PREFIX = "spring.datasource.druid.filter.encoding";
private static final String FILTER_SLF4J_PREFIX = "spring.datasource.druid.filter.slf4j";
private static final String FILTER_LOG4J_PREFIX = "spring.datasource.druid.filter.log4j";
private static final String FILTER_LOG4J2_PREFIX = "spring.datasource.druid.filter.log4j2";
private static final String FILTER_COMMONS_LOG_PREFIX = "spring.datasource.druid.filter.commons-log";
private static final String FILTER_WALL_PREFIX = "spring.datasource.druid.filter.wall";
spring:
datasource:
url: jdbc:mysql://localhost:3306/db_account
username: root
password: 123456
driver-class-name: com.mysql.jdbc.Driver
druid:
aop-patterns: com.atguigu.admin.* #监控SpringBean
filters: stat,wall # 底层开启功能,stat(sql监控),wall(防火墙)
stat-view-servlet: # 配置监控页功能
enabled: true
login-username: admin
login-password: admin
resetEnable: false
web-stat-filter: # 监控web
enabled: true
urlPattern: /*
exclusions: '*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*'
filter:
stat: # 对上面filters里面的stat的详细配置
slow-sql-millis: 1000
logSlowSql: true
enabled: true
wall:
enabled: true
config:
drop-table-allow: false
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未来每一个微服务在云上部署以后,我们都需要对其进行监控、追踪、审计、控制等。SpringBoot就抽取了Actuator场景,使得我们每个微服务快速引用即可获得生产级别的应用监控、审计等功能。
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-actuatorartifactId>
dependency>
management:
endpoints:
enabled-by-default: true #暴露所有端点信息
web:
exposure:
include: '*' #以web方式暴露
测试
http://localhost:8080/actuator/beans
http://localhost:8080/actuator/configprops
http://localhost:8080/actuator/metrics
http://localhost:8080/actuator/metrics/jvm.gc.pause
http://localhost:8080/actuator/endpointName/detailPath
https://github.com/codecentric/spring-boot-admin
ID | 描述 |
---|---|
auditevents | 暴露当前应用程序的审核事件信息。需要一个AuditEventRepository组件。 |
beans | 显示应用程序中所有Spring Bean的完整列表。 |
caches | 暴露可用的缓存。 |
conditions | 显示自动配置的所有条件信息,包括匹配或不匹配的原因。configprops |
env | 暴露Spring的属性ConfigurableEnvironment |
flyway | 显示已应用的所有Flyway数据库迁移。需要一个或多个Flyway组件。 |
health | 显示应用程序运行状况信息。 |
httptrace | 显示HTTP跟踪信息(默认情况下,最近100个HTTP请求-响应)。需要一个HttpTraceRepository组件。 |
info | 显示应用程序信息。 |
integrationgraph | 显示Spring integrationgraph 。需要依赖spring-integration-core。 |
loggers | 显示和修改应用程序中日志的配置。 |
liquibase | 显示已应用的所有Liquibase数据库迁移。需要一个或多个Liquibase组件。 |
metrics | 显示当前应用程序的“指标”信息。 |
mappings | 显示所有@RequestMapping路径列表。 |
scheduledtasks | 显示应用程序中的计划任务。 |
sessions | 允许从Spring Session支持的会话存储中检索和删除用户会话。需要使用Spring Session的基于Servlet的Web应用程序。 |
shutdown | 使应用程序正常关闭。默认禁用。 |
startup | 显示由ApplicationStartup收集的启动步骤数据。需要使用SpringApplication进行配置BufferingApplicationStartup。 |
threaddump | 执行线程转储。 |
如果您的应用程序是Web应用程序(Spring MVC,Spring WebFlux或Jersey),则可以使用以下附加端点:
ID | 描述 |
---|---|
heapdump | 返回hprof堆转储文件。 |
jolokia | 通过HTTP暴露JMX bean(需要引入Jolokia,不适用于WebFlux)。需要引入依赖jolokia-core。 |
logfile | 返回日志文件的内容(如果已设置logging.file.name或logging.file.path属性)。支持使用HTTPRange标头来检索部分日志文件的内容。 |
prometheus | 以Prometheus服务器可以抓取的格式公开指标。需要依赖micrometer-registry-prometheus。 |
最常用的Endpoint
• Health:监控状况
• Metrics:运行时指标
• Loggers:日志记录
健康检查端点,我们一般用于在云平台,平台会定时的检查应用的健康状况,我们就需要Health Endpoint可以为平台返回当前应用的一系列组件健康状况的集合。
提供详细的、层级的、空间指标信息,这些信息可以被pull(主动推送)或者push(被动获取)方式得到;
management:
endpoint:
beans:
enabled: true
management:
endpoints:
enabled-by-default: false
endpoint:
beans:
enabled: true
health:
enabled: true
ID | JMX | Web |
---|---|---|
auditevents | Yes | No |
beans | Yes | No |
caches | Yes | No |
conditions | Yes | No |
configprops | Yes | No |
env | Yes | No |
flyway | Yes | No |
health | Yes | Yes |
heapdump | N/A | No |
httptrace | Yes | No |
info | Yes | Yes |
integrationgraph | Yes | No |
jolokia | N/A | No |
logfile | N/A | No |
loggers | Yes | No |
liquibase | Yes | No |
metrics | Yes | No |
mappings | Yes | No |
prometheus | N/A | No |
scheduledtasks | Yes | No |
sessions | Yes | No |
shutdown | Yes | No |
startup | Yes | No |
threaddump | Yes | No |
import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;
@Component
public class MyHealthIndicator implements HealthIndicator {
@Override
public Health health() {
int errorCode = check(); // perform some specific health check
if (errorCode != 0) {
return Health.down().withDetail("Error Code", errorCode).build();
}
return Health.up().build();
}
}
构建Health
Health build = Health.down()
.withDetail("msg", "error service")
.withDetail("code", "500")
.withException(new RuntimeException())
.build();
management:
health:
enabled: true
show-details: always #总是显示详细信息。可显示每个模块的状态信息
@Component
public class MyComHealthIndicator extends AbstractHealthIndicator {
/**
* 真实的检查方法
* @param builder
* @throws Exception
*/
@Override
protected void doHealthCheck(Health.Builder builder) throws Exception {
//mongodb。 获取连接进行测试
Map<String,Object> map = new HashMap<>();
// 检查完成
if(1 == 2){
// builder.up(); //健康
builder.status(Status.UP);
map.put("count",1);
map.put("ms",100);
}else {
// builder.down();
builder.status(Status.OUT_OF_SERVICE);
map.put("err","连接超时");
map.put("ms",3000);
}
builder.withDetail("code",100)
.withDetails(map);
}
}
常用两种方式
info:
appName: boot-admin
version: 2.0.1
mavenProjectName: @project.artifactId@ #使用@@可以获取maven的pom文件值
mavenProjectVersion: @project.version@
import java.util.Collections;
import org.springframework.boot.actuate.info.Info;
import org.springframework.boot.actuate.info.InfoContributor;
import org.springframework.stereotype.Component;
@Component
public class ExampleInfoContributor implements InfoContributor {
@Override
public void contribute(Info.Builder builder) {
builder.withDetail("example",
Collections.singletonMap("key", "value"));
}
}
http://localhost:8080/actuator/info 会输出以上方式返回的所有info信息
class MyService{
Counter counter;
public MyService(MeterRegistry meterRegistry){
counter = meterRegistry.counter("myservice.method.running.counter");
}
public void hello() {
counter.increment();
}
}
//也可以使用下面的方式
@Bean
MeterBinder queueSize(Queue queue) {
return (registry) -> Gauge.builder("queueSize", queue::size).register(registry);
}
@Component
@Endpoint(id = "container")
public class DockerEndpoint {
@ReadOperation
public Map getDockerInfo(){
return Collections.singletonMap("info","docker started...");
}
@WriteOperation
private void restartDocker(){
System.out.println("docker restarted....");
}
}
场景:开发ReadinessEndpoint来管理程序是否就绪,或者LivenessEndpoint来管理程序是否存活;
当然,这个也可以直接使用
此链接
为了方便多环境适配,springboot简化了profile功能。
java -jar xxx.jar --spring.profiles.active=prod --person.name=haha
@Configuration(proxyBeanMethods = false)
@Profile("production")
public class ProductionConfiguration {
// ...
}
spring.profiles.group.production[0]=proddb
spring.profiles.group.production[1]=prodmq
使用:--spring.profiles.active=production 激活
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常用:Java属性文件、YAML文件、环境变量、命令行参数
(1). classpath 根路径
(2) . classpath 根路径下config目录
(3) . jar包当前目录
(4) . jar包当前目录的config目录
(5) . /config子目录的直接子目录
starter-pom引入 autoconfigurer 包
1. autoconfigure包中配置使用 META-INF/spring.factories 中 EnableAutoConfiguration 的值,使得项目启动加载指定的自动配置类
2. 编写自动配置类 xxxAutoConfiguration -> xxxxProperties
2.1. @Configuration
2.2. @Conditional
2.3. @EnableConfigurationProperties
2.4@Bean
3. 引入starter — xxxAutoConfiguration — 容器中放入组件 ---- 绑定xxxProperties ---- 配置项
atguigu-hello-spring-boot-starter(启动器)
atguigu-hello-spring-boot-starter-autoconfigure(自动配置包)
Spring原理Spring注解、SpringMVC原理、自动配置原理、SpringBoot原理
public interface Bootstrapper {
/**
* Initialize the given {@link BootstrapRegistry} with any required registrations.
* @param registry the registry to initialize
*/
void intitialize(BootstrapRegistry registry);
}
@FunctionalInterface
public interface ApplicationRunner {
/**
* Callback used to run the bean.
* @param args incoming application arguments
* @throws Exception on error
*/
void run(ApplicationArguments args) throws Exception;
}
@FunctionalInterface
public interface CommandLineRunner {
/**
* Callback used to run the bean.
* @param args incoming main method arguments
* @throws Exception on error
*/
void run(String... args) throws Exception;
}
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ApplicationContextInitializer
ApplicationListener
SpringApplicationRunListener