SpringBoot监听机制-以及使用
11-SpringBoot事件监听
Java中的事件监听机制定义了以下几个角色：
①事件：Event，继承 java.util.EventObject 类的对象
②事件源：Source ，任意对象Object
③监听器：Listener，实现 java.util.EventListener 接口 的对象
SpringBoot 在项目启动时，会对几个监听器进行回调，我们可以实现这些监听器接口，在项目启动时完成一些操作。
-
ApplicationContextInitializer、
-
SpringApplicationRunListener、
-
CommandLineRunner、
-
ApplicationRunner
自定义监听器的启动时机：MyApplicationRunner和MyCommandLineRunner都是当项目启动后执行，使用@Component放入容器即可使用
yApplicationRunner
/**
* 当项目启动后执行run方法。
* 缓存数据
*/
@Component
public class MyApplicationRunner implements ApplicationRunner {
@Override
public void run(ApplicationArguments args) throws Exception {
System.out.println("ApplicationRunner...run");
System.out.println(Arrays.asList(args.getSourceArgs()));
}
}
MyCommandLineRunner
@Component
public class MyCommandLineRunner implements CommandLineRunner {
@Override
public void run(String... args) throws Exception {
System.out.println("CommandLineRunner...run");
System.out.println(Arrays.asList(args));
}
}
MyApplicationContextInitializer的使用要在resource文件夹下添加META-INF/spring.factories
org.springframework.context.ApplicationContextInitializer=com.itheima.springbootlistener.listener.MyApplicationContextInitializer
@Component
public class MyApplicationContextInitializer implements ApplicationContextInitializer {
@Override
public void initialize(ConfigurableApplicationContext applicationContext) {
System.out.println("ApplicationContextInitializer....initialize");
}
}
MySpringApplicationRunListener的使用要添加构造器
public class MySpringApplicationRunListener implements SpringApplicationRunListener {
public MySpringApplicationRunListener(SpringApplication application, String[] args) {
}
@Override
public void starting() {
System.out.println("starting...项目启动中");
}
@Override
public void environmentPrepared(ConfigurableEnvironment environment) {
System.out.println("environmentPrepared...环境对象开始准备");
}
@Override
public void contextPrepared(ConfigurableApplicationContext context) {
System.out.println("contextPrepared...上下文对象开始准备");
}
@Override
public void contextLoaded(ConfigurableApplicationContext context) {
System.out.println("contextLoaded...上下文对象开始加载");
}
@Override
public void started(ConfigurableApplicationContext context) {
System.out.println("started...上下文对象加载完成");
}
@Override
public void running(ConfigurableApplicationContext context) {
System.out.println("running...项目启动完成，开始运行");
}
@Override
public void failed(ConfigurableApplicationContext context, Throwable exception) {
System.out.println("failed...项目启动失败");
}
}
12-SpringBoot流程分析-初始化
-
配置启动引导类（判断是否有启动主类）
-
判断是否是Web环境
-
获取初始化类、监听器类
13-SpringBoot流程分析-run
-
启动计时器
-
执行监听器
-
准备环境
-
打印banner：可以resource下粘贴自定义的banner
-
创建context
refreshContext(context);执行refreshContext方法后才真正创建Bean
14-SpringBoot监控-actuator基本使用
①导入依赖坐标
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-actuatorartifactId>
dependency>
②访问http://localhost:8080/acruator
{
"_links":{
"self":{
"href":"http://localhost:8080/actuator",
"templated":false
},
"health":{
"href":"http://localhost:8080/actuator/health",
"templated":false
},
"health-component-instance":{
"href":"http://localhost:8080/actuator/health/{component}/{instance}",
"templated":true
},
"health-component":{
"href":"http://localhost:8080/actuator/health/{component}",
"templated":true
},
"info":{
"href":"http://localhost:8080/actuator/info",
"templated":false
}
}
}
http://localhost:8080/actuator/info
在application.properties中配置
info.name=lucy
info.age=99
http://localhost:8080/actuator/health
开启健康检查详细信息
management.endpoint.health.show-details=always
{
"status":"UP",
"details":{
"diskSpace":{
"status":"UP",
"details":{
"total":159579508736,
"free":13558104064,
"threshold":10485760
}
},
"redis":{
"status":"UP",
"details":{
"version":"2.4.5"
}
}
}
}
15-SpringBoot监控-actuator开启所有endpoint
开启所有endpoint
在application.properties中配置：
management.endpoints.web.exposure.include=*
开启所有endpoint的返回结果：
{
"_links":{
"self":{
"href":"http://localhost:8080/actuator",
"templated":false
},
"auditevents":{
"href":"http://localhost:8080/actuator/auditevents",
"templated":false
},
"beans":{
"href":"http://localhost:8080/actuator/beans",
"templated":false
},
"caches-cache":{
"href":"http://localhost:8080/actuator/caches/{cache}",
"templated":true
},
"caches":{
"href":"http://localhost:8080/actuator/caches",
"templated":false
},
"health-component-instance":{
"href":"http://localhost:8080/actuator/health/{component}/{instance}",
"templated":true
},
"health":{
"href":"http://localhost:8080/actuator/health",
"templated":false
},
"health-component":{
"href":"http://localhost:8080/actuator/health/{component}",
"templated":true
},
"conditions":{
"href":"http://localhost:8080/actuator/conditions",
"templated":false
},
"configprops":{
"href":"http://localhost:8080/actuator/configprops",
"templated":false
},
"env":{
"href":"http://localhost:8080/actuator/env",
"templated":false
},
"env-toMatch":{
"href":"http://localhost:8080/actuator/env/{toMatch}",
"templated":true
},
"info":{
"href":"http://localhost:8080/actuator/info",
"templated":false
},
"loggers":{
"href":"http://localhost:8080/actuator/loggers",
"templated":false
},
"loggers-name":{
"href":"http://localhost:8080/actuator/loggers/{name}",
"templated":true
},
"heapdump":{
"href":"http://localhost:8080/actuator/heapdump",
"templated":false
},
"threaddump":{
"href":"http://localhost:8080/actuator/threaddump",
"templated":false
},
"metrics-requiredMetricName":{
"href":"http://localhost:8080/actuator/metrics/{requiredMetricName}",
"templated":true
},
"metrics":{
"href":"http://localhost:8080/actuator/metrics",
"templated":false
},
"scheduledtasks":{
"href":"http://localhost:8080/actuator/scheduledtasks",
"templated":false
},
"httptrace":{
"href":"http://localhost:8080/actuator/httptrace",
"templated":false
},
"mappings":{
"href":"http://localhost:8080/actuator/mappings",
"templated":false
}
}
}
16-SpringBoot监控-springboot admin图形化界面使用
SpringBoot Admin 有两个角色，客户端(Client)和服务端(Server)。
以下为创建服务端和客户端工程步骤：
admin-server：
①创建 admin-server 模块
②导入依赖坐标 admin-starter-server
<dependency>
<groupId>de.codecentricgroupId>
<artifactId>spring-boot-admin-starter-serverartifactId>
dependency>
③在引导类上启用监控功能@EnableAdminServer
@EnableAdminServer
@SpringBootApplication
public class SpringbootAdminServerApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootAdminServerApplication.class, args);
}
}
admin-client：
①创建 admin-client 模块
②导入依赖坐标 admin-starter-client
<dependency>
<groupId>de.codecentricgroupId>
<artifactId>spring-boot-admin-starter-clientartifactId>
dependency>
③配置相关信息：server地址等
# 执行admin.server地址
spring.boot.admin.client.url=http://localhost:9000
management.endpoint.health.show-details=always
management.endpoints.web.exposure.include=*
④启动server和client服务，访问server
17-SpringBoot部署
SpringBoot 项目开发完毕后，支持两种方式部署到服务器：
①jar包(官方推荐)
②war包
更改pom文件中的打包方式为war
修改启动类
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
@SpringBootApplication
public class SpringbootDeployApplication extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(SpringbootDeployApplication.class, args);
}
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return builder.sources(SpringbootDeployApplication.class);
}
}
指定打包的名称
<build>
<finalName>springbootfinalName>
<plugins>
<plugin>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-maven-pluginartifactId>
plugin>
plugins>
build>