Spring的纯注解配置
1.环境搭建
1.1.创建工程
1.2.待改造的问题
我们发现，之所以我们现在离不开xml配置文件，是因为我们有一处很关键的配置，如果他要也能用注解配置，那么我们就可以脱离xml文件了：
1.2.1.jdbc配置
<context:property-placeholder location="classpath:db.properties">context:property-placeholder>
<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="${jdbc.password}" />
<property name="driverClassName" value="${jdbc.driver}" />
<property name="maxActive" value="10" />
<property name="minIdle" value="5" />
bean>
1.2.2.mybatis配置
<bean id="sessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource">property>
<property name="typeAliasesPackage" value="com.by.pojo">property>
bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.by.mapper">property>
<property name="sqlSessionFactoryBeanName" value="sessionFactoryBean">property>
bean>
1.2.3.transactional配置
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource">property>
bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
1.2.4.service配置
<context:component-scan base-package="com.by.service">context:component-scan>
1.2.5.springmvc配置
<context:component-scan base-package="com.by.controller,com.by.exception">context:component-scan>
<mvc:annotation-driven conversion-service="cs">mvc:annotation-driven>
<bean id="cs" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<set>
<bean class="com.by.converter.MyDateConverter">bean>
set>
property>
bean>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/">property>
<property name="suffix" value=".jsp">property>
bean>
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="5242880" />
<property name="defaultEncoding" value="UTF-8" />
bean>
<mvc:resources location="/head/" mapping="/head/**"/>
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/account/**"/>
<mvc:exclude-mapping path="/account/login">mvc:exclude-mapping>
<bean class="com.by.interceptor.LoginInterceptor">bean>
mvc:interceptor>
mvc:interceptors>
1.2.6.servlet配置
<context-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:applicationContext-*.xmlparam-value>
context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
listener-class>
listener>
<servlet>
<servlet-name>springmvcservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:springmvc.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>springmvcservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
<filter>
<filter-name>CharacterEncodingFilterfilter-name>
<filter-class>
org.springframework.web.filter.CharacterEncodingFilter
filter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>UTF-8param-value>
init-param>
filter>
<filter-mapping>
<filter-name>CharacterEncodingFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
2.新注解说明
2.1.@Configuration
-
作用：
用于指定当前类是一个spring配置类，可替换xml配置文件，作用和在spring的xml配置文件中的：
-
示例代码
/** * spring的配置类 */ @Configuration//等价于，当从一个类上加载到该注解时会创建spring容器 public class SpringConfiguration{ }
2.2.@ComponentScan
-
作用：
用于指定spring在初始化容器时要扫描的包。作用和在spring的xml配置文件中的：
-
属性：
basePackages：用于指定要扫描的包。和该注解中的value属性作用一样。
-
示例代码
/** * spring的配置类 */ @Configuration @ComponentScan(basePackages = "com.by")//等价于
2.3.@Bean
-
作用：
该注解只能写在方法上，表明使用此方法创建一个对象，并且放入spring容器。作用和在spring的xml配置文件中的：
-
属性：
name：给当前@Bean注解方法创建的对象指定一个名称(即bean的id）。
-
示例代码
public class Dog { private String nam; private Integer age; //set get...... }@Bean public Dog dog(){ Dog dog = new Dog(); dog.setNam("二狗"); dog.setAge(18); return dog; }
2.4.@PropertySource
-
作用：
用于加载.properties文件中的配置。作用和在spring的xml配置文件中的：
-
属性：
value[]：用于指定properties文件位置。如果是在类路径下，需要写上classpath:
-
示例代码
#config.properties nam=二狗 age=18@Configuration @PropertySource("classpath:config.properties") public class SpringConfiguration { @Value("${nam}") private String nam; @Value("${age}") private Integer age; @Bean public Dog dog(){ Dog dog = new Dog(); dog.setNam(nam); dog.setAge(age); return dog; } }
2.5.@Import
-
作用：
@Import注解是用来导入配置类或者一些需要前置加载的类。作用和在spring的xml配置文件中的：
-
属性：
value[]：用于指定其他配置类的字节码。
-
示例代码
@Configuration @ComponentScan(basePackages = "com.by") @Import({Configuration_Other.class}) public class SpringConfiguration { } @PropertySource("classpath:config.properties") public class Configuration_Other { }
3.Spring的纯注解配置
3.1.JdbcConfig
package com.by.config;
import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.PropertySource;
import javax.sql.DataSource;
@PropertySource({"classpath:db.properties"})//3.2.MybatisConfig
package com.by.config;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.context.annotation.Bean;
import javax.annotation.Resource;
import javax.sql.DataSource;
public class MyBatisConfig {
@Bean("sessionFactoryBean")
public SqlSessionFactoryBean getSqlSessionFactoryBean(DataSource dataSource){
SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
sessionFactoryBean.setDataSource(dataSource);
return sessionFactoryBean;
}
@Bean
public MapperScannerConfigurer getMapperScannerConfigurer(){
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setBasePackage("com.by.mapper");
mapperScannerConfigurer.setSqlSessionFactoryBeanName("sessionFactoryBean");
return mapperScannerConfigurer;
}
}
3.3.TxConfig
package com.by.config;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import javax.sql.DataSource;
public class TxManagerConfig {
@Bean
public PlatformTransactionManager getPlatformTransactionManager(DataSource dataSource){
DataSourceTransactionManager transactionManager = new DataSourceTransactionManager();
transactionManager.setDataSource(dataSource);
return transactionManager;
}
}
3.4.SpringConfig
package com.by.config;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.transaction.annotation.EnableTransactionManagement;
@Configuration
@Import({DataSourceConfig.class, MyBatisConfig.class, TxManagerConfig.class})
@ComponentScan("com.by.service")
@EnableTransactionManagement //等价于3.5.SpringMvcConfig
package com.by.config;
import com.by.converter.DateConverter;
import com.by.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
@Configuration
@ComponentScan({"com.by.controller"})
@EnableWebMvc //
public class SpringmvcConfig implements WebMvcConfigurer {
@Bean
public InternalResourceViewResolver getInternalResourceViewResolver(){
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/pages/");
viewResolver.setSuffix(".jsp");
return viewResolver;
}
@Bean("multipartResolver")
public CommonsMultipartResolver getCommonsMultipartResolver(){
CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
multipartResolver.setMaxUploadSize(5242880);
multipartResolver.setDefaultEncoding("UTF-8");
return multipartResolver;
}
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/account/**").excludePathPatterns("/user/**");
}
@Override
public void addFormatters(FormatterRegistry registry) {
registry.addConverter(new DateConverter());
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/head/**").addResourceLocations("/head/");
}
}
3.6.WebConfig
package com.by.config;
import org.springframework.web.filter.CharacterEncodingFilter;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
import javax.servlet.Filter;
/**
* 当类扩展了AbstractAnnotationConfigDispatcherServletlnitializer并将其部署到 Servlet容器时，
* 容器会自动发现它，并用它来配置Servlet环境
*/
public class WebConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
//加载Spring配置类
protected Class<?>[] getRootConfigClasses() {
return new Class[]{ServiceConfig.class};
}
//加载SpringMVC配置类
protected Class<?>[] getServletConfigClasses() {
return new Class[]{SpringmvcConfig.class};
}
//设置SpringMVC请求地址拦截规则
protected String[] getServletMappings() {
return new String[]{"/"};
}
//设置post请求中文乱码过滤器
@Override
protected Filter[] getServletFilters() {
CharacterEncodingFilter filter = new CharacterEncodingFilter();
filter.setEncoding("utf-8");
return new Filter[]{filter};
}
}
3.7.删除xml配置文件
3.8.修改web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<welcome-file-list>
<welcome-file>login.jspwelcome-file>
welcome-file-list>
web-app>
3.9.测试
略…
总结
--------------------spring的注解--------------------
1、@PropertySource
作用：加载*.properties，等价于context:property-placeholder/
属性：
value：指定*.properties文件的位置
2、@Bean
作用：把实体bean放到ioc容器里，等于
属性：
value：指定IOC容器的key
3、@ComponentScan
作用：指定spring要扫描的包，等价于
属性：
value：指定要扫描的包
4、@Import
作用：导入配置类，等价于
属性：
value：配置类的字节码
5、@Configuration
作用：等价于，spring读取到该注解会创建一个ioc容器