Spring IoC — 基于注解的配置

基于XML的配置，Bean定义信息和Bean实现类本身是分离的，而采用基于注解的配置方式时，Bean定义信息即通过在Bean实现类上标注注解实现。

@Component：对类进行标注，Spring容器自动将POJO转换为容器管理的Bean； @Repository：用于对DAO实现类进行标注； @Service：用于对Service实现类进行标注； @Controller：用于对Controller实现类进行标注。 1、自动装配Bean： beans.xml： <?xml version="1.0" encoding="UTF-8" ?> <beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-3.0.xsd"><context:component-scan base-package="com.ioc.ch4_10"/><bean id="ls" class="com.ioc.ch4_10.LogonService"></bean><!-- context:component-scan base-package="com.baobaotao" resource-pattern="anno/*.class"/ --><!-- context:component-scan base-package="com.baobaotao"><context:include-filter type="regex" expression="com\.baobaotao\.anno.*Dao"/><context:include-filter type="regex" expression="com\.baobaotao\.anno.*Service"/><context:exclude-filter type="aspectj" expression="com.baobaotao..*Controller+"/></context:component-scan --> </beans>

 LogDao类：

package com.ioc.ch4_10; import org.springframework.stereotype.Component; @Component("logDao") public class LogDao { }

UserDao_1类：

package com.ioc.ch4_10; import org.springframework.stereotype.Component; @Component("userDao_1") //自动被Spring容器识别，Spring容器自动将POJO转换为容器管理的Bean //等价于XML配置的<bean id="userDao_1" class="com.ioc.ch4_10.UserDao_1"> public class UserDao_1 {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "UserDao_1{" +"name='" + name + '\t' +'}';}public UserDao_1() {System.out.println("userDao");} }

UserDao_2类：

package com.ioc.ch4_10; import org.springframework.stereotype.Component; /*** Created by gao on 16-3-25.*/ @Component("userDao_2") public class UserDao_2 {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "UserDao_2{" +"name='" + name + '\t' +'}';}public UserDao_2() {System.out.println("userDao_2");} }

UserDao_3类：

package com.ioc.ch4_10; import org.springframework.stereotype.Component; /*** Created by gao on 16-3-25.*/ @Component("userDao_3") public class UserDao_3 {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "UserDao_3{" +"name='" + name + '\t' +'}';}public UserDao_3() {System.out.println("userDao_3");} }

LogonService类：

package com.ioc.ch4_10; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Service; @Service public class LogonService{//使用@Autowired进行自动注入 @Autowiredprivate LogDao logDao;@Autowiredprivate UserDao_1 userDao1;//使用@Autowired的required属性，设置为false表示找不到匹配的Bean完成注入也不要抛出异常@Autowired(required = false)private UserDao_2 userDao_2;//使用@Qualifier指定注入Bean的名称 @Autowired@Qualifier("userDao_3")private UserDao_3 userDao_3;public LogDao getLogDao() {return logDao;}public UserDao_1 getUserDao1() {return userDao1;}public UserDao_2 getUserDao2() {return userDao_2;}public UserDao_3 getUserDao3() {return userDao_3;}public void printSomething(){userDao1.setName("LogonService-userDao1");System.out.println(userDao1.toString());userDao_2.setName("LogonService-userDao2");System.out.println(userDao_2.toString());userDao_3.setName("LogonService-userDao3");System.out.println(userDao_3.toString());} }

LoginService_2类：

package com.ioc.ch4_10; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Service; /*** Created by gao on 16-3-25.*/ @Service public class LogonService_2 {private LogDao logDao;private UserDao_1 userDao_1;//自动将LogDao传给方法入参 @Autowiredpublic void setLogDao(LogDao logDao) {System.out.println("auto setlogdao");this.logDao = logDao;}//自动将名为userDao的Bean传给方法入参 @Autowiredpublic void setUserDao_1(UserDao_1 userDao_1) {System.out.println("auto setuserdao");this.userDao_1 = userDao_1;}@Autowiredpublic void init(@Qualifier("userDao_1")UserDao_1 userDao,LogDao logDao){System.out.println("multi param inject");this.userDao_1 = userDao;this.logDao =logDao;} }

测试类：

package com.ioc.ch4_10; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /*** Created by gao on 16-3-25.*/ public class Test {public static void main(String[] args) {ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath:com\\ioc\\ch4_10\\beans.xml");LogonService ls = (LogonService) ctx.getBean("ls");ls.printSomething();} }

 

输出结果： userDao userDao_2 userDao_3 multi param inject auto setlogdao auto setuserdao UserDao_1{name='LogonService??userDao1} UserDao_2{name='LogonService-userDao2 } UserDao_3{name='LogonService-userDao3 } 2、对集合类进行标注 Plugin接口： package com.ioc.ch4_10; public interface Plugin { }

 onePlugin类：

package com.ioc.ch4_10; import org.springframework.stereotype.Component; @Component public class OnePlugin implements Plugin { }

twoPlugin类：

package com.ioc.ch4_10; import org.springframework.stereotype.Component; @Component public class TwoPlugin implements Plugin { }

MyComponent类：

package com.ioc.ch4_10; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import java.util.List; @Component public class MyComponent {//Spring会将容器中所有类型为Plugin的Bean注入到这个变量中@Autowired(required=false)private List<Plugin> plugins;public List<Plugin> getPlugins() {return plugins;} }

mycomponent.xml：

<?xml version="1.0" encoding="UTF-8" ?> <beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-3.0.xsd"><context:component-scan base-package="com.ioc.ch4_10"><context:include-filter type="aspectj" expression="com.baobaotao.anno.*Plugin+"/><context:include-filter type="aspectj" expression="com.baobaotao.anno.MyComponent"/></context:component-scan> </beans>

MyComponentTest类：

package com.ioc.ch4_10; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class MyComponentTest {public static void main(String[] args) throws Throwable {ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath:com\\ioc\\ch4_10\\mycomponent.xml");MyComponent myComponent = ctx.getBean(MyComponent.class);System.out.println("pulgin.size:"+myComponent.getPlugins().size());} } 输出结果： userDao userDao_2 userDao_3 multi param inject auto setlogdao auto setuserdao pulgin.size:2 3、Bean作用范围及生命过程方法 使用Scope指定作用范围 package com.ioc.ch4_10; import org.springframework.beans.factory.config.BeanDefinition; import org.springframework.context.annotation.Scope; import org.springframework.stereotype.Component; //指定Bean的作用范围为prototype @Scope(BeanDefinition.SCOPE_PROTOTYPE) @Component public class Car {private int maxSpeed;public String brand;private double price;...... }

 

 Boss类：

package com.ioc.ch4_10; import org.springframework.stereotype.Component; import javax.annotation.PostConstruct; import javax.annotation.PreDestroy; import javax.annotation.Resource; @Component public class Boss {private Car car;public Boss(){System.out.println("construct...");}@Resourceprivate void setCar(Car car){System.out.println("execute in setCar");this.car = car;}@PostConstructprivate void init1(){System.out.println("execute in init1");}@PostConstructprivate void init2(){System.out.println("execute in init1");}@PreDestroyprivate void destory1(){System.out.println("execute in destory1");}@PreDestroyprivate void destory2(){System.out.println("execute in destory2");} }

测试类：

package com.ioc.ch4_10; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /*** Created by gao on 16-3-25.*/ public class Test {public static void main(String[] args) {ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath:com\\ioc\\ch4_10\\beans.xml");Car car1 = (Car) ctx.getBean("car");Car car2 = (Car) ctx.getBean("car");System.out.println(car1 == car2); //falseUserDao_2 ud1 = (UserDao_2) ctx.getBean("userDao_2");UserDao_2 ud2 = (UserDao_2) ctx.getBean("userDao_2");System.out.println(ud1 == ud2); //true ((ClassPathXmlApplicationContext)ctx).destroy();} } 输出结果： construct... execute in setCar execute in init1 execute in init1 false true execute in destory2 execute in destory1

 

 

 

 

 

 

 

 

 

 

 

转载于:https://www.cnblogs.com/yangyquin/p/5321373.html

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