bean管理的注解方式

（一）使用注解定义bean

（1）常用注解

 

（2）实例

1.在pom.xml中进行配置

       
          
       
        org.springframework
           
       
        spring-jdbc
           
       
        5.1.5.RELEASE
         
        
          
       
        org.springframework
           
       
        spring-context
           
       
        5.1.5.RELEASE
         
        
          
       
        org.springframework
           
       
        spring-aop
           
       
        5.1.5.RELEASE
         
        
          
       
        org.springframework
           
       
        spring-core
           
       
        5.1.5.RELEASE
         
        
          
       
        org.springframework
           
       
        spring-beans
           
       
        5.1.5.RELEASE
         
        
          
       
        org.springframework
           
       
        spring-tx
           
       
        5.1.5.RELEASE
         
        
          
       
        junit
           
       
        junit
           
       
        4.11
         
      
     

 

2.创建一个类，在类中写一个方法，在类上加一个注解@Component

package service;import org.junit.Test;import org.springframework.stereotype.Component;import sun.misc.Contended;@Component("UserService")public class UserService {    public String Hello(){        return "hello";    }}

 

3.创建一个applicationContext.xml，在里面配置包扫描

 

4.创建一个log4j.properties

### direct log messages to stdout ###log4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.Target=System.errlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n### direct messages to file mylog.log ###log4j.appender.file=org.apache.log4j.FileAppenderlog4j.appender.file.File=c\:mylog.loglog4j.appender.file.layout=org.apache.log4j.PatternLayoutlog4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n### set log levels - for more verbose logging change 'info' to 'debug' ###log4j.rootLogger=info, stdout

 

5.创建一个测试类

package test;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import service.UserService;public class UserTest {    @Test    public void hellotest(){        ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");        UserService userService=(UserService)applicationContext.getBean("UserService");        String s=userService.Hello();        System.out.println(s);    }}

 

（二）属性注入的注解

（1）常用注解

 

 

1.属性注入

package service;import org.junit.Test;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Component;import sun.misc.Contended;@Component("UserService")public class UserService {    @Value("小欢")    private String name;    public String Hello(){        return "hello"+name;    }}

 

2.类注入

（a）UserService.java

package service;import dao.UserDao;import org.junit.Test;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Component;import sun.misc.Contended;import javax.annotation.Resource;@Component("UserService")public class UserService {    @Value("小欢")    private String name;    @Resource(name="UserDao")    private UserDao userDao;    public String Hello(){        System.out.println("service中的hello");        return "hello"+name;    }}

 

（b）UserDao.java

package dao;import org.springframework.stereotype.Repository;@Repository("UserDao")public class UserDao {    public void Hello(){        System.out.println("dao 中的hello");    }}

 

（c）applicationContext.xml

 

（d）UserTest.java

package test;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import service.UserService;public class UserTest {    @Test    public void hellotest(){        ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");        UserService userService=(UserService)applicationContext.getBean("UserService");        String s=userService.Hello();        System.out.println(s);    }}

 

（三）其他注解

 

 

 

（四）xml和注解整合开发

1.UserService2.java

package service;import dao.UserDao2;import org.springframework.stereotype.Repository;import javax.annotation.Resource;public class UserService2 {    @Resource(name="UserDao2")    private UserDao2 userDao2;    public void He(){        userDao2.He();        System.out.println("userservice2中的he");    }}

 

2.UserDao2.java

package dao;public class UserDao2 {    public void He(){        System.out.println("userdao2中的he");    }}

 

3.applicationContext.xml

 

4.UserTest.java

package test;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import service.UserService;import service.UserService2;public class UserTest {    @Test    public void hetest(){        ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");        UserService2 userService2=(UserService2)applicationContext.getBean("UserService2");        userService2.He();    }}