Spring的Java配置方式(无xml)

Spring在4.x版本后支持用java的方式配置,今天要写的是有关Spring的Java配置的Demo.

测试环境:

 1.Windows 7 旗舰版 Service Pack 1

 2.Eclipse Oxygen.1a Release (4.7.1a)

1.新建一个meavn项目,war包工程,如果pom.xml里的war报错,工程中缺少了web.xml文件,项目名称-->右键-->Java EE Tools-->generate deployment descriptor stub.即可解决.

pom.xml

  
  4.0.0
  
  com.warpfuture
  springboot
  0.0.1-SNAPSHOT
  war
  
  
		
			org.springframework
			spring-webmvc
			4.3.7.RELEASE
		
		
		
		    junit
		    junit
		    4.9
		    test
		  
	
	
		
			
			
				org.apache.maven.plugins
				maven-resources-plugin
				
					UTF-8
				
			
			
			
				org.apache.maven.plugins
				maven-compiler-plugin
				
					1.8
					1.8
					UTF-8
				
			
		
	

2.新建SpringConfig.java配置类,以及User.java,  UserDao.java,  UserService.java以及测试类UserTest.java

SpringConfig.java

package com.warpfuture.springboot.javaconfig;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

/**Spring的java配置方式
 * @author JMX
 *
 */
@Configuration //通过该注解来表明该类是一个Spring的配置，相当于一个xml文件
@ComponentScan(basePackages = "com.warpfuture.springboot.javaconfig") //配置扫描包
public class SpringConfig {
    
    @Bean // 通过该注解来表明是一个Bean对象，相当于xml中的
    public UserDAO getUserDAO(){
        return new UserDAO(); // 直接new对象做演示
    }
    
}

User.java

package com.warpfuture.springboot.javaconfig;

/** User对象
 * @author JMX
 *
 */
public class User {
    
    private String username;

    private String password;

    private Integer age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

}

UserDao.java

package com.warpfuture.springboot.javaconfig;

import java.util.ArrayList;
import java.util.List;

/**模拟数据库查询
 * @author JMX
 *
 */
public class UserDAO {
    
    public List queryUserList(){
        List result = new ArrayList();
        // 模拟数据库的查询
        for (int i = 0; i < 5; i++) {
            User user = new User();
            user.setUsername("username=" + i);
            user.setPassword("password=" + i);
            user.setAge(i + 1);
            result.add(user);
        }
        return result;
    }

}

UserService.java

package com.warpfuture.springboot.javaconfig;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**模拟Service层
 * @author JMX
 *
 */
@Service
public class UserService {

    @Autowired // 注入Spring容器中的bean对象
    private UserDAO userDAO;

    public List queryUserList() {
        // 调用userDAO中的方法进行查询
        return this.userDAO.queryUserList();
    }

}

UserTest.java

package com.warpfuture.springboot.test;

import java.util.List;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import com.warpfuture.springboot.javaconfig.SpringConfig;
import com.warpfuture.springboot.javaconfig.User;
import com.warpfuture.springboot.javaconfig.UserService;

public class UserTest {
    	private AnnotationConfigApplicationContext context=null;
    	private UserService userService=null;
    
    	@Before
        public void before() {
    	  // 通过Java配置来实例化Spring容器
             context= new AnnotationConfigApplicationContext(SpringConfig.class);
            
            // 在Spring容器中获取Bean对象
             userService= context.getBean(UserService.class);
            
        }
    	
    	@Test
    	public void test() {
    	     List list = userService.queryUserList();
    	        for (User user : list) {
    	            System.out.println(user.getUsername() + ", " + user.getPassword() + ", " + " age="+user.getAge());
    	        }
    	}
    
    	@After
    	public void after() {
    	    context.destroy();
    	}

}

3.运行测试类UserTest.java里的test()方法,控制台打印

完美测试通过

项目Demo:点击打开链接