Spring-IOC实现【02-XML配置方式案例】

public interface IUserDao {
  public String add();
}

public class UserDaoImpl implements IUserDao {
  @Override
  public String add() {
    // TODO Auto-generated method stub
    return "hello ... ";
  }
}

public interface IUserService {
  public String add();
}

public class UserServiceImpl implements IUserService {
  private IUserDao dao; 
  // 设值注入 必须的方法
  public void setDao(IUserDao dao) {
    this.dao = dao;
  }
  @Override
  public String add() {
    return dao.add();
  }
}

/**
 * 控制层
 * @author dpb
 *
 */
public class UserController {
  private IUserService service;
  // 设值注入必须的方法
  public void setService(IUserService service) {
    this.service = service;
  }
  public String add(){
    return service.add();
  }
}

<!-- 配置 dao -->
<bean class="com.sxt.dao.impl.UserDaoImpl" id="userDaoImpl"/>
<!-- 配置 service -->
<bean class="com.sxt.service.impl.UserServiceImpl" id="userServiceImpl">
  <!-- 设值注入 dao对象 -->
  <property name="dao" ref="userDaoImpl"></property>
</bean>
<!-- 配置controller -->
<bean class="com.sxt.controller.UserController">
  <!-- 设值注入service对象 -->
  <property name="service" ref="userServiceImpl"></property>
</bean>

@Test
public void test2() {
  // 获取ApplicationContext对象 加载配置文件 反射+xml解析
  ApplicationContext ac = new ClassPathXmlApplicationContext("application.xml");
  UserController bean = ac.getBean(UserController.class);
  System.out.println(bean.add());
}