ssm——mybatis,mapper.xml不映射Javabean直接返回list

UserMapper.xml:

此处resultType为java.util.HashMap,不需要配置resultMap

		select * from user

UserDao接口：

List> selectAllUser();

UserService接口：

List> selectUser();

UserServiceImp：

public List> selectUser() {
	List> u = userDao.selectAllUser();
	return u;
}

UserController：

@RequestMapping(value="/selectUser")
@ResponseBody
public String selectUser(){
	List> u = userService.selectUser();
	System.out.println(u.toString()); 
    //结果：[{username=1, password=1221}, {username=2, password=1}]
	String jsonString = JSON.toJSONString(u);
	System.out.println(jsonString); 
    //结果：[{"username":"1","password":"1221"},{"username":"2","password":"1"}]
	return jsonString;
}