SpringBoot+Mybatis完成商品秒杀项目之用户模块开发（三）

1.使用SpringMVC方式开发用户信息

1.增加controller层、dao层、service层
在service层增加UserModel

public class UserModel {
    private Integer id;
    private String name;
    private Byte gender;
    private Integer age;
    private String telphone;
    private String regisitMode;
    private Integer thirdPartyId;
    private String encrptPassword;
}

UserModel需要增加 用户的密码，其通过userPasswordDOMapper从userPasswordDO得到。。。
2创建UserController

@Controller("user")
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/get")
    @ResponseBody
    public UserModel getUser(@RequestParam(name = "id") Integer id) {
        //调用service服务获取对应id的用户对象并返回给前端
        UserModel userModel = userService.getUserById(id);
        return userModel;
    }
}

3.修改userPasswordDOMapper.xml和.java文件
增加方法 selectByUserId

<select id="selectByUserId" parameterType="java.lang.Integer" resultMap="BaseResultMap">
  select
  <include refid="Base_Column_List" />
  from user_password
  where user_id = #{userId,jdbcType=INTEGER}
</select>

userPasswordDO selectByUserId(Integer UserId);

4.编写UserService

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDOMapper userDOMapper;

    @Autowired
    private userPasswordDOMapper userPasswordDOMapper;

    @Override
    public UserModel getUserById(Integer id) {
        //调用UserDOMapper获取到对应的用户dataobject
        UserDO userDO = userDOMapper.selectByPrimaryKey(id);
        if (userDO == null) {
            return null;
        }

        //通过用户id获取对应的用户加密密码信息
        userPasswordDO userPasswordDO = userPasswordDOMapper.selectByUserId(userDO.getId());

        return convertFromDataObject(userDO, userPasswordDO);
    }

    private UserModel convertFromDataObject(UserDO userDO,userPasswordDO userPasswordDO) {
        if (userDO == null) {
            return null;
        }

        UserModel userModel = new UserModel();
        BeanUtils.copyProperties(userDO, userModel);

        if (userPasswordDO != null) {
            userModel.setEncrptPassword(userPasswordDO.getEncrptPassword());
        }
        return userModel;

    }
}

5.这种方式存在的问题
直接给前端用户返回了UserModel，使得攻击者可以直接看到密码！！！！
解决办法：
需要在controller层增加一个viewobject模型对象只包括以下信息

public class UserVO {
    private Integer id;
    private String name;
    private Byte gender;
    private Integer age;
    private String telphone;
}

6.改造controller

public UserVO getUser(@RequestParam(name = "id") Integer id) {
    //调用service服务获取对应id的用户对象并返回给前端
    UserModel userModel = userService.getUserById(id);

    //将核心领域模型用户对象转化为可供UI使用的viewobject
    return convertFromModel(userModel);
}

private UserVO convertFromModel(UserModel userModel) {
    if (userModel == null) {
        return null;
    }
    UserVO userVO = new UserVO();
    BeanUtils.copyProperties(userModel, userVO);
    return userVO;

}

2.定义通用的返回对象——返回正确信息

之前的程序一旦出错，只会返回一个白页，并没有错误信息，需要返回一个有意义的错误信息
1.增加一个response包。创建CommonReturnType类

public class CommonReturnType {

    //表明对应请求的返回处理结果“success”或“fail”
    private String status;

    //若status=success，则data内返回前端需要的json数据
    //若status=fail，则data内使用通用的错误码格式
    private Object data;

    //定义一个通用的创建方法
    public static CommonReturnType create(Object result) {
        return CommonReturnType.create(result, "success");
    }

    public static CommonReturnType create(Object result,String status) {
        CommonReturnType type = new CommonReturnType();
        type.setStatus(status);
        type.setData(result);
        return type;
    }
}

2.改造返回值

public CommonReturnType getUser(@RequestParam(name = "id") Integer id) {
    //调用service服务获取对应id的用户对象并返回给前端
    UserModel userModel = userService.getUserById(id);

    //将核心领域模型用户对象转化为可供UI使用的viewobject
    UserVO userVO = convertFromModel(userModel);
    
    //返回通用对象
    return CommonReturnType.create(userVO);
}

3 定义通用的返回对象——返回错误信息

1.创建error包

2.创建commonError接口

public interface CommonError {
    public int getErrCode();

    public String getErrMsg();

    public CommonError setErrMsg(String errMs);
}

3.创建实现类EmBussinessError

public enum EmBussinessError implements CommonError {
    //通用错误类型00001
    PARAMETER_VALIDATION_ERROR(00001, "参数不合法"),


    //10000开头为用户信息相关错误定义
    USER_NOT_EXIST(10001, "用户不存在")
    ;

    private EmBussinessError(int errCode, String errMsg) {
        this.errCode = errCode;
        this.errMsg = errMsg;
    }

    private int errCode;
    private String errMsg;

    @Override
    public int getErrCode() {
        return this.errCode;
    }

    @Override
    public String getErrMsg() {
        return this.errMsg;
    }

    @Override
    public CommonError setErrMsg(String errMsg) {
        this.errMsg = errMsg;
        return this;
    }
}

4.包装器模式实现BussinessException类

//包装器业务异常实现
public class BussinessException extends Exception implements CommonError {

    private CommonError commonError;

    //直接接受EmBusinessError的传参用于构造业务异常
    public BussinessException(CommonError commonError) {
        super();
        this.commonError = commonError;
    }

    //接收自定义errMsg的方式构造业务异常
    public BussinessException(CommonError commonError, String errMsg) {
        super();
        this.commonError = commonError;
        this.commonError.setErrMsg(errMsg);
    }

    @Override
    public int getErrCode() {
        return this.commonError.getErrCode();
    }

    @Override
    public String getErrMsg() {
        return this.commonError.getErrMsg();
    }

    @Override
    public CommonError setErrMsg(String errMsg) {
        this.commonError.setErrMsg(errMsg);
        return this;
    }
}

5.抛出异常类

public CommonReturnType getUser(@RequestParam(name = "id") Integer id) throws BusinessException {
    //调用service服务获取对应id的用户对象并返回给前端
    UserModel userModel = userService.getUserById(id);

    //若获取的对应用户信息不存在
    if (userModel == null) {
        throw new BussinessException(EmBussinessError.USER_NOT_EXIST);
    }
    //将核心领域模型用户对象转化为可供UI使用的viewobject
    UserVO userVO = convertFromModel(userModel);

    //返回通用对象
    return CommonReturnType.create(userVO);
}

3 定义通用的返回对象——异常处理

1.定义exceptionHandler解决未被controller层吸收的exception

public class BaseController {

    //定义exceptionHandler解决未被controller层吸收的exception
    @ExceptionHandler(Exception.class)
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    public Object handlerException(HttpServletRequest request, Exception ex) {
        Map<String, Object> responseData = new HashMap<>();
        if (ex instanceof BussinessException) {
            BussinessException bussinessException = (BusinessException) ex;
            responseData.put("errCode", bussinessException.getErrCode());
            responseData.put("errMsg", bussinessException.getErrMsg());
        } else {
            responseData.put("errCode", EmBussinessError.UNKNOWN_ERROR.getErrCode());
            responseData.put("errMsg", EmBussinessError.UNKNOWN_ERROR.getErrMsg());
        }
        return CommonReturnType.create(responseData, "fail");
    }

}

测试：