实验报告1--Spring Boot自定义异常处理

实验报告1-Spring Boot自定义异常处理（1）

实验报告1-Spring Boot自定义异常处理（2）

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一、实现思路

实现根据员工id删除员工对象的功能。

要求：1、处理Exception异常。

2、处理自定义的MyException异常。

3、处理404异常。

二、实验步骤

新建maven项目，引入pom依赖，定义SpringBoots入口函数

1、处理Exception异常

（1）新建Employee Controller

controller包，EmployeeController.java

@RestController
@RequestMapping("/employee")
public class EmployeeController {
    @RequestMapping("/deleteOneById/{id}")
    public String deleteOneById(@PathVariable Integer id){
        System.out.println("id = "+id);
        return "OK";
    }
}

（2）定义返回结果包装类Result

util包，Result.java

public class Result<T> {
    private Integer status;//返回状态值
    private String msg;//返回信息
    private T data;//传送的数据
    private static final Integer OK_CODE=200;
    private static final String OK_MSG="SUCCESS";
    private static final Integer ERROR_CODE=0;
    private static final String ERROR_MSG="ERROR";
    public Result(Integer status, String msg, T data) {
        this.status = status;
        this.msg = msg;
        this.data = data;
    }
    public Result(Integer status, String msg) {
        this.status = status;
        this.msg = msg;
    }
    public Result() {
        this(OK_CODE, OK_MSG);
    }
    public static <T> Result<T> success(){
        return new Result<T>();
    }
​
    public static <T> Result<T> success(T result){
        Result<T> response = new Result<T>();
        response.setData(result);
        return response;
    }
    public static <T> Result<T> error() {
        return new Result<T>(ERROR_CODE, ERROR_MSG);
    }
    public static <T> Result<T> error(Integer code, String msg) {
        return new Result<T>(code, msg);
    }
    public void setErrorCode() {
        this.status = ERROR_CODE;
    }
    //Get,Set,ToString方法
}

（3）新建异常处理类

handler包，MyExceptionHandler.java

@ControllerAdvice
public class MyExceptionHandler {
    @ExceptionHandler(Exception.class)
    @ResponseBody
    public Result hanldeException(Exception exception){
        return new Result(0,exception.getMessage());
    }
}

2、处理MyException异常

（1）定义异常信息枚举ErrorEnum

exception包，ErrorEnum.java

public enum ErrorEnum {
    //400系列
    BAD_REQUEST(400,"请求的数据格式不符!"),
    UNAUTHORIZED(401,"登录凭证过期!"),
    FORBIDDEN(403,"抱歉，你无权限访问!"),
    NOT_FOUND(404, "请求的资源找不到!"),
    //500系列
    INTERNAL_SERVER_ERROR(500, "服务器内部错误!"),
    SERVICE_UNAVAILABLE(503,"服务器正忙，请稍后再试!"),
    //未知异常
    UNKNOWN(10000,"未知异常!");
    private Integer code;
    private String message;
    ErrorEnum(Integer code, String message) {
        this.code = code;
        this.message = message;
    }
    public Integer getCode() {
        return code;
    }
    public String getMessage() {
        return message;
    }
}

（2）新建自定义异常类

exception包，MyException.java

public class MyException extends Exception{
    private final Integer code;
    private final String message;
    public MyException(Integer code, String message) {
        this.code = code;
        this.message = message;
    }
    public MyException(ErrorEnum errorEnum) {
        this(errorEnum.getCode(),errorEnum.getMessage());
    }
    public Integer getCode() {
        return code;
    }
    @Override
    public String getMessage() {
        return message;
    }
}

（3）新建异常处理类

handler包，MyExceptionHandler.java

@ControllerAdvice
public class MyExceptionHandler {
    @ExceptionHandler(MyException.class)
    @ResponseBody
    public Result hanldeMyException(MyException myException){
        return new Result(myException.getCode(), myException.getMessage());
    }
}

（4）新建Employee Service

service包，EmployeeService.java

@Service
public class EmployeeService {
    public void deleteOne(Integer id) throws MyException {
        if (id < 1){
            //数据校验失败，抛出自定义异常
            throw new MyException(ErrorEnum.BAD_VERIFY);
        }        
        //执行删除逻辑
    }
}

（5）完善Employee Controller

controller包，EmployeeController.java

@RestController
@RequestMapping("/employee")
public class EmployeeController {
    @Autowired
    private EmployeeService employeeService;
    @RequestMapping("/deleteOne/{id}")
    public Result deleteOne(@PathVariable Integer id) throws MyException {
        Result result = new Result();
        employeeService.deleteOne(id);       
        return result;
    }
}

3、处理404异常

（1）修改配置文件

resources目录，application.yml，启用默认的错误处理页面

# 启用默认的错误处理页面
server:
  error:
    whitelabel:
      enabled: false

（2）新建Employee MyErrorController

controller包，MyErrorController.java，实现ErrorController接口

@Controller
public class MyErrorController implements ErrorController {
    @RequestMapping("/error")
    @ResponseBody
    public String handleError() {
        return "404, 请求的资源不见了";
    }
}