public class Result{

    private Object data;

    private Integer code;

    private String msg;

}

@SuppressWarnings("all")

public class Code {

    public static final Integer SAVE_OK = 20011;

    public static final Integer DELETE_OK = 20011;

    public static final Integer UPDATE_OK = 20011;

    public static final Integer SELECT_OK = 20011;

    public static final Integer SAVE_ERR = 20010;

    public static final Integer DELETE_ERR = 20010;

    public static final Integer UPDATE_ERR = 20010;

    public static final Integer SELECT_ERR = 20010;

}

@SuppressWarnings("all")

@RestController

@RequestMapping("/books")

public class BookController {

    @Autowired

    private BookService bookService;

    @PostMapping

    public Result save(@RequestBody Book b) {

        boolean save = bookService.save(b);

        return new Result(save ? Code.SAVE_OK:Code.SAVE_ERR,save);

    }

    @PutMapping

    public Result update(@RequestBody Book b) {

        boolean update = bookService.update(b);

        return new Result(update ? Code.UPDATE_OK:Code.UPDATE_ERR,update);

    }

    @DeleteMapping("/{id}")

    public Result delete(@PathVariable Integer id) {

        boolean delete = bookService.delete(id);

        return new Result(delete ? Code.DELETE_OK:Code.DELETE_ERR,delete);

    }

    @GetMapping("/{id}")

    public Result getById(@PathVariable Integer id) {

        Book byId = bookService.getById(id);

        Integer i = byId != null ? Code.SELECT_OK:Code.SELECT_ERR;

        String msg = byId != null ? "查询成功":"查询失败";

        return new Result(i,byId,msg);

    }

    @GetMapping

    public Result getAll() {

        List<Book> all = bookService.getAll();

        Integer i = all != null ? Code.SELECT_OK:Code.SELECT_ERR;

        String msg = all != null ? "查询成功":"查询失败";

        return new Result(i,all,msg);

    }

}

@SuppressWarnings("all")

@RestControllerAdvice

public class ProjectExceptionAdvice {

    @ExceptionHandler(Exception.class)

    public Result doException(Exception e){

        System.out.println("异常:你干嘛~ 嗨嗨呦,啊哈哈~");

        return new Result(666,null,"异常:你干嘛~ 嗨嗨呦,啊哈哈~");

    }

}

@SuppressWarnings("all")

public class SystemException extends RuntimeException{

//    异常编码

    private Integer code;

    public SystemException( Integer code, String message) {

        super(message);

        this.code = code;

    }

    public SystemException(Integer code, String message, Throwable cause) {

        super(message, cause);

        this.code = code;

    }

    public Integer getCode() {

        return code;

    }

    public void setCode(Integer code) {

        this.code = code;

    }

}

@SuppressWarnings("all")

public class BusinessException extends RuntimeException{

//    异常编码

    private Integer code;

    public BusinessException(Integer code, String message) {

        super(message);

        this.code = code;

    }

    public BusinessException(Integer code, String message, Throwable cause) {

        super(message, cause);

        this.code = code;

    }

    public Integer getCode() {

        return code;

    }

    public void setCode(Integer code) {

        this.code = code;

    }

}

@SuppressWarnings("all")

public class Code {

    public static final Integer SYSTEM_ERR = 50011;

    public static final Integer BUSINESS_ERR = 50012;

    public static final Integer SYSTEM_TIMEOUT_ERR = 50013;

    public static final Integer SYSTEM_UNKNO_ERR = 5999;

}

@SuppressWarnings("all")

@Service

public class BookServiceImpl implements BookService {

    @Autowired

    private BookDao bookDao;

    @Override

    public Book getById(Integer id) {

        if(id == 1){

            throw new BusinessException(Code.BUSINESS_ERR,"请输入规范的信息");

        }

//        将可能出现的异常进行包装，转换成自定义异常

        try{

            int i = 1/0;

        }catch(ArithmeticException ex){

            throw new SystemException(Code.SYSTEM_TIMEOUT_ERR,"服务器访问超时，请稍后再试。。。",ex);

        }

        return bookDao.getById(id);

    }

}

@SuppressWarnings("all")

@RestControllerAdvice

public class ProjectExceptionAdvice {

    @ExceptionHandler(Exception.class)

    public Result doException(Exception e){

//        记录日志

//        发送消息给运维

//        发送邮件给开发人员，异常对象发送给开发人员

        return new Result(Code.SYSTEM_UNKNO_ERR,null,"异常:你干嘛~ 嗨嗨呦,啊哈哈~");

    }

    @ExceptionHandler(SystemException.class)

    public Result doSystemException(SystemException e){

//        记录日志

//        发送消息给运维

//        发送邮件给开发人员，异常对象发送给开发人员

        return new Result(e.getCode(),null,e.getMessage());

    }

    @ExceptionHandler(BusinessException.class)

    public Result doBusinessException(BusinessException e){

        return new Result(e.getCode(),null,e.getMessage());

    }

}

package com.atguigu.gulimail.product.exception;

import com.atguigu.common.utils.R;

import lombok.extern.slf4j.Slf4j;

import org.springframework.validation.BindingResult;

import org.springframework.web.bind.MethodArgumentNotValidException;

import org.springframework.web.bind.annotation.ExceptionHandler;

import org.springframework.web.bind.annotation.ResponseBody;

import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.HashMap;

import java.util.Map;

/**

 * 集中处理所有异常

 */

@Slf4j

@RestControllerAdvice(basePackages = "com.atguigu.gulimail.product.controller")

public class GulimallExceptionControllerAdvice

{

    @ResponseBody

    //                        一开始不知道这个错误的异常类是什么先定义 Exception.class

    @ExceptionHandler(value = MethodArgumentNotValidException.class)

    //                        一开始不知道这个错误的异常类是什么先定义 Exception.class

    public R handleValidException(MethodArgumentNotValidException e)

    {   //                                                        这里会打印出异常类我们从控制台复制该上面

        log.error("数据校验出现问题：{},异常类型：{}", e.getMessage(), e.getClass());

        // 实例化 BindingResult 异常对象

        BindingResult bindingResult = e.getBindingResult();

        // 实例化 map 存储所有该异常的信息

        Map<String, String> errorMap = new HashMap<>();

        // 遍历异常

        bindingResult.getFieldErrors().forEach(r -> {

            // 添加异常信息

            errorMap.put(r.getField(), r.getDefaultMessage());

        });

        // 将异常信息返回到前端

        return R.error(400, "数据校验出现异常").put("data", errorMap);

    }

   // 以后可以针对更多的异常来进行不同的处理

   //... 此处省略一百行代码

}