spring boot学习（八）---统一异常处理

八 统一异常处理

1.内容

统一对异常进行高效的处理

2.添加统一返回报文格式

在entity包下新建Result类

package com.boot.entity;/** * http请求返回的最外层对象 * @author LCJA * @param <T> * */public class Result<T> {    private Integer code;    private String msg;    private T data;    public Integer getCode() {        return code;    }    public void setCode(Integer code) {        this.code = code;    }    public String getMsg() {        return msg;    }    public void setMsg(String msg) {        this.msg = msg;    }    public T getData() {        return data;    }    public void setData(T data) {        this.data = data;    }}

修改StuController下的getAdd方法

@RequestMapping(method=RequestMethod.POST)    public Result<Stu> getAdd(@Valid Stu stu,BindingResult bindresult){        if(bindresult.hasErrors()){            Result result = new Result();            result.setCode(1);            result.setMsg(bindresult.getFieldError().getDefaultMessage());            return result;        }        stu.setAge(stu.getAge());        stu.setName(stu.getName());        stu = stuRepository.save(stu);        Result result = new Result();        result.setCode(0);        result.setMsg("成功");        result.setData(stu);        return result;    }

重新调用该方法后

如果不通过校验

3.添加统一返回方法

在utils下写ResultUtil类

package com.boot.utils;import com.boot.entity.Result;public class ResultUtil {    public static Result success(Object object){        Result result = new Result();        result.setCode(0);        result.setMsg("成功");        result.setData(object);        return result;    }    public static Result success(){        return success(null);    }    public static Result error(Integer code,String message){        Result result = new Result();        result.setCode(code);        result.setMsg(message);        return result;    }}

修改StuController下的getAdd方法

@RequestMapping(method=RequestMethod.POST)    public Result<Stu> getAdd(@Valid Stu stu,BindingResult bindresult){        if(bindresult.hasErrors()){            return ResultUtil.error(1, bindresult.getFieldError().getDefaultMessage());        }        stu.setAge(stu.getAge());        stu.setName(stu.getName());        stu = stuRepository.save(stu);        return ResultUtil.success(stu);    }

数据库插入数据age=11 name=测试

新建handle包，在下新建ExceptionHandle类

package com.boot.handle;import org.springframework.web.bind.annotation.ControllerAdvice;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.ResponseBody;import com.boot.entity.Result;import com.boot.utils.ResultUtil;@ControllerAdvicepublic class ExceptionHandle {    @ExceptionHandler(value = Exception.class)    @ResponseBody    public Result handle(Exception e){        return ResultUtil.error(100, e.getMessage());    }}

4.自定义异常

创建自己的exception
创建exception包，包下建StuException

package com.boot.Exception;public class StuException extends RuntimeException{    private Integer code;    public Integer getCode() {        return code;    }    public void setCode(Integer code) {        this.code = code;    }    public StuException(Integer code,String message) {        super(message);        this.code = code;    }}

在service实现类中getAge中修改

public void getAge(Integer id)  throws Exception{        Stu stu = sturepository.findOne(id);        Integer age = Integer.valueOf(stu.getAge());        if(age < 10 ){            throw new StuException(100,"小于10岁");        }else if( age > 10 && age < 16 ){            throw new StuException(101,"小于16岁");        }    }

修改ExceptionHandle类

package com.boot.handle;import org.springframework.web.bind.annotation.ControllerAdvice;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.ResponseBody;import com.boot.Exception.StuException;import com.boot.entity.Result;import com.boot.utils.ResultUtil;@ControllerAdvicepublic class ExceptionHandle {    @ExceptionHandler(value = Exception.class)    @ResponseBody    public Result handle(Exception e){        if(e instanceof StuException){            StuException stuexception= (StuException) e;            return ResultUtil.error(stuexception.getCode(),stuexception.getMessage());        }        return ResultUtil.error(-1, "未知错误");    }}

5.用枚举表示异常

package com.boot.enums;public enum ResultEnum {    UNKONW_ERROR(-1,"未知错误"),    SUCCESS(0,"成功"),    TEN(100,"小于10岁"),    SIXTEEN(101,"小于16岁")    ;    private Integer code;    private String message;    private ResultEnum(Integer code, String message) {        this.code = code;        this.message = message;    }    public Integer getCode() {        return code;    }    public void setCode(Integer code) {        this.code = code;    }    public String getMessage() {        return message;    }    public void setMessage(String message) {        this.message = message;    }}

在StuException中添加构造函数

public StuException(ResultEnum result) {        super(result.getMessage());        this.code = result.getCode();    }

这样StuServiceImpl中的getAge可以这样写

public void getAge(Integer id)  throws Exception{        Stu stu = sturepository.findOne(id);        Integer age = Integer.valueOf(stu.getAge());        if(age < 10 ){            throw new StuException(ResultEnum.TEN);        }else if( age > 10 && age < 16 ){            throw new StuException(ResultEnum.SIXTEEN);        }    }