1. 添加maven依赖
2. 创建自定义异常类
3. 创建全局捕获异常
4. 使用自定义异常类

maven文件:

        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--shiro-->
        <dependency>
            <groupId>org.apache.shiro</groupId>
            <artifactId>shiro-web</artifactId>
            <version>1.5.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.shiro</groupId>
            <artifactId>shiro-spring</artifactId>
            <version>1.5.3</version>
        </dependency>

创建自定义异常:

package com.resume.uniapp.util.exception;


public class EmosException extends RuntimeException {
    private String msg;
    private int code = 500;

    public EmosException(String msg) {
        super(msg);
        this.msg = msg;
    }

    public EmosException(String msg, Throwable e) {
        super(msg, e);
        this.msg = msg;
    }

    public EmosException(String msg, int code) {
        super(msg);
        this.msg = msg;
        this.code = code;
    }

    public EmosException(String msg, int code, Throwable e) {
        super(msg, e);
        this.msg = msg;
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }
}

创建全局捕获异常:

package com.resume.uniapp.util;

import com.resume.uniapp.util.exception.EmosException;
import lombok.extern.slf4j.Slf4j;
import org.apache.shiro.authz.UnauthorizedException;
import org.springframework.http.HttpStatus;
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.ResponseStatus;
import org.springframework.web.bind.annotation.RestControllerAdvice;

@Slf4j
@RestControllerAdvice
public class ExceptionAdvice {
    @ResponseBody
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    @ExceptionHandler(Exception.class)
    public String exceptionHandler(Exception e){
        log.error("执行异常",e);
        if(e instanceof MethodArgumentNotValidException){
            MethodArgumentNotValidException exception= (MethodArgumentNotValidException) e;
            return exception.getBindingResult().getFieldError().getDefaultMessage();
        }
        else if(e instanceof EmosException) {
            EmosException exception = (EmosException) e;
            return exception.getMsg();
        }
        else if (e instanceof IllegalStateException){
            return "数据类型不正确";
        }
        else if(e instanceof UnauthorizedException){
            return "你不具备相关权限";
        }
        else{
            return "后端执行异常";
        }
    }
}

Service层使用异常类:

public int register(UserInfo req){
        try {
            userMapper.register(req);
        }catch(BindingException e){
            throw new EmosException("返回为空");
        }

        return userMapper.register(req);
    }

注意⚠️:

如果没有写:

throw new EmosException("返回为空");

那么会自动执行全局捕获异常