ExceptionHandler配合RestControllerAdvice全局处理异常

Java全局处理异常

引言

对于controller中的代码,为了保证其稳定性,我们总会对每一个controller中的代码进行try-catch，但是由于接口太多,try-catch会显得太冗杂,spring为我们提供了全局处理异常的方式

@ExceptionHandler

@RestControllerAdvice

项目构建

项目结构

相关依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

全局处理异常类

package com.lizi.globalexception.exception;

import com.lizi.globalexception.base.BaseResponse;
import com.lizi.globalexception.enums.HttpCode;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

/**
 * @author lizi
 * @description GlobalExceptionHandler
 * @date 2022/6/7
 */
@RestControllerAdvice
public class GlobalExceptionHandler {
    /**
     * 兜底处理RuntimeException异常
     *
     * @return BaseResponse
     */
    @ExceptionHandler(RuntimeException.class)
    BaseResponse baseHandler() {
        System.out.println("RuntimeException");
        return BaseResponse.fail(HttpCode.SYSTEM_ERROR);
    }

    /**
     * 处理NullPointerException异常
     *
     * @return BaseResponse
     */
    @ExceptionHandler(NullPointerException.class)
     BaseResponse nullHandler() {
        System.out.println("NullPointerException");
        return BaseResponse.fail(HttpCode.NULL_ERROR);
    }

    /**
     * 处理ArithmeticException异常
     *
     * @return BaseResponse
     */
    @ExceptionHandler(ArithmeticException.class)
     BaseResponse arithmeticHandler() {
        System.out.println("ArithmeticException");
        return BaseResponse.fail(HttpCode.ARITHMETIC_ERROR);
    }
}

package com.lizi.globalexception.enums;

/**
 * @author lizi
 * @description HttpCode
 * @date 2022/6/7
 */
public enum HttpCode {
    SUCCESS(200,"成功"),
    NULL_ERROR(414,"空指针异常"),
    ARITHMETIC_ERROR(415,"算数异常"),
    SYSTEM_ERROR(567,"系统异常");

    private int code;
    private String msg;

    HttpCode(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }
}

演示效果

1. 正常请求时
   
   
2. 兜底异常被捕获时
   
   
3. 设定的异常被捕获时
   
   

Tips

在编写测试类时 一直报错

javax.servlet.ServletException: Circular view path [queryBattle]: would dispatch back to the current handler URL [/queryBattle] again.

找了好久才发现问题

此处是因为注解使用是@ControllerAdvice
原因是因为springboot底层还是使用的springmvc不加@ResponseBody或者@RestController
返回的是ModeAndView对象,因而报错