@RestControllerAdvice异常处理

• 创建一个maven项目

• 编辑pom文件, 引入springboot父依赖以及web依赖

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>SpringAdviceController</artifactId>
<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

• 编写启动类

package cn.zack;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class AdviceApplication {
    public static void main(String[] args) {
        SpringApplication.run(AdviceApplication.class, args);
    }
}

• 自定义异常类

package cn.zack.config;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
/**
 * 自定义异常类
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class MyException extends RuntimeException {
    private long code;
    private String msg;
}

• 自定义全局异常处理器

package cn.zack.config;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;
import java.util.HashMap;
import java.util.Map;
/**
 * 捕捉全局异常
 * 通过@RestControllerAdvice对自定义异常MyException进行包装
 */
@RestControllerAdvice
public class MyExceptionHandler {
    // 以json格式返回
    @ResponseBody
    // 捕获MyException类型的异常
    @ExceptionHandler(MyException.class)
    // 自定义浏览器返回状态码
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public Map myExceptionHandler(MyException myException) {
        HashMap<Object, Object> map = new HashMap<>();
        map.put("code", myException.getCode());
        map.put("msg", myException.getMsg());
        return map;
    }
}

• 编写controller,抛出自定义异常进行测试

package cn.zack.controller;

import cn.zack.config.MyException;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.util.ArrayList;

@RestController
@RequestMapping(path = "/test")
public class MyController {
    @GetMapping(path = "/fun1")
    public String fun1(@RequestParam("param1") int param1){
        try {
            int a = 4 / param1;
            return "OK";
        } catch (Exception e) {
            throw new MyException(500L, e.getMessage());
        }
    }

    @GetMapping(path = "/fun2")
    public String fun2(){
        try {
            ArrayList<String> arrayList = new ArrayList<>();
            return arrayList.get(1);
        } catch (Exception e) {
            throw new MyException(500L, e.getMessage());
        }
    }
}

• 启动应用

调用fun1方法,传入param1=0,制造一个除零异常,可以得到响应报文:
{"msg":"/ by zero","code":500}
调用fun1方法,传入param1=1,得到正常报文:
OK
调用fun2方法,发生空指针异常,得到响应报文:
{"msg":"Index: 1, Size: 0","code":500}