SpringBoot学习笔记（六）：全局异常处理

SpringBoot可以使用@ControllerAdvice注解进行全局异常的处理，这样可以方便统一对异常的处理返回

1.处理常见异常

首先我们需要确定一个异常处理统一返回的格式

@Data
public class BaseResult {
    /**
     * 返回code,成功为0，失败为-1
     */
    private String code;

    /**
     * 返回数据
     */
    private Object data;

    /**
     * 返回信息
     */
    private String msg;

    public BaseResult(){

    }

    public BaseResult(String code, Object data, String msg) {
        this.code = code;
        this.data = data;
        this.msg = msg;
    }

    public BaseResult success(Object data, String msg) {
        return new BaseResult("0", data, msg);
    }

    public BaseResult failed(String msg) {
        return new BaseResult("-1", null, msg);
    }
}

接着定义一个全局异常处理类，这里以空指针异常为目标进行处理返回

@ControllerAdvice
@ResponseBody
public class BaseExceptionHandler {

    @ExceptionHandler(NullPointerException.class)
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public BaseResult handleNullException(NullPointerException e){
        return new BaseResult().failed("空指针异常");
    }
}

测试请求

@RestController
public class TestController {

    @GetMapping("/test")
    public String test() {
        String s = null;
        s.toString();
        return "test";
    }
}

2.处理自定义异常

除了一些常见异常的处理，我们还可以自定义一些业务异常

public class BusinessException extends RuntimeException{
    /**
     *  自定义项目内异常
     */
    public BusinessException(String msg){
        super(msg);
    }
}

在全局异常处理类里添加对自定义异常的处理

@ExceptionHandler(BusinessException.class)
@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
public BaseResult handleBusinessException(BusinessException e){
    return new BaseResult().failed(e.getMessage());
}

测试请求

@GetMapping("/test2")
public String test2() {
    try {
        int i = 1 / 0;
    } catch (Exception e) {
        throw new BusinessException("测试自定义异常");
    }
    return "test2";
}

/ 0;
} catch (Exception e) {
throw new BusinessException(“测试自定义异常”);
}
return “test2”;
}

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