SpringBoot的@RestControllerAdvice定义全局异常处理

通常情况下，业务层抛出一些业务异常，controller层不能直接将异常堆栈信息返回给页面，而是将异常信息封装起来，将有用的信息提示出来，全局异常处理器就可以做这件事情。

@RestControllerAdvice：@ControllerAdvice和@ResponseBody的组合，捕捉 @Controller 和 @RestController 抛出的异常。

环境准备

1.创建springboot项目

2.引入依赖：

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

定义统一的响应对象

Result：

code：标识请求成功/请求失败

data：存放响应数据

message：存放响应提示信息

info：附加信息

requestId：traceId

import java.io.Serializable;
​
/**
 * @author kerwin
 * @date 2021/7/22  18:07
 */
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//
​
public class Result<T> implements Serializable {
    private static final long serialVersionUID = 1L;
    public static final transient String DEFAULT_SUCCESS_CODE = "0";
    public static final transient String DEFAULT_ERROR_CODE = "-1";
    private String code;
    private T data;
    private String message;
    private String info;
    private String requestId;
​
    public Result(T data) {
        this.data = data;
        this.code = "0";
        this.message = "success";
    }
​
    public Result() {
        this.code = "-1";
        this.message = "failure";
    }
​
    public boolean isSuccess() {
        return "0".equals(this.code);
    }
​
    public static Result success() {
        return new Result((Object)null);
    }
​
    public static Result success(Object data) {
        return new Result(data);
    }
​
    public static Result DefaultFailure(String msg) {
        Result result = new Result();
        result.setCode("-1");
        result.setMessage(msg);
        return result;
    }
​
    public String getCode() {
        return this.code;
    }
​
    public T getData() {
        return this.data;
    }
​
    public String getMessage() {
        return this.message;
    }
​
    public String getInfo() {
        return this.info;
    }
​
    public String getRequestId() {
        return this.requestId;
    }
​
    public Result<T> setCode(final String code) {
        this.code = code;
        return this;
    }
​
    public Result<T> setData(final T data) {
        this.data = data;
        return this;
    }
​
    public Result<T> setMessage(final String message) {
        this.message = message;
        return this;
    }
​
    public Result<T> setInfo(final String info) {
        this.info = info;
        return this;
    }
​
    public Result<T> setRequestId(final String requestId) {
        this.requestId = requestId;
        return this;
    }
​
    @Override
    public boolean equals(final Object o) {
        if (o == this) {
            return true;
        } else if (!(o instanceof Result)) {
            return false;
        } else {
            Result<?> other = (Result)o;
            if (!other.canEqual(this)) {
                return false;
            } else {
                label71: {
                    Object this$code = this.getCode();
                    Object other$code = other.getCode();
                    if (this$code == null) {
                        if (other$code == null) {
                            break label71;
                        }
                    } else if (this$code.equals(other$code)) {
                        break label71;
                    }
​
                    return false;
                }
​
                Object this$data = this.getData();
                Object other$data = other.getData();
                if (this$data == null) {
                    if (other$data != null) {
                        return false;
                    }
                } else if (!this$data.equals(other$data)) {
                    return false;
                }
​
                label57: {
                    Object this$message = this.getMessage();
                    Object other$message = other.getMessage();
                    if (this$message == null) {
                        if (other$message == null) {
                            break label57;
                        }
                    } else if (this$message.equals(other$message)) {
                        break label57;
                    }
​
                    return false;
                }
​
                Object this$info = this.getInfo();
                Object other$info = other.getInfo();
                if (this$info == null) {
                    if (other$info != null) {
                        return false;
                    }
                } else if (!this$info.equals(other$info)) {
                    return false;
                }
​
                Object this$requestId = this.getRequestId();
                Object other$requestId = other.getRequestId();
                if (this$requestId == null) {
                    if (other$requestId == null) {
                        return true;
                    }
                } else if (this$requestId.equals(other$requestId)) {
                    return true;
                }
​
                return false;
            }
        }
    }
​
    protected boolean canEqual(final Object other) {
        return other instanceof Result;
    }
​
    @Override
    public int hashCode() {
        boolean PRIME = true;
        int result = 1;
        Object $code = this.getCode();
        result = 0;
        result = result * 59 + ($code == null ? 43 : $code.hashCode());
        Object $data = this.getData();
        result = result * 59 + ($data == null ? 43 : $data.hashCode());
        Object $message = this.getMessage();
        result = result * 59 + ($message == null ? 43 : $message.hashCode());
        Object $info = this.getInfo();
        result = result * 59 + ($info == null ? 43 : $info.hashCode());
        Object $requestId = this.getRequestId();
        result = result * 59 + ($requestId == null ? 43 : $requestId.hashCode());
        return result;
    }
​
    @Override
    public String toString() {
        return "Result(code=" + this.getCode() + ", data=" + this.getData() + ", message=" + this.getMessage() + ", info=" + this.getInfo() + ", requestId=" + this.getRequestId() + ")";
    }
}

定义异常场景，例如业务异常、转换异常等

public class BusinessException extends RuntimeException {
    /**
     *
     */
    private static final long serialVersionUID = -2375722139644724409L;
​
    public BusinessException() {
    }
​
    public BusinessException(String message, Throwable cause) {
        super(message, cause);
    }
​
    public BusinessException(String message) {
        super(message);
    }
​
    public BusinessException(Throwable cause) {
        super(cause);
    }
}
​

定义异常处理控制器

@RestControllerAdvice()  
@Slf4j
@Order(Ordered.HIGHEST_PRECEDENCE)  //加载优先级
@SuppressWarnings("all")
public class ExceptionHandlerController {
    @ExceptionHandler({BusinessException.class})
    @ResponseBody
    public Result<String> businessExceptionHandler(HttpServletRequest req, BusinessException e) throws Exception {
        Result<String> error = new Result<>();
        error.setCode(Result.DEFAULT_ERROR_CODE);
        error.setMessage(e.getMessage());
        error.setRequestId(MDC.get("traceId"));
        return error;
    }
​
    /**
     * 统一处理系统异常, json 格式返回
     *
     * @param t
     *            系统异常
     * @return 带错误码和描述的 json
     */
    @ExceptionHandler(Throwable.class)
    public Result<Void> handleThrowable(Throwable t, HttpServletRequest request) {
        log.error(("handleThrowable requestUri " + request.getRequestURI() + "system error"), t);
        return new Result<Void>().setMessage("系统繁忙，请稍后再试").setInfo("系统繁忙，请稍后再试");
    }
}
​

 测试

/**
 * @author kerwin
 * @date 2021/7/22  22:11
 */
@RestController
public class Test {

    @GetMapping("test/{name}")
    public Result<Void> test(@PathVariable("name") String name){
        //模拟service抛出异常
        throw new BusinessException("fail");
    }
}

请求此接口，返回响应:

符合预期，一个简单的异常处理器就完成啦。