在现代Web开发中,异常处理是一个不可或缺的部分。良好的异常处理不仅能提高系统的健壮性,还能提升用户体验。在Spring Boot中,全局异常处理的实现可以通过使用@RestControllerAdvice
注解来完成。本文将详细介绍如何使用@RestControllerAdvice
和@ExceptionHandler
来统一处理异常,并给出具体的实现示例。
1. @RestControllerAdvice
概述
@RestControllerAdvice
是Spring MVC提供的一个功能强大的注解,用于全局处理控制器中的异常。它相当于@ControllerAdvice
和@ResponseBody
的组合,可以用于定义以下三种功能:
@ExceptionHandler
:处理特定的异常,并将响应返回给前端。@InitBinder
:预处理Web请求数据的绑定。@ModelAttribute
:将数据绑定到模型中,以便在控制器的@RequestMapping
方法中使用。
@RestControllerAdvice
自动被Spring的组件扫描机制检测到,若应用通过MVC命令空间或MVC Java编程方式配置,该功能默认自动开启。
2. 实现全局异常处理
在实现全局异常处理时,我们通常会定义一个异常处理类,这个类中包含多个异常处理方法,每个方法对应一种或多种异常类型。下面是一个典型的实现示例。
2.1 全局异常处理器
import com.sugon.cloud.lowcode.result.ReturnResult;
import lombok.extern.slf4j.Slf4j;
import org.mybatis.spring.MyBatisSystemException;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import javax.naming.AuthenticationException;
import javax.servlet.http.HttpServletRequest;
import static com.sugon.cloud.lowcode.constants.SplitCharacter.LEFT_PARENTHESES;
import static com.sugon.cloud.lowcode.constants.SplitCharacter.RIGHT_PARENTHESES;
import static com.sugon.cloud.lowcode.result.CodeMessageEnum.*;
@RestControllerAdvice
@Slf4j
public class GlobalExceptionHandler {
@ExceptionHandler(value = BizException.class)
@ResponseBody
public ReturnResult bizExceptionHandler(HttpServletRequest req, BizException e) {
log.error("发生业务异常: {}, 请求接口: {}", e.getMessage(), req.getRequestURI());
return ReturnResult.error(e.getCode(), e.getMessage());
}
@ExceptionHandler(value = NullPointerException.class)
@ResponseBody
public ReturnResult exceptionHandler(HttpServletRequest req, NullPointerException e) {
log.error("空指针异常信息: {}, 请求接口: {}", e, req.getRequestURI());
return ReturnResult.error(
NULL_POINT_ERROR_EXCEPTION.getCode(),
NULL_POINT_ERROR_EXCEPTION.getMessage()
+ RIGHT_PARENTHESES
+ e.getMessage()
+ LEFT_PARENTHESES);
}
@ExceptionHandler(value = HttpRequestMethodNotSupportedException.class)
@ResponseBody
public ReturnResult methodNotSupportedExceptionHandler(HttpServletRequest req, Exception e) {
log.error("请求方法异常信息: {},请求接口: {}", e, req.getRequestURI());
return ReturnResult.error(
REQUEST_METHOD_ERROR.getCode(),
REQUEST_METHOD_ERROR.getMessage() + RIGHT_PARENTHESES + e.getMessage() + LEFT_PARENTHESES);
}
@ExceptionHandler(value = MyBatisSystemException.class)
@ResponseBody
public ReturnResult sqlSyntaxErrorExceptionHandler(HttpServletRequest req, Exception e) {
log.error("MyBatis系统异常信息: {},请求接口: {}", e, req.getRequestURI());
return ReturnResult.error(
INNER_FRAME_EXCEPTION.getCode(),
INNER_FRAME_EXCEPTION.getMessage() + RIGHT_PARENTHESES + e.getMessage() + LEFT_PARENTHESES);
}
@ExceptionHandler(value = AuthenticationException.class)
public ReturnResult incorrectCredentialsException(
HttpServletRequest request, AuthenticationException e) {
log.error("用户名或密码不正确: {}, 请求接口: {}", e, request.getRequestURI());
return ReturnResult.error(USER_CREDENTIALS_ERROR);
}
@ExceptionHandler(value = UserException.class)
public ReturnResult incorrectUserException(HttpServletRequest request, UserException e) {
log.error("用户信息异常: {}, 请求接口: {}", e, request.getRequestURI());
return ReturnResult.error(e.getCode(), e.getMessage());
}
@ExceptionHandler(value = Exception.class)
@ResponseBody
public ReturnResult exceptionHandler(HttpServletRequest req, Exception e) {
e.printStackTrace();
log.error("未知异常: {}, 请求接口: {}", e, req.getRequestURI());
return ReturnResult.error(
INTERNAL_SERVER_ERROR.getCode(),
INTERNAL_SERVER_ERROR.getMessage() + RIGHT_PARENTHESES + e.getMessage() + LEFT_PARENTHESES);
}
}
2.2 自定义业务异常类
import com.sugon.cloud.lowcode.result.BaseResultInterface;
import com.sugon.cloud.lowcode.result.CodeMessageEnum;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
@ApiModel(description= "业务异常数据")
public class BizException extends RuntimeException implements BaseResultInterface {
private static final long serialVersionUID = 1L;
@ApiModelProperty(value = "错误码")
private String code;
@ApiModelProperty(value = "错误信息")
private String message;
public BizException() {
super();
}
public BizException(CodeMessageEnum codeMessageEnum) {
super(codeMessageEnum.getCode());
this.code = codeMessageEnum.getCode();
this.message = codeMessageEnum.getMessage();
}
public BizException(CodeMessageEnum codeMessageEnum, Throwable cause) {
super(codeMessageEnum.getCode(), cause);
this.code = codeMessageEnum.getCode();
this.message = codeMessageEnum.getMessage();
}
public BizException(CodeMessageEnum codeMessageEnum, String message, Throwable cause) {
super(codeMessageEnum.getCode(), cause);
this.code = codeMessageEnum.getCode();
this.message = message;
}
public BizException(String message) {
super(message);
this.message = message;
}
public BizException(String code, String message) {
super(code);
this.code = code;
this.message = message;
}
public BizException(String code, String message, Throwable cause) {
super(code, cause);
this.code = code;
this.message = message;
}
@Override
public Throwable fillInStackTrace() {
return this;
}
@Override
public String getCode() {
return this.code;
}
@Override
public String getMessage() {
return this.message;
}
}
3. 统一返回格式
在上述代码中,所有的异常处理方法返回的是ReturnResult
对象,它封装了返回给前端的数据。ReturnResult
类的设计使得前端可以统一解析和展示错误信息。
3.1 返回结果类
import com.alibaba.fastjson.JSONObject;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import static com.sugon.cloud.lowcode.result.CodeMessageEnum.*;
@Setter
@Getter
@ApiModel(description= "返回响应数据")
public class ReturnResult<T> {
@ApiModelProperty(value = "状态码")
private String code;
@ApiModelProperty(value = "响应信息")
private String message;
@ApiModelProperty(value = "响应对象")
private T result;
@ApiModelProperty(value = "是否成功")
private boolean success = true;
public ReturnResult() {}
public ReturnResult(CodeMessageEnum codeMessageEnum) {
this.code = codeMessageEnum.getCode();
this.message = codeMessageEnum.getMessage();
}
public static ReturnResult success() {
return success(null);
}
public static <T> ReturnResult<T> success(T data) {
return success(SUCCESS, data);
}
public static <T> ReturnResult<T> loginSuccess(T data) {
return success(SUCCESS_LOGIN, data);
}
public static ReturnResult loginOutSuccess() {
return success(SUCCESS_LOGOUT, null);
}
private static <T> ReturnResult<T> success(CodeMessageEnum codeMessageEnum, T data) {
ReturnResult<T> result = new ReturnResult<>();
result.setCode(codeMessageEnum.getCode());
result.setMessage(codeMessageEnum.getMessage());
result.setResult(data);
return result;
}
public static ReturnResult error(CodeMessageEnum codeMessageEnum) {
return error(codeMessageEnum.getCode(), codeMessageEnum.getMessage());
}
public static ReturnResult error(CodeMessageEnum codeMessageEnum, String message) {
return error(codeMessageEnum.getCode(), message);
}
public static ReturnResult error(String code, String message) {
ReturnResult result = new ReturnResult();
result.setCode(code);
result.setMessage(message);
result.setSuccess(false);
return result;
}
@Override
public String toString() {
return JSONObject.toJSONString(this);
}
}
4. 总结
通过@RestControllerAdvice
和@ExceptionHandler
,我们可以在Spring Boot应用中实现全局异常处理,统一管理和处理所有异常。这样不仅可以
减少重复代码,还能使代码更加整洁,提高可维护性。同时,通过统一的返回格式,前端处理响应数据时也能更加方便。
希望这篇文章对您在Spring Boot中实现全局异常处理有所帮助。如有任何问题或建议,欢迎交流探讨。