有时候我们经常遇到逻辑正常执行时返回客户端指定格式的数据，比如json，但是遇NullPointerException空指针异常,NoSuchMethodException调用的方法不存在异常，返回给客户端的是服务端异常堆栈信息，导致客户端不能正常解析数据；这明显不是我们想要的;或者我们已经用@RestControllerAdvice+ @ExceptionHandler进行统一异常处理，但是每次返回的时候都要写上return new RestRest().success(data)这里需要用到ResponseBodyAdvice在返回客户端之前进行统一处理。
- 先记录一下统一异常处理:
- 统一异常处理类
@Slf4j
@RestControllerAdvice
@ResponseBody
public class GlobalExceptionHandler {
@ExceptionHandler(value = {ParameterException.class})
public ErrorInfo<Object> parameterHandler(HttpServletRequest request, Exception exception) {
log.info("参数检测异常");
ErrorInfo<Object> errorInfo = new ErrorInfo<>();
errorInfo.setCode(ErrorCodeInfoEnum.PARAM_ERROR.getCode());
errorInfo.setMsg(ErrorCodeInfoEnum.PARAM_ERROR.getMsg());
errorInfo.setUrl(request.getRequestURI());
errorInfo.setData(exception);
log.info("异常信息:{}", errorInfo.toString());
return errorInfo;
}
@ExceptionHandler(value = {Exception.class})
public ErrorInfo<Object> defaultExceptionHandler(HttpServletRequest request, Exception exception) {
log.info("默认异常处理");
ErrorInfo<Object> errorInfo = new ErrorInfo<>();
errorInfo.setMsg(exception.getMessage());
errorInfo.setUrl(request.getRequestURI());
errorInfo.setData(exception);
log.info("默认异常处理信息：{}", errorInfo.toString());
return errorInfo;
}
@ExceptionHandler(value = NullPointerException.class)
private ErrorInfo<Object> nullPointerExceptionHandler(HttpServletRequest request, Exception exception) {
log.info("null异常处理");
ErrorInfo<Object> errorInfo = new ErrorInfo<>();
errorInfo.setMessage("空指针异常");
errorInfo.setStatus(2);
errorInfo.setData(exception);
errorInfo.setUrl(request.getRequestURI());
log.info("空指针异常", exception);
return errorInfo;
}
@ExceptionHandler(value = NoPermissionException.class)
private ErrorInfo<Object> noPermissionExceptionHandler(HttpServletRequest request, NoPermissionException exception) {
ErrorInfo<Object> errorInfo = new ErrorInfo<>();
errorInfo.setCode(ErrorCodeInfoEnum.NO_PERMISSION.getCode());
errorInfo.setMsg(ErrorCodeInfoEnum.NO_PERMISSION.getMsg());
errorInfo.setUrl(request.getRequestURI());
errorInfo.setData(exception);
log.info("没有权限异常", exception);
return errorInfo;
}
}
- 自定义异常类
@Getter
public class NoPermissionException extends RuntimeException {
public NoPermissionException() {
}
public NoPermissionException(String message) {
super(message);
}
public NoPermissionException(String message, Throwable cause) {
super(message, cause);
}
public NoPermissionException(Throwable cause) {
super(cause);
}
public NoPermissionException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
super(message, cause, enableSuppression, writableStackTrace);
}
}
- 用于对返回结果进行统一封装
@Data
@NoArgsConstructor
public class RestResult {
/**
* 请求是否成功
*/
private boolean success;
/**
* 请求状态吗
*/
private Integer code;
/**
* 请求返回信息描述
*/
private String msg;
/**
* 响应数据
*/
private Object data;
public RestResult(boolean success, String msg, Object data) {
this.success = success;
this.msg = msg;
this.data = data;
}
}
- 错误信息枚举
@Getter
public enum ErrorCodeInfoEnum {
PARAM_ERROR(1, "参数不正确"),
NO_PERMISSION(0,"没有权限")
;
private Integer code;
private String msg;
ErrorCodeInfoEnum(Integer code, String msg) {
this.code = code;
this.msg = msg;
}
}
- 业务层具体使用时抛出异常，等待统一处理
@Override
public LostVo queryLostVo(String lostId) {
log.info("lostId:{}", lostId);
if (!StringUtils.isNotEmpty(lostId)) {
throw new ParameterException("请检查参数是否正确");
} else {
Lost lost = lostMapper.selectByPrimaryKey(lostId);
User user = userMapper.selectByOpenId(lost.getLostOpenid());
LostVo lostVo = new LostVo();
…………
}
//
::: warning ResponseBodyAdvice
下面记录一下对返回结果的统一处理
:::
<!--此可以对@ResponseBody的返回结果在输出到响应之前做处理-->
public interface ResponseBodyAdvice<T> {
boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType);
T beforeBodyWrite(T body, MethodParameter returnType, MediaType selectedContentType,
Class<? extends HttpMessageConverter<?>> selectedConverterType,
ServerHttpRequest request, ServerHttpResponse response);
}
@Slf4j
@RestControllerAdvice(basePackages = {"com.gyx.lostandfound.controller"})
public class MyResponseBodyAdvice implements ResponseBodyAdvice {
/**
* 判断支持的类型
* @param returnType
* @param converterType
* @return
*/
@Override
public boolean supports(MethodParameter returnType, Class converterType) {
return MappingJackson2HttpMessageConverter.class.isAssignableFrom(converterType);
}
/**
* 对结果进行封装，或者进行加密处理
* @param body
* @param returnType
* @param selectedContentType
* @param selectedConverterType
* @param request
* @param response
* @return
*/
@Override
public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
if (body == null) {
return body;
} else if (body instanceof ErrorInfo) {
RestResult restResult = new RestResult();
restResult.setSuccess(false);
restResult.setCode(-1);
restResult.setMsg("出现异常");
restResult.setData(body);
return body;
} else if(body instanceof String){
return body;
} else {
RestResult restResult = new RestResult();
restResult.setSuccess(true);
restResult.setCode(200);
restResult.setData(body);
body = restResult;
return body;
}
}
}
controller层代码：
@ApiOperation(value = "用于查询自己所发布的物品信息")
@GetMapping(value = "query")
public Page<Object> selectRelease(@ApiParam(value = "用户openId") @RequestParam String openId,
@ApiParam(value = "状态") @RequestParam Integer status,
@ApiParam(value = "第几页") @RequestParam int pageIndex,
@ApiParam(value = "每页有多少个") @RequestParam int pageSize){
return userService.selectRelease(openId,status,pageIndex,pageSize);
利用postman测试一下：
输入url：localhost:8988/user/query?openId=111&status=1&pageIndex=1&pageSize=5
返回结果:
{
"success": true,
"code": 200,
"msg": null,
"data": {
"pageNum": 1,
"pageSize": 5,
"total": 0,
"pages": 1,
"list": []
}
}
最后补充一下目录结构：
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