在项目中我们通常会有一个通用的数据返回格式来返回给前端
首先定义了一个通用返回格式
import lombok.Data;
import java.io.Serializable;
/**
* @Description: 通用返回类
*/
@Data
public class CommonResult implements Serializable {
/**
* 0000为返回正常， 其它code均为请求错误
*/
private String code;
/**
* 返回数据
*/
private Object data;
/**
* 错误信息
*/
private String message;
public CommonResult() {
this.code = "0000";
this.message = "";
}
public CommonResult(Object data) {
this();
this.data = data;
}
public CommonResult(String message) {
this.code = "9999";
this.message = message;
}
public CommonResult(String code, String message) {
this.code = code;
this.message = message;
}
public CommonResult(ErrorCode errorCode) {
this.code = errorCode.getCode();
this.message = errorCode.getMessage();
}
}
有些异常要特殊处理所以定义了一个ErrorCode枚举
import lombok.Getter;
/**
* @Description: 业务通用异常代码
*/
@Getter
public enum ErrorCode {
SUCCESS("0000", "success"),
SERVER_ERROR("9999", "system error"),
REQUEST_ERROR("400", "请求错误"),
UNAUTHORIZED("401", "未授权"),
NOT_ACCESSIBLE("403", "不可访问"),
METHOD_NOT_ALLOWED("405", "方法不被允许"),
UNSUPPORTED_MEDIA_TYPE("415", "不支持当前媒体类型"),
TOKEN_LOSE_EFFICACY("1001","您的登录令牌已失效，请重新登录"),
;
private String code;
private String message;
ErrorCode(String code, String message) {
this.code = code;
this.message = message;
}
public static ErrorCode getByCode(String code) {
for (ErrorCode errorCode : ErrorCode.values()) {
if (errorCode.getCode().equals(code)) {
return errorCode;
}
}
return null;
}
}
接下来对返回的格式做一层封装方便调用
/**
* @Description: 返回类封装
*/
public class CommonResultTemplate {
public static CommonResult execute(Callback callback) {
CommonResult result;
try {
result = new CommonResult();
result.setData(callback.execute());
} catch (CommonException e) {
LoggerFactory.getLogger(Thread.currentThread().getStackTrace()[3].getClassName()).debug("business " +
"error", e);
if (e.getErrorCode() != null) {
result = new CommonResult(e.getErrorCode());
} else {
result = new CommonResult(e.getMessage());
}
} catch (Exception e) {
LoggerFactory.getLogger(Thread.currentThread().getStackTrace()[3].getClassName()).debug("business " +
"error", e);
result = new CommonResult(ErrorCode.SERVER_ERROR);
}
return result;
}
public interface Callback {
Object execute();
}
}
通过以上封装就可以在controller层用一行代码调用
public CommonResult getUserInfo() {
return CommonResultTemplate.execute(()->userService.getCurrentUser());
}
但是当请求没有进入controller层，比如发生401，403等请求错误时就无法返回这个通过格式，这时候就得对全局异常进行处理
在springboot中用ErrorController接口就可以了
import com.alibaba.fastjson.JSON;
import io.jsonwebtoken.JwtException;
import org.springframework.boot.autoconfigure.web.ErrorController;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.WebAttributes;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.util.WebUtils;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/**
* 全局异常处理
*/
@Controller
public class GlobalErrorController implements ErrorController {
//url不能替换
@RequestMapping("/error")
@ResponseBody
public static void error(HttpServletRequest request, HttpServletResponse response) throws IOException {
response.setContentType("application/json");
response.setCharacterEncoding("UTF-8");
Throwable error = (Throwable) request.getAttribute(WebUtils.ERROR_EXCEPTION_ATTRIBUTE);
if (null == error) {
error = (Throwable) request.getAttribute(WebAttributes.AUTHENTICATION_EXCEPTION);
}
if (null == error) {
error = (Throwable) request.getAttribute(WebAttributes.ACCESS_DENIED_403);
}
CommonResult result;
if (error instanceof JwtException) {
result = new CommonResult(ErrorCode.UNAUTHORIZED);
} else if (error instanceof AuthenticationException || error instanceof AccessDeniedException) {
result = new CommonResult(ErrorCode.NOT_ACCESSIBLE);
} else if (error instanceof MethodArgumentNotValidException) {
result = new CommonResult(ErrorCode.REQUEST_ERROR);
} else if (error instanceof CommonException) {
result = new CommonResult(((CommonException) error).getErrorCode());
} else {
result = new CommonResult(ErrorCode.SERVER_ERROR);
}
PrintWriter out = response.getWriter();
out.print(JSON.toJSONString(result));
out.flush();
out.close();
}
@Override
public String getErrorPath() {
return "/error";
}
}
不过ErrorController不能设置返回的http状态码，如果要想设置状态码需要使用@ControllerAdvice来处理
import com.zero.common.base.result.CommonException;
import com.zero.common.base.result.CommonResult;
import com.zero.common.base.result.ErrorCode;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
/**
* @Description: 全局异常处理
*/
@ControllerAdvice
public class ExceptionTranslator {
@ResponseBody
@ExceptionHandler(MethodArgumentNotValidException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
public CommonResult processValidationError(MethodArgumentNotValidException e) {
return new CommonResult(ErrorCode.REQUEST_ERROR);
}
@ResponseBody
@ExceptionHandler(CommonException.class)
@ResponseStatus(HttpStatus.FORBIDDEN)
public CommonResult processInvalidTokenException(CommonException e) {
return new CommonResult(e.getErrorCode());
}
@ResponseBody
@ExceptionHandler(AccessDeniedException.class)
@ResponseStatus(HttpStatus.FORBIDDEN)
public CommonResult processAccessDeniedException(AccessDeniedException e) {
return new CommonResult(ErrorCode.NOT_ACCESSIBLE);
}
@ResponseBody
@ExceptionHandler(HttpRequestMethodNotSupportedException.class)
@ResponseStatus(HttpStatus.METHOD_NOT_ALLOWED)
public CommonResult processMethodNotSupportedException(HttpRequestMethodNotSupportedException exception) {
return new CommonResult(ErrorCode.METHOD_NOT_ALLOWED);
}
@ExceptionHandler(Exception.class)
public ResponseEntity<CommonResult> processRuntimeException(Exception e) {
ResponseEntity.BodyBuilder builder;
CommonResult commonResult;
ResponseStatus responseStatus = AnnotationUtils.findAnnotation(e.getClass(), ResponseStatus.class);
if (responseStatus != null) {
builder = ResponseEntity.status(responseStatus.value());
commonResult = new CommonResult(responseStatus.value().value() + "", responseStatus.reason());
} else {
builder = ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR);
commonResult = new CommonResult(ErrorCode.INTERNAL_SERVER_ERROR);
}
return builder.body(commonResult);
}
}
另外要注意的是使用了@ControllerAdvice注解之后ErrorController就会失效，@ControllerAdvice功能更全面一些，可以设置返回的http状态码，不过ErrorController中也可以用通用返回格式中的code字段来代替
