如何在SpringBoot中優(yōu)雅的處理異常
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SpringBoot 統(tǒng)一異常處理 像這種統(tǒng)一異常的文章博客有許多，但是每個(gè)人使用都有自己的心得，我來(lái)總結(jié)一下自己使用的心得統(tǒng)一異常，顧名思義，就是統(tǒng)一管理項(xiàng)目中會(huì)方法的異常，然后進(jìn)行一個(gè)處理，Spring發(fā)生錯(cuò)誤后，底層會(huì)去請(qǐng)求一個(gè)/error的地址，拋出對(duì)應(yīng)的異常到頁(yè)面上，對(duì)客戶或者開發(fā)來(lái)說(shuō)都不是特別的友好使用統(tǒng)一異常處理的話，可以返回自定義的異常數(shù)據(jù)，閱讀性提高，優(yōu)雅的處理異常
使用異常
使用異常的方式很簡(jiǎn)單，Spring提供了兩個(gè)注解：@ControllerAdvice和@ExceptionHandler
@ControllerAdvice 控制器增強(qiáng)，使@ExceptionHandler、@InitBinder、@ModelAttribute注解的方法應(yīng)用到所有的 @RequestMapping注解的方法 @ExceptionHandler 異常處理器，此注解的作用是當(dāng)出現(xiàn)其定義的異常時(shí)進(jìn)行處理的方法
創(chuàng)建統(tǒng)一異常類
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.TypeMismatchException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.web.AbstractErrorController;
import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Controller;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartException;
import org.springframework.web.servlet.NoHandlerFoundException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.SQLException;
import java.util.Map;
/**
* 全局異常處理
* 一般情況下，方法都有異常處理機(jī)制，但不能排除有個(gè)別異常沒(méi)有處理，導(dǎo)致返回到前臺(tái)，因此在這里做一個(gè)異常攔截，統(tǒng)一處理那些未被處理過(guò)的異常
*
* @author ${author} on ${date}
*/
@ControllerAdvice
@Controller
@RequestMapping
public class GlobalExceptionHandler extends AbstractErrorController {
private static final Logger LOGGER = LoggerFactory.getLogger(GlobalExceptionHandler.class);
public GlobalExceptionHandler(ErrorAttributes errorAttributes) {
super(errorAttributes);
}
@Value("${server.error.path:${error.path:/error}}")
private static String errorPath = "/error";
/**
* sql異常
*
* @param req
* @param rsp
* @param ex
* @return
* @throws Exception
*/
@ResponseBody
@ExceptionHandler(SQLException.class)
public Result<String> sqlException(HttpServletRequest req, HttpServletResponse rsp, Exception ex) {
LOGGER.error("!!! request uri:{} from {} server exception:{}", req.getRequestURI(), RequestUtil.getIpAddress(req), ex == null ? null : ex);
return ResponseMsgUtil.builderResponse(1002, ex == null ? null : ex.getMessage(), null);
}
/**
* 500錯(cuò)誤.
*
* @param req
* @param rsp
* @param ex
* @return
* @throws Exception
*/
@ResponseBody
@ResponseStatus(code = HttpStatus.INTERNAL_SERVER_ERROR)
@ExceptionHandler(Exception.class)
public Result<String> serverError(HttpServletRequest req, HttpServletResponse rsp, Exception ex) throws Exception {
LOGGER.error("!!! request uri:{} from {} server exception:{}", req.getRequestURI(), RequestUtil.getIpAddress(req), ex == null ? null : ex);
return ResponseMsgUtil.builderResponse(1002, ex == null ? null : ex.getMessage(), null);
}
/**
* 404的攔截.
*
* @param request
* @param response
* @param ex
* @return
* @throws Exception
*/
@ResponseBody
@ResponseStatus(code = HttpStatus.NOT_FOUND)
@ExceptionHandler(NoHandlerFoundException.class)
public Result<String> notFound(HttpServletRequest request, HttpServletResponse response, Exception ex) throws Exception {
LOGGER.error("!!! request uri:{} from {} not found exception:{}", request.getRequestURI(), RequestUtil.getIpAddress(request), ex);
return ResponseMsgUtil.builderResponse(404, ex == null ? null : ex.getMessage(), null);
}
@ExceptionHandler(MissingServletRequestParameterException.class)
@ResponseBody
public Result<String> paramException(MissingServletRequestParameterException ex) {
LOGGER.error("缺少請(qǐng)求參數(shù):{}", ex.getMessage());
return ResponseMsgUtil.builderResponse(99999, "缺少參數(shù):" + ex.getParameterName(), null);
}
//參數(shù)類型不匹配
//getPropertyName()獲取數(shù)據(jù)類型不匹配參數(shù)名稱
//getRequiredType()實(shí)際要求客戶端傳遞的數(shù)據(jù)類型
@ExceptionHandler(TypeMismatchException.class)
@ResponseBody
public Result<String> requestTypeMismatch(TypeMismatchException ex) {
LOGGER.error("參數(shù)類型有誤:{}", ex.getMessage());
return ResponseMsgUtil.builderResponse(99999, "參數(shù)類型不匹配,參數(shù)" + ex.getPropertyName() + "類型應(yīng)該為" + ex.getRequiredType(), null);
}
@ExceptionHandler(HttpRequestMethodNotSupportedException.class)
@ResponseBody
public Result<String> requestMethod(HttpRequestMethodNotSupportedException ex) {
LOGGER.error("請(qǐng)求方式有誤：{}", ex.getMethod());
return ResponseMsgUtil.builderResponse(99999, "請(qǐng)求方式有誤:" + ex.getMethod(), null);
}
@ExceptionHandler(MultipartException.class)
@ResponseBody
public Result<String> fileSizeLimit(MultipartException m) {
LOGGER.error("超過(guò)文件上傳大小限制");
return ResponseMsgUtil.builderResponse(99999, "超過(guò)文件大小限制,最大10MB", null);
}
/**
* 重寫/error請(qǐng)求, ${server.error.path:${error.path:/error}} IDEA報(bào)紅無(wú)需處理，作用是獲取spring底層錯(cuò)誤攔截
*
* @param request
* @param response
* @return
* @throws Exception
*/
@ResponseBody
@RequestMapping(value = "${server.error.path:${error.path:/error}}")
public Result<String> handleErrors(HttpServletRequest request, HttpServletResponse response) throws Exception {
HttpStatus status = getStatus(request);
if (status == HttpStatus.NOT_FOUND) {
throw new NoHandlerFoundException(request.getMethod(), request.getRequestURL().toString(), new HttpHeaders());
}
Map<String, Object> body = getErrorAttributes(request, true);
return ResponseMsgUtil.builderResponse(Integer.parseInt(body.get("status").toString()), body.get("message").toString(), null);
}
@Override
public String getErrorPath() {
return errorPath;
}
}
從上面可以看出來(lái)，我定義了sql異常，500異常，404異常該做的事情，通過(guò)@ExceptionHandler注解來(lái)攔截程序中的異常，比如執(zhí)行SQL時(shí)，拋出了異常，就會(huì)被統(tǒng)一異常給攔截，然后返回我們想要返回的數(shù)據(jù)
@ResponseStatus注解可加可不加，就是對(duì)響應(yīng)碼進(jìn)行攔截，如代碼上，對(duì)404響應(yīng)碼進(jìn)行了攔截
最下面的handleErrors方法，是對(duì)Spring底層訪問(wèn)/error的時(shí)候進(jìn)行了一次攔截，獲取當(dāng)前請(qǐng)求碼，如果是404.拋出404的異常
優(yōu)化處理異常怎么能沒(méi)有自定義返回?cái)?shù)據(jù)呢
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
/**
* 返回?cái)?shù)據(jù)結(jié)果集合
*/
public class Result<T> {
private Integer code;
private String resMsg;
private T data;
public Result() {
}
public Integer getCode() {
return this.code;
}
public void setCode(Integer resCode) {
this.code = resCode;
}
public String getResMsg() {
return this.resMsg;
}
public void setResMsg(String resMsg) {
this.resMsg = resMsg;
}
public T getData() {
return this.data;
}
public void setData(T data) {
this.data = data;
}
public String toJson() {
return this.data == null ? JSON.toJSONString(this) : this.toJson(SerializerFeature.WriteNullListAsEmpty, SerializerFeature.WriteNullStringAsEmpty, SerializerFeature.WriteMapNullValue);
}
public String toJson(SerializerFeature... features) {
return features == null ? this.toJson() : JSON.toJSONString(this, features);
}
public String toString() {
return "Result{code=" + this.code + ", resMsg='" + this.resMsg + '\'' + ", data=" + this.data + '}';
}
}
/**
* 返回?cái)?shù)據(jù)結(jié)果集合
* @author RuXuanWo on 2019/02/21
*/
public class ResponseMsgUtil {
public ResponseMsgUtil() {
}
public static <T> Result<T> builderResponse(int code, String msg, T data) {
Result<T> res = new Result();
res.setCode(code);
res.setResMsg(msg);
res.setData(data);
return res;
}
public static <T> Result<T> success(String msg) {
return builderResponse(0, msg, null);
}
public static <T> Result<T> success(String msg, T data) {
return builderResponse(0, msg, data);
}
public static <T> Result<T> success(T data) {
return builderResponse(0, "Success", data);
}
public static <T> Result<T> success() {
return builderResponse(0, "Success", null);
}
public static <T> Result<T> failure() {
return builderResponse(1, "Failure", null);
}
public static <T> Result<T> failure(String msg) {
return builderResponse(1, msg, null);
}
public static <T> Result<T> failure(T date) {
return builderResponse(-1, "Failure", date);
}
public static <T> Result<T> illegalRequest() {
return builderResponse(1008, "Illegal request", (T) null);
}
public static <T> Result<T> exception() {
return builderResponse(1002, "request exception", (T) null);
}
public static <T> Result<T> paramsEmpty() {
return builderResponse(1009, "the input parameter is null", (T) null);
}
}
測(cè)試
將這些準(zhǔn)備都做好以后，項(xiàng)目跑起來(lái)，訪問(wèn)一個(gè)接口，故意不傳某個(gè)必填項(xiàng)，就會(huì)被統(tǒng)一異常攔截，如下
{
code: 1002,
data: null,
msg: "Required String parameter 'id' is not present"
}
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