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最近开发中遇到了一个文件上传乱码问题，经过一顿百度谷歌以后，解决了问题以后，现在把这个问题的前世今生都记录下。
一、问题描述
从前端上传文件后，后端接受到文件，显示文件名
//此时name=????全是问号，还非乱码
String name = multipartFile.getOriginalFilename();
二、问题原因分析
为什么会出现乱码？因为请求时，网关会先对请求进行解码，以便它们可用Zuul过滤器的可能修改，然后在过滤器构建过程后重新对请求进行编码，重新编码的过程由于编码不一致导致乱码。  在ServletDetectionFilter过滤中 Spring Cloud Zuul现在对于上传文件有两种处理方式，一种是用spring mvc，另一种是zuulServlet。spring mvc对文件处理不是很好，会导致乱码问题，zuulServlet则不会。 在zuul的过滤器中，有一个pre的过滤器 ServletDetectionFilter，他的执行顺序是-3，也是最先执行的过滤器，在这个过滤器中，有这么一段代码：
/*
* Copyright 2013-2015 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.cloud.netflix.zuul.filters.pre;
import javax.servlet.http.HttpServletRequest;
import org.springframework.cloud.netflix.zuul.util.RequestUtils;
import org.springframework.web.servlet.DispatcherServlet;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.http.HttpServletRequestWrapper;
import com.netflix.zuul.http.ZuulServlet;
/**
* Detects whether a request is ran through the {@link DispatcherServlet} or {@link ZuulServlet}.
* The purpose was to detect this up-front at the very beginning of Zuul filter processing
* and rely on this information in all filters.
* RequestContext is used such that the information is accessible to classes
* which do not have a request reference.
* @author Adrian Ivan
*/
public class ServletDetectionFilter extends ZuulFilter {
public ServletDetectionFilter() {
}
@Override
public String filterType() {
return "pre";
}
/**
* Must run before other filters that rely on the difference between
* DispatcherServlet and ZuulServlet.
*/
@Override
public int filterOrder() {
return -3;
}
@Override
public boolean shouldFilter() {
return true;
}
@Override
public Object run() {
RequestContext ctx = RequestContext.getCurrentContext();
HttpServletRequest request = ctx.getRequest();
if (!(request instanceof HttpServletRequestWrapper)
&& isDispatcherServletRequest(request)) {
ctx.set(RequestUtils.IS_DISPATCHERSERVLETREQUEST, true);
} else {
ctx.set(RequestUtils.IS_DISPATCHERSERVLETREQUEST, false);
}
return null;
}
private boolean isDispatcherServletRequest(HttpServletRequest request) {
return request.getAttribute(DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE) != null;
}
}
以下是常量定义代码
public class RequestUtils {
public static final String IS_DISPATCHERSERVLETREQUEST = "isDispatcherServletRequest";
public static boolean isDispatcherServletRequest() {
return RequestContext.getCurrentContext().getBoolean(IS_DISPATCHERSERVLETREQUEST);
}
public static boolean isZuulServletRequest() {
//extra check for dispatcher since ZuulServlet can run from ZuulController
return !isDispatcherServletRequest() && RequestContext.getCurrentContext().getZuulEngineRan();
}
}
在这个方法中，IS_DISPATCHER_SERVLET_REQUEST_KEY为false就会用ZuulServlet处理。如果没加/zuul前缀，IS_DISPATCHER_SERVLET_REQUEST_KEY就会置为true，就会用spring mvc上传。
三、解决办法
第一种解决方案，api接口前面 /zuul： 在不修改zuul默认配置参数的情况下，在上传文件的请求路径之前添加字符串“zuul”声明此请求被ZuulServlet处理。 例如在当前代码下，请求路径是： localhost:8080/up/upload 那么采用方案一解决中文乱码的请求路径就是: localhost:8080/zuul/up/upload 经过测试，中文乱码问题成功解决。 如果第一种方式，显示404，尝试第二种解决方案，改zuul的配置文件： 在zuul的配置文件中添加一个如下的属性： zuul.servlet-path=/
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