反向代理背后的GWT问题 - 无论是nginx还是apache

Question

当它在反向代理后面时,我遇到了这个问题.后端应用程序部署在上下文中 - 让我们称之为/上下文.

当我直接点击它时,GWT应用程序正常工作:

HTTP://主机:8080 /上下文/

我可以在它前面配置一个反向代理.这是我的nginx示例:

upstream backend {
    server 127.0.0.1:8080;
}

...

location / {
   proxy_pass        http://backend/context/;
}

但是,当我通过反向代理时,GWT感到困惑,说:

2009-10-04 14:05:41.140:/:WARN:  Login: ERROR: The serialization policy file '/C7F5ECA5E3C10B453290DE47D3BE0F0E.gwt.rpc' was not found; did you forget to include it in this deployment?
2009-10-04 14:05:41.140:/:WARN:  Login: WARNING: Failed to get the SerializationPolicy 'C7F5ECA5E3C10B453290DE47D3BE0F0E' for module 'https://hostname:444/'; a legacy, 1.3.3 compatible, serialization policy will be used.  You may experience SerializationExceptions as a result.
2009-10-04 14:05:41.292:/:WARN:  StoryService: ERROR: The serialization policy file '/0445C2D48AEF2FB8CB70C4D4A7849D88.gwt.rpc' was not found; did you forget to include it in this deployment?
2009-10-04 14:05:41.292:/:WARN:  StoryService: WARNING: Failed to get the SerializationPolicy '0445C2D48AEF2FB8CB70C4D4A7849D88' for module 'https://hostname:444/'; a legacy, 1.3.3 compatible, serialization policy will be used.  You may experience SerializationExceptions as a result.

换句话说,GWT没有得到它需要前置/上下文/ hen寻找C7F5ECA5E3C10B453290DE47D3BE0F0E.gwt.rpc这个词,但只有当请求来自代理时.解决方法是将上下文添加到网站的URL:

location /context/ {
    proxy_pass        http://backend/context/;
}

但这意味着上下文现在是用户看到的网址的一部分,而且很难看.

有人知道如何让GWT在这种情况下开心吗？

软件版本:
GWT - 1.7.0(与1.7.1相同的问题)
Jetty - 6.1.21(但tomcat下存在同样的问题)
nginx - 0.7.62(apache 2.x下同样的问题)

我使用DonsProxy查看了代理和后端之间的流量,但没有什么值得注意的.

Answer 1

我有同样的问题,我打开了一个错误报告:

http://code.google.com/p/google-web-toolkit/issues/detail?id=4817

问题是它被标记为"As Design",所以我认为它不会被修复.

我找到了这个解决方案.我扩展了类RemoteServiceServlet,并强制GWT从ContextName而不是URL开始加载序列化策略文件.然后我扩展了我的服务我的类而不是RemoteServiceServlet类.通过这种方式,应用程序将从其将被调用的URL取消链接.

这里有我的自定义类:

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.text.ParseException;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;

import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.google.gwt.user.server.rpc.SerializationPolicy;
import com.google.gwt.user.server.rpc.SerializationPolicyLoader;

public class MyRemoteServiceServlet extends RemoteServiceServlet
{
    @Override
    protected SerializationPolicy doGetSerializationPolicy(HttpServletRequest request, String moduleBaseURL, String strongName)
    {
        return MyRemoteServiceServlet.loadSerializationPolicy(this, request, moduleBaseURL, strongName);
    }


    /**
      * Used by HybridServiceServlet.
      */
      static SerializationPolicy loadSerializationPolicy(HttpServlet servlet,
      HttpServletRequest request, String moduleBaseURL, String strongName) {
    // The serialization policy path depends only by contraxt path
    String contextPath = request.getContextPath();

    SerializationPolicy serializationPolicy = null;


    String contextRelativePath = contextPath + "/";



      String serializationPolicyFilePath = SerializationPolicyLoader.getSerializationPolicyFileName(contextRelativePath
          + strongName);

      // Open the RPC resource file and read its contents.
      InputStream is = servlet.getServletContext().getResourceAsStream(
          serializationPolicyFilePath);
      try {
        if (is != null) {
          try {
        serializationPolicy = SerializationPolicyLoader.loadFromStream(is,
            null);
          } catch (ParseException e) {
        servlet.log("ERROR: Failed to parse the policy file '"
            + serializationPolicyFilePath + "'", e);
          } catch (IOException e) {
        servlet.log("ERROR: Could not read the policy file '"
            + serializationPolicyFilePath + "'", e);
          }
        } else {
          String message = "ERROR: The serialization policy file '"
          + serializationPolicyFilePath
          + "' was not found; did you forget to include it in this deployment?";
          servlet.log(message);
        }
      } finally {
        if (is != null) {
          try {
        is.close();
          } catch (IOException e) {
        // Ignore this error
          }
        }
      }

    return serializationPolicy;
      }
}

Answer 2

米歇尔,

感谢您使用示例servlet来处理此问题.但是,当我尝试使用您的方法时,它在反向代理环境中工作,但不在我的开发模式eclipse环境中.

我采取了一种方法,可以让我在开发和生产环境之间无缝移动.

正如你所做的那样,我覆盖了RemoteServiceServlet,但我只更换了以下内容......

@Override
protected SerializationPolicy doGetSerializationPolicy(
        HttpServletRequest request, String moduleBaseURL, String strongName) {
    //get the base url from the header instead of the body this way 
    //apache reverse proxy with rewrite on the header can work
    String moduleBaseURLHdr = request.getHeader("X-GWT-Module-Base");

    if(moduleBaseURLHdr != null){
        moduleBaseURL = moduleBaseURLHdr;
    }

    return super.doGetSerializationPolicy(request, moduleBaseURL, strongName);
}

在我的apache配置中,我添加了...

ProxyPass /app/ ajp://localhost:8009/App-0.0.1-SNAPSHOT/

RequestHeader edit X-GWT-Module-Base ^(.*)/app/(.*)$ $1/App-0.0.1-SNAPSHOT/$2

这种方法适用于所有场景,并将url"mucking"委托给apache的代理设置,这是我一直采用的方法.

对此方法的评论表示赞赏

Answer 3

我相当确定这里的正确答案是修补源代码并提交错误报告。另一种选择是运行 GWT 应用程序/在后端运行 GWT 应用程序。

我更喜欢前者，但后者也应该有效。如果您确实需要将事物分离到多个上下文中，请使用不同的端口号？