如何在尝试连接到Web服务时修复此错误500？

Question

我想连接到使用Visual Studio 2010 .NET 4的cXML Web服务，并且当我尝试使用URL向项目添加服务引用时出现以下错误（我隐藏了隐私网址）为什么我得到这个错误，我怎么才能连接到网络服务？...

There was an error downloading 'http://00.00.00.00:8080/xml/servlet/twaaserver?svcname=x10h015' 
The request failed with the error message: 
-- 
<h1>Error: 500</h1> 
<h2>Location: /xml/servlet/twaaserver</h2><b>Internal Servlet Error:</b><br> <pre>javax.servlet.ServletException 
    at processService.doProcess(processService.java:447) 
    at processService.run(processService.java:585) 
    at twaaserver.doGet(twaaserver.java:429) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:740) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) 
    at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405) 
    at org.apache.tomcat.core.Handler.service(Handler.java:287) 
    at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) 
    at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812) 
    at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758) 
    at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213) 
    at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416) 
    at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501) 
    at java.lang.Thread.run(Thread.java:534) 
</pre> 
<b>Root cause:</b> 
<pre>java.lang.NullPointerException 
    at eboservice.transformDataFeeds(eboservice.java:982) 
    at processService.doProcess(processService.java:279) 
    at processService.run(processService.java:585) 
    at twaaserver.doGet(twaaserver.java:429) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:740) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) 
    at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405) 
    at org.apache.tomcat.core.Handler.service(Handler.java:287) 
    at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) 
    at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812) 
    at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758) 
    at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213) 
    at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416) 
    at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501) 
    at java.lang.Thread.run(Thread.java:534) 
</pre> 


--. 
Metadata contains a reference that cannot be resolved: 'http://00.00.00.00:8080/xml/servlet/twaaserver?svcname=x10h015'. 
The content type text/html of the response message does not match the content type of the binding (application/soap+xml; charset=utf-8). If using a custom encoder, be sure that the IsContentTypeSupported method is implemented properly. The first 1024 bytes of the response were: '<h1>Error: 500</h1> 
<h2>Location: /xml/servlet/twaaserver</h2><b>Internal Servlet Error:</b><br><pre>javax.servlet.ServletException: Warning: can't output text before document element! Ignoring... 
    at processService.doProcess(processService.java:447) 
    at processService.run(processService.java:585) 
    at twaaserver.doGet(twaaserver.java:429) 
    at twaaserver.doPost(twaaserver.java:535) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:760) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) 
    at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405) 
    at org.apache.tomcat.core.Handler.service(Handler.java:287) 
    at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) 
    at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812) 
    at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758) 
    at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213) 
    at org.apache.tomcat.service.'. 
The remote server returned an error: (500) Internal Server Error. 
If the service is defined in the current solution, try building the solution and adding the service reference again. 

Answer 1

你说得对，我发现问题在于Web服务不是SOAP服务。这是一项REST服务。

问题是我试图通过Visual Studio工具添加服务引用。对于我所连接的这种服务，这是不可能的，因为它使用cXML并且是一个REST服务（它的工作原理非常不同）。

在我的解决方案中，我通过执行简单的POST和GET请求手动编写Web Service REST调用，并以字符串格式传递XML。

这个工作对我来说... 我用这个教程：https://developer.yahoo.com/dotnet/howto-rest_cs.html

Answer 2

似乎有什么问题，你的服务或如何调用它。

我通常做的第一件事是验证服务是否按预期工作。获取soapUI导入wsdl并执行一些示例调用。

如果您没有正确传递参数，有时服务会变得疯狂。如果它不与soapui一起工作，则说明服务供应商出了什么问题。