将 post 数据从一个 java servlet 写入另一个 java servlet

我正在尝试编写一个 servlet，它将通过 POST 发送 XML 文件（xml 格式的字符串）到另一个 servlet。 （非必要的 xml 生成代码替换为“Hello there”）

   StringBuilder sb=  new StringBuilder();
    sb.append("Hello there");

    URL url = new URL("theservlet's URL");
    HttpURLConnection connection = (HttpURLConnection)url.openConnection();                
    connection.setRequestMethod("POST");
    connection.setRequestProperty("Content-Length", "" + sb.length());

    OutputStreamWriter outputWriter = new OutputStreamWriter(connection.getOutputStream());
    outputWriter.write(sb.toString());
    outputWriter.flush();
    outputWriter.close();

这会导致服务器错误，并且永远不会调用第二个 servlet。

使用像这样的库，这种事情要容易得多Http客户端 http://hc.apache.org/httpclient-3.x/。甚至还有一个发布 XML 代码示例 http://svn.apache.org/viewvc/httpcomponents/oac.hc3x/trunk/src/examples/PostXML.java?view=markup:

PostMethod post = new PostMethod(url);
RequestEntity entity = new FileRequestEntity(inputFile, "text/xml; charset=ISO-8859-1");
post.setRequestEntity(entity);
HttpClient httpclient = new HttpClient();
int result = httpclient.executeMethod(post);