Daniel Try using plain PostMethod instead of MultipartPostMethod, unless you are really sure you need ability to submit multiple entities at once Oleg
-----Original Message----- From: Daniel Walsh [mailto:[EMAIL PROTECTED]] Sent: Dienstag, 28. Januar 2003 07:38 To: [EMAIL PROTECTED] Subject: MultipartPostMethod - Passing Parameters In trying to get to know the HttpClient component a bit, I attempted to write a simple program using a Java Servlet and the HttpClient API - the end result being that the client make a post to the servlet and the servlet return a brief HTML response to the client. The next step would be to transfer a file between the two, however, I'm running into some trouble with this first step. The only real requirements I've placed on this step is to use a post method instead of a get (because future steps would not be able to use a get), and to pass a parameter in the request. The parameter is where my problems start. After checking for this parameter on the server side, I throw an exception if it is non-existent. This is as far as the program has been running for me. I'm using HTTP Client 2.0 Alpha 2, and Commons Logging 1.0.2. I've included a couple of example classes that represent the basics of my code, and the thrown exception, in case anyone might have an idea as to what I am doing wrong: _________________________________________________________________________________________________ CLIENT CLASS - import org.apache.commons.httpclient.*; import org.apache.commons.httpclient.methods.*; import java.io.*; import java.net.*; public class HttpClientExmpl { public HttpClientExmpl() { init(); } public void init() { MultipartPostMethod postMethod = new MultipartPostMethod(); postMethod.setPath("/servlet/HttpClientExmplServlet"); postMethod.addParameter("param-name", "param-value"); HttpClient client = new HttpClient(); HostConfiguration hostConfig = new HostConfiguration(); hostConfig.setHost("localhost", 8081, "http"); client.setConnectionTimeout(30000); client.setHostConfiguration(hostConfig); try { client.executeMethod(postMethod); } catch(HttpException httpEx) { httpEx.printStackTrace(); } catch(IOException ioEx) { ioEx.printStackTrace(); } String responseString = postMethod.getResponseBodyAsString(); postMethod.releaseConnection(); System.out.println(responseString); } public static void main(String args[]) { new HttpClientExmpl(); } } _________________________________________________________________________________________________ SERVLET CLASS - import javax.servlet.*; import javax.servlet.http.*; import java.io.*; public class HttpClientExmplServlet extends HttpServlet { public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String paramValue = request.getParameter("param-name"); if(paramValue == null) throw new ServletException(new NullPointerException("The getParameter call returned null.")); response.setContentType("text/html"); PrintWriter writer = response.getWriter(); StringBuffer buf = new StringBuffer(); buf.append("<HTML>\n"); buf.append("<HEAD>\n<TITLE>HTTP Client Example Application</TITLE>\n</HEAD>\n"); buf.append("<BODY>\n"); buf.append("The servlet received the parameter sent within the post method.\n"); buf.append("</BODY>\n"); buf.append("</HTML>"); writer.write(buf.toString()); writer.flush(); writer.close(); } } _________________________________________________________________________________________________ RESULTING EXCEPTION - 2003-01-27 21:08:27 StandardWrapperValve[HttpClientExmplServlet]: Servlet.service() for servlet HttpClientExmplServlet threw exception java.lang.NullPointerException: The getParameter call returned null. at HttpClientExmplServlet.doPost(HttpClientExmplServlet.java:14) at javax.servlet.http.HttpServlet.service(HttpServlet.java:760) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:223) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:190) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566) at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564) at org.netbeans.modules.web.monitor.catalina.MonitorValve.invoke(MonitorValve.java:142) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943) at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566) at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:468) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174) at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472) at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943) at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1027) at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1125) at java.lang.Thread.run(Thread.java:536) Any suggestions would be greatly appreciated. Thanks, Daniel p.s. I'm not even sure that MultipartPostMethod is the most suitable object for this. If not, I'd appreciate a point in the right direction. -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
