我正在尝试使用 POST 方法在两个 servlet 之间进行通信。在本地，每件事都有效。但是，当我在真实服务器上部署我的 servlet 时，我遇到了一个异常。请问我该如何解决？
在我的第一个 servlet1 中，我有：
try {
gwtServlet = new URL("http://dbapp-test-env.elasticbeanstalk.com/Bdconnection");
HttpURLConnection servletConnection = (HttpURLConnection) gwtServlet.openConnection();
servletConnection.setRequestMethod("POST");
servletConnection.setDoOutput(true);
ObjectOutputStream objOut = new ObjectOutputStream(servletConnection.getOutputStream());
objOut.writeObject(obj);
objOut.flush();
objOut.close();
code = servletConnection.getResponseCode();
str = servletConnection.getErrorStream();
servletConnection.getInputStream();
} catch (Exception e) {
response.getWriter().println("Exception : "+getStackTrace(e));
response.getWriter().println("Error in catch of servlet 1: "+getStringFromInputStream(str));
e.printStackTrace();
}
如果你注意到了，我也会在catch.
我的第二个 servlet 位于http://dbapp-test-env.elasticbeanstalk.com/Bdconnection. 我在其中doPost：
try {
ObjectInputStream objIn = new ObjectInputStream(request.getInputStream());
SimObjectResult obj = (SimObjectResult) objIn.readObject();
} catch (Throwable e) {
printwriter.print(getStackTrace(e));
}
在执行期间，我在servelt 1中遇到了这个异常：
Exception : java.io.IOException: Server returned HTTP response code: 500 for URL: http://dbapp-test-env.elasticbeanstalk.com/Bdconnection
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1890)
at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1885)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:1884)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1457)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
at org.simulation.Simulation.doPost(Simulation.java:92)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:676)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Server returned HTTP response code: 500 for URL: http://dbapplicationcoapssample-test-env.elasticbeanstalk.com/Bdconnection
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1840)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
at org.simulation.Simulation.doPost(Simulation.java:90)
... 24 more
而内部服务器除外
Error in catch of servlet 1: java.lang.ClassNotFoundException: org.simulation.SimObjectResult at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:278)
at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:625)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1612)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1517)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1350)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
at org.stockage.Bdconnection.doPost(Bdconnection.java:78)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:683)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
在我的两个 servlet 的战争应用程序中，我有SimObjectResult.class