在 Servlet 中使用 JAR 文件不起作用？ [复制]

Question

我在 jsp/servlet 中创建了简单的 Web 应用程序。

登录后，想通过 TCP/IP 与远程服务器建立套接字通信 [IP 和端口可用]

我已经创建了进行套接字通信的类的 jar 文件。

当我在 servlet 中使用 jar 文件时，我得到以下异常

Feb 10, 2016 3:28:40 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [com.Temp.ServerServlet] in context with path [/Temp_Hosting] threw exception [Servlet execution threw an exception] with root cause
java.lang.NoClassDefFoundError: TCPClient/TCPClient
	at com.temp.ServerServlet.doPost(ServerServlet.java:51)
	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:169)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
	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$AbstractConnectionHandler.process(AbstractProtocol.java:625)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Unknown Source)

但是，当我使用构建 jar 的同一个类文件时，它工作得非常好。

所以在 servlet 中，调用下面进行套接字通信的类的方法可以正常工作。

下面是方法定义是类

 public String initializeServer(String _ipAddress, int portNo){
        String msg = "Failure";
        BufferedReader br = null;
        BufferedOutputStream bos = null;
        byte buffer[] = null;
        String send;
        try {
               Socket socket = new Socket(_ipAddress, portNo);
               br  = new BufferedReader(
                            new InputStreamReader(socket.getInputStream(), "UTF-8"));
               bos  = new BufferedOutputStream(socket.getOutputStream());
               send = "hi server\r\n";
               buffer = send.getBytes("UTF-8");
               bos.write(buffer,0,buffer.length);
               bos.flush();
               msg = br.readLine();
               System.out.println("Msg is :"+msg);
               bos.close();
               br.close();
               socket.close();
        } catch (UnknownHostException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
        } catch (IOException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
        }
        return msg;
        
 }

注意：

1. jar 文件被复制到 WEB-INF/class 文件夹，甚至添加到 类路径也是，但仍然没有结果。
2. 相同的 jar 文件在正常的 java 应用程序中正常工作。

提前感谢您的帮助..!!

Answer 1

通过 Oracle 将 jar 放入 WEB-INF/lib 为 instructed。