使用已经完成的项目,希望它能够从单个.jar文件进行编译和运行,正如其他提到的那样,我应该使用Export - > Runnable Jar文件。
我选择我的主要Server类,同时选择“将所需的库打包到生成的JAR中”并按Finish。
现在我有了一个名为Server.jar
的文件尝试从控制台运行:java -jar Server.jar
并收到错误:
java.lang.NullPointerException
at server.Server.main(Server.java:34)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)
指的是:
Socket socket = serverSocket.accept();
MANIFEST.MF文件(自动创建):
Manifest-Version: 1.0
Rsrc-Class-Path: ./ json-simple.jar mysql-connector-java-5.1.42-bin.ja
r
Class-Path: .
Rsrc-Main-Class: server.Server
Main-Class: org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader
我厌倦了猜测问题,我是Java新手,首先进行编译。有什么帮助吗?
我的Server.java类:
package server;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import org.json.simple.parser.*;
public class Server {
public static void main(String args[]) throws ParseException{
ServerSocket serverSocket = null;
ArrayList<ClientComm> clients = new ArrayList<ClientComm>();
try{
new Config();
serverSocket = new ServerSocket(Config.getPort()); // can also use static final PORT_NUM , when defined
System.out.println("Server started");
System.out.println("test");
}
catch(IOException e){
e.printStackTrace();
System.out.println("Server error");
}
int clientID = 0;
while(true){
try{
System.out.println("Waiting for new connection");
Socket socket = serverSocket.accept();
clientID++;
System.out.println("New connection on socket: " + socket);
ClientComm clientComm = new ClientComm(socket, clientID);
clients.add(clientComm);
if(clientComm.checkAuth() == false) {
System.out.println("Client was dropped from connection because auth codes did not match");
socket.close();
}
else {
clientComm.start();
}
}
catch(Exception e){
e.printStackTrace();
System.out.println("Connection Error");
}
}
}
}
答案 0 :(得分:0)
问题早已解决。我个人不好,缺乏使用Java编程的经验。