java - 使用 jar 时抛出异常

Question

我在netbeans中创建了一个项目，使用SQLite作为数据库。当我在netbeans中运行它时，它运行得很好，当我使用“java -jar .jar”运行jar时，它会抛出此异常

H:>java -jar Remote_PC_Manger.jar Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at com.halorpm.main.LocalDB.checkAnonymous(LocalDB.java:74) at com.halorpm.main.MainForm.initComponents(MainForm.java:172) at com.halorpm.main.MainForm.(MainForm.java:137) at com.halorpm.main.Core.(Core.java:32) at com.halorpm.main.Core$3.run(Core.java:142) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$200(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Sour ce) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source)

MainForm.java


/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package com.halorpm.main;

import java.awt.SystemTray;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.sql.SQLException;

/**
 *
 * @author Abhijith S
 */
public class MainForm extends javax.swing.JFrame {

    public String fullname;
    public String key;
    public int status;

    public MainForm() {



        Thread getinfo = new Thread() {

          @Override
          public void run() {

                try {


        // Send the request
        URL url = new URL("http://demiracles.com/halo/cgi/getmisc.php?uname="+Login.username+"&key=name");
        URL url1 = new URL("http://demiracles.com/halo/cgi/getmisc.php?uname="+Login.username+"&key=skey");
        URLConnection conn = url.openConnection();
        URLConnection conn1 = url1.openConnection();

        conn.setDoOutput(true);
      //  OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());

        //write parameters
       // writer.write(data);
      //  writer.flush();

        // Get the response
        StringBuilder answer = new StringBuilder();
        StringBuilder answer1 = new StringBuilder();
        BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        BufferedReader reader1 = new BufferedReader(new InputStreamReader(conn1.getInputStream()));
        String line;
        while ((line = reader.readLine()) != null) {
            //System.out.println(line);
            answer.append(line);
        }
        while ((line = reader1.readLine()) != null) {
            //System.out.println(line);
            answer1.append(line);
        }

       // writer.close();
        reader.close();
        reader1.close();

        //Output the response
        //System.out.println(answer.toString());
        fullname = answer.toString();
        key = answer1.toString();

        regname.setText(fullname);
        lic.setText(key);
        expire.setText("2018-November-20");







    } catch (MalformedURLException ex) {
        ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

          }

        };
        getinfo.start();

        /* Thread mainer = new Thread(){


                 public void run(){

                    System.out.println("out");

               while(true){
                try{
                                    System.out.println("sasasa");
                    URL url = new URL("http://demiracles.com/halo/cgi/java_checker.php?uname="+Login.username+
                                            "&pwd="+Login.password);
                    URLConnection urlcon = url.openConnection();
                    BufferedReader bf = new BufferedReader(new InputStreamReader(urlcon.getInputStream()));
                    String xresponse = bf.readLine();
        System.out.println("In ThreadCheck"+xresponse);
        new Functions(xresponse);
        break;


           }catch(Exception x){     

               System.out.println(x);

           }
                    }   


               }




            };
            mainer.start();

        */




        initComponents();


    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        buttonGroup1 = new javax.swing.ButtonGroup();
        buttonGroup2 = new javax.swing.ButtonGroup();
        buttonGroup3 = new javax.swing.ButtonGroup();
        regname = new javax.swing.JLabel();
        jCheckBox1 = new javax.swing.JCheckBox();
        lic = new javax.swing.JLabel();
        expire = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        jLabel3 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        jLabel1 = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setMinimumSize(new java.awt.Dimension(640, 480));
        setResizable(false);
        getContentPane().setLayout(null);
        getContentPane().add(regname);
        regname.setBounds(400, 40, 210, 20);

        jCheckBox1.setText("Anonymous");
        LocalDB ob = new LocalDB();
        int res = ob.checkAnonymous();
        if(res==1) {

            jCheckBox1.setSelected(true);

        }
        jCheckBox1.addItemListener(new java.awt.event.ItemListener() {
            public void itemStateChanged(java.awt.event.ItemEvent evt) {
                jCheckBox1ItemStateChanged(evt);
            }
        });
        jCheckBox1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jCheckBox1ActionPerformed(evt);
            }
        });
        getContentPane().add(jCheckBox1);
        jCheckBox1.setBounds(40, 190, 81, 23);
        getContentPane().add(lic);
        lic.setBounds(400, 70, 210, 20);
        getContentPane().add(expire);
        expire.setBounds(400, 100, 210, 20);

        jLabel2.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N
        jLabel2.setText("Registered to : ");
        getContentPane().add(jLabel2);
        jLabel2.setBounds(310, 40, 90, 15);

        jLabel3.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N
        jLabel3.setText("License         : ");
        getContentPane().add(jLabel3);
        jLabel3.setBounds(310, 70, 90, 15);

        jLabel4.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N
        jLabel4.setText("Expire on      :");
        getContentPane().add(jLabel4);
        jLabel4.setBounds(310, 100, 90, 15);

        jLabel1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/com/halorpm/main/bg_main.png"))); // NOI18N
        getContentPane().add(jLabel1);
        jLabel1.setBounds(0, 0, 640, 480);

        pack();
    }// </editor-fold>

    private void jCheckBox1ActionPerformed(java.awt.event.ActionEvent evt) {                                           




    }                                          

    private void jCheckBox1ItemStateChanged(java.awt.event.ItemEvent evt) {                                            

  FileManager ob = new FileManager();
  LocalDB db = new LocalDB();

        if(jCheckBox1.isSelected()== true) {


           db.addUpdate(1);

           ob.createFile();
            this.setVisible(false);

            if(Core.appStatus==0) {

                Core.runTray();

            }




        }else {

            db.addUpdate(0);
            ob.deleteFile();

        }




    }                                           

    public  void viewDisplay() {

        setVisible(true);

    }

    /**
     * @param args the command line arguments
     */

    // Variables declaration - do not modify
    private javax.swing.ButtonGroup buttonGroup1;
    private javax.swing.ButtonGroup buttonGroup2;
    private javax.swing.ButtonGroup buttonGroup3;
    private javax.swing.JLabel expire;
    protected javax.swing.JCheckBox jCheckBox1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel lic;
    private javax.swing.JLabel regname;
    // End of variables declaration
}



enter code here
enter code here

LocalDB.java



/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package com.halorpm.main;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 *
 * @author Abhijith S
 */
public class LocalDB {

    private Connection con;
    protected Statement st;
  //  protected ResultSet res;
    int status;
    String uname;
    String pass;

    public LocalDB() {

            try {
         // sqlite driver
  Class.forName("org.sqlite.JDBC");
  // database path, if it's new database,
  // it will be created in the project folder
  con = DriverManager.getConnection("jdbc:sqlite:halodb.db");

  try{

        st = con.createStatement();
       // String qry3 = "UPDATE userlog SET anonymous=1";


      // 




        //System.out.println("done");


        }catch(SQLException e) {



        }

        }catch(ClassNotFoundException | SQLException e) {





        }


    }

    public int checkAnonymous(){


        try {

            String qry1 = "SELECT * FROM userlog";

      // st.executeUpdate(qry3);
      ResultSet  res = st.executeQuery(qry1);
         while(res.next()) {


         status = res.getInt("anonymous");

         System.out.println("Anonymous = "+status);



         }




    }catch(SQLException e){



    }

    return status;
    }
   public void addUpdate(int a) {

        try {
                // String table = "CREATE  TABLE userlog (uname VARCHAR, pass VARCHAR, anonymous INTEGER, normal INTEGER)";
                 //String qry = "INSERT INTO userlog values('abi','12345',0,1)";
                 String qry3 = "UPDATE userlog SET anonymous="+a;
                 st.executeUpdate(qry3);


             }catch(SQLException e) {

                 e.printStackTrace();

             }

   }

}

Answer 1

当您使用-jar命令行选项时，它会忽略CLASSPATH。我怀疑您的 Netbeans 项目具有所有依赖项，而当您进入命令行时，这些依赖项会丢失。尝试再次运行:

java -cp %CLASSPATH%;Remote_PC_Manger.jar <main-class>

在 CLASSPATH 中设置所有库依赖项(例如 SQLite)(或者也将它们直接添加到命令行)。

编辑:

仔细观察后，我认为您的异常(LocalDB 中的第 74 行)似乎是这一行:

ResultSet  res = st.executeQuery(qry1);

这意味着 st 为 null -- 这意味着 st = con.createStatement(); 进一步失败。您正在捕获这些异常，但不对它们执行任何操作(正如 Hovercraft 所指出的)。至少记录它们。我想您会发现您遇到的异常是由于之前的问题造成的。

我怀疑当您从 jar 运行时，Class.forName("org.sqlite.JDBC"); 行会抛出 ClassNotFoundException。