Help: Connecting MySQL Database to JTable

[Bobby Johnson]

Hello everyone. I am trying to connect my MySQL database to a JTable in Eclipse. Here is a sample of the database code for the application:

  class QueryTableModel extends AbstractTableModel    
    {   
        Vector cache;   
        int ColCount;   
        String[] headers;   
        Connection db=null;   
        Statement statement;   
        String driverName="com.mysql.jdbc.Driver";   
        //String driverName="com.microsoft.sqlserver.jdbc.SQLServerDriver";   
        //String driverName = "com.jnetdirect.jsql.JSQLDriver";   
        //String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";   
        String SQLLoadDatabaseQuery = "SELECT * FROM HouseHoldApplianceDatabase";   
        String URL = "jdbc:mysql://localhost:3306/DatabaseName";   
       // String serverName = "127.0.0.1";   
       // String portNumber = "1433";          
        //String mydatabase = serverName + ":" + portNumber;   
        //String currentURL = "jdbc:JSQLConnect://" + mydatabase;   
        //String username = "username";   
       // String password = "password";   
  
        public QueryTableModel()   
        {   
            cache = new Vector();   
            closeDB();   
            initDB(URL);   
            loadDB();   
        }   
           
        public String getColumnName(int i)   
        {   
            return headers[i];   
        }   
           
        public int getColumnCount()   
        {   
            return ColCount;   
        }   
           
        public int getRowCount()   
        {   
            return cache.size();   
               
        }   
           
        public Object getValueAt(int row, int col)   
        {   
            return ((String[]) cache.elementAt(row))[col];   
        }   
               
         public void loadDB()   
        {   
            cache = new Vector();   
            try {   
                
                 
              ResultSet rs = statement.executeQuery(SQLLoadDatabaseQuery);   
              ResultSetMetaData meta = rs.getMetaData();   
              ColCount = meta.getColumnCount();   
              
              headers = new String[ColCount];   
              for (int h = 1; h <= ColCount; h++) {   
                headers[h - 1] = meta.getColumnName(h);   
              }   
  
              while (rs.next()) {   
                String[] record = new String[ColCount];   
                for (int i = 0; i < ColCount; i++) {   
                  record[i] = rs.getString(i + 1);   
                }   
                cache.addElement(record);   
              }   
              fireTableChanged(null);   
            } catch (Exception e) {   
              e.printStackTrace();   
              System.err.println("Database still can't be loaded");   
            }   
              
        }   
            
         public void closeDB() {   
            try {   
              if (statement != null) {   
                statement.close();   
              }   
              if (db != null) {   
                db.close();   
              }   
            } catch (Exception e) {   
              System.out.println("Could not close the current connection.");   
              e.printStackTrace();   
            }   
         }   
            
         public void initDB(String url) {   
                try {         
                  Class.forName(driverName).newInstance();   
              //  Connection con = DriverManager.getConnection(url);   
                  db = DriverManager.getConnection(url,"******","******");   
                  statement = db.createStatement();   
                 System.err.println("The database in initialized");   
                } catch (Exception e) {   
                    System.err.println("Unable to find and load driver");   
                    e.printStackTrace();  
                    System.exit(1);   
                  }   
                }   
        }    
   

Now, this program is for a desktop application, not a web application. I already added the classpath variable for the MySQL driver as follows:

1. Right click the name of the project folder.
2. Click on properties.
3. Click on Java Build Paths.
4. Click on JRE libraries tab.
5. Click the Add External JAR button
6. Browse and find the mysql-connector-java-5.1.7-bin .jar file
7. Click ok.

After I ran the program, I got this exception:

Unable to find and load driver
com.mysql.jdbc.CommunicationsException: Communications link failure

Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2120)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:723)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:298)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at DamagedGoods$QueryTableModel.initDB(DamagedGoods.java:2897)
at DamagedGoods$QueryTableModel.<init>(DamagedGoods.java:2824)
at DamagedGoods.<init>(DamagedGoods.java:398)
at DamagedGoods.main(DamagedGoods.java:402)
Caused by: com.mysql.jdbc.CommunicationsException: Communications link failure

Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:335)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2043)
... 9 more
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:284)
... 10 more

Now my question is how can I get rid of this exception from my desktop application. Also, what is the default classpath location for the MySQL .JAR files for desktop application.