Ich habehat eine MySQL-Datenbank gehostet in einemWebserver. Ich habegewährt alle Privilegien und erlaubtmeine IP für die Verbindung zu dieser Datenbank aus der Ferne von meinem lokalen Computer. Es wird verbunden und ich kann Daten aus der Datenbank in meine Java Swing-Anwendung abrufen. Aber manchmalIch erhalte diese Fehlermeldung und meinVerbindung mit der gehosteten Datenbank schlägt fehl. Fehler wird unten angezeigt:

<code>Apr 7, 2012 12:49:20 AM scm.new_fas txtSearchKeyReleased
SEVERE: null
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 

** BEGIN NESTED EXCEPTION ** 

java.io.EOFException
MESSAGE: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.

STACKTRACE:

java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
    at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1997)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2411)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3250)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3179)
    at com.mysql.jdbc.Statement.executeQuery(Statement.java:1207)
    at scm.DBControl.getResult(DBControl.java:49)
    at scm.new_fas.txtSearchKeyReleased(new_fas.java:1686)
    at scm.new_fas.access$2300(new_fas.java:28)
    at scm.new_fas$23.keyReleased(new_fas.java:1136)
    at java.awt.Component.processKeyEvent(Component.java:5999)
    at javax.swing.JComponent.processKeyEvent(JComponent.java:2794)
    at java.awt.Component.processEvent(Component.java:5815)
    at java.awt.Container.processEvent(Container.java:2058)
    at java.awt.Component.dispatchEventImpl(Component.java:4410)
    at java.awt.Container.dispatchEventImpl(Container.java:2116)
    at java.awt.Component.dispatchEvent(Component.java:4240)
    at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
    at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:693)
    at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:958)
    at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:830)
    at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:657)
    at java.awt.Component.dispatchEventImpl(Component.java:4282)
    at java.awt.Container.dispatchEventImpl(Container.java:2116)
    at java.awt.Window.dispatchEventImpl(Window.java:2429)
    at java.awt.Component.dispatchEvent(Component.java:4240)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)


** END NESTED EXCEPTION **



Last packet sent to the server was 2 ms ago.
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2622)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3250)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3179)
    at com.mysql.jdbc.Statement.executeQuery(Statement.java:1207)
    at scm.DBControl.getResult(DBControl.java:49)
    at scm.new_fas.txtSearchKeyReleased(new_fas.java:1686)
    at scm.new_fas.access$2300(new_fas.java:28)
    at scm.new_fas$23.keyReleased(new_fas.java:1136)
    at java.awt.Component.processKeyEvent(Component.java:5999)
    at javax.swing.JComponent.processKeyEvent(JComponent.java:2794)
    at java.awt.Component.processEvent(Component.java:5815)
    at java.awt.Container.processEvent(Container.java:2058)
    at java.awt.Component.dispatchEventImpl(Component.java:4410)
    at java.awt.Container.dispatchEventImpl(Container.java:2116)
    at java.awt.Component.dispatchEvent(Component.java:4240)
    at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
    at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:693)
    at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:958)
    at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:830)
    at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:657)
    at java.awt.Component.dispatchEventImpl(Component.java:4282)
    at java.awt.Container.dispatchEventImpl(Container.java:2116)
    at java.awt.Window.dispatchEventImpl(Window.java:2429)
    at java.awt.Component.dispatchEvent(Component.java:4240)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)
</code>

Kann mir bitte jemand in dieser Situation helfen? Ich verstehe nicht, was falsch ist! Ist es der Server oder? Danke vielmals :)

Dies ist meine Klasse, um die DB zu verbinden:

<code>package scm;

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

public class DBControl {

    private static DBControl con;
    private static String severIp = null;
    private static String severPort = null;
    private static String userName = null;
    private static String password = null;
    private static ResultSet rs = null;
    private static Connection cc = null;

    public DBControl() {
    }

    public static synchronized DBControl getInstance() {
        if (con == null) {
            con = new DBControl();
        }
        return con;
    }

    public void setSeverIp(String Ip) {
        severIp = Ip;
    }

    public void setSeverPort(String Port) {
        severPort = Port;
    }

    public void SetUserName(String Name) {
        userName = Name;
    }

    public void setPassword(String passWord) {
        password = passWord;
    }

    public static ResultSet getResult(String url) throws Exception {
        Statement s = cc.createStatement();
        rs = s.executeQuery(url);
        return rs;
    }

    public static Connection getConnection() throws Exception {
//        try {
        Class.forName("com.mysql.jdbc.Driver");
        cc = (Connection) DriverManager.getConnection("jdbc:mysql://" + getSeverIp() + ":" + getSeverPort() + "/anuradha_rr", getUserName(), getPassword());
        return cc;
    }

    public void setResult(String url) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        cc = (Connection) DriverManager.getConnection("jdbc:mysql://" + getSeverIp() + ":" + getSeverPort() + "/anuradha_rr", getUserName(), getPassword());
        Statement s = (Statement) cc.createStatement();
        s.executeUpdate(url);
    }

    public static String getSeverIp() {
        return severIp;
    }

    public static String getSeverPort() {
        return severPort;
    }

    public static String getUserName() {
        return userName;
    }

    public static String getPassword() {
        return password;
    }
}
</code>