JDBC问题
我写了两个简单的类。如下：
//////////////////////////////////
package www.liwenjie.com;

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

public class DataBaseUser {

private Statement statement;

public DataBaseUser() throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
System.out.println("Driver loaded");

Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/zhouyan?user=root&password=root&useUnicode=true&characterEncoding=GB2312");
System.out.println("Database connected");

statement = connection.createStatement();
}
}

//////////////////////////////////////////////////////////
package www.liwenjie.com;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.SQLException;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Test extends JFrame {

/**
* Launch the application
* @param args
*/
DataBaseUser dbuser;

public static void main(String args[]) {
try {
Test frame = new Test();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}

/**
* Create the frame
*/
public Test() {
super();
setBounds(100, 100, 500, 375);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

final JButton button = new JButton();
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
try {
dbuser = new DataBaseUser();
} catch (ClassNotFoundException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
} catch (SQLException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
}
}
});
button.setText("New JButton");
getContentPane().add(button, BorderLayout.CENTER);
//
}

}


/////////////////////////////////点击确定按钮报如下错误
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at www.liwenjie.com.DataBaseUser.<init>(DataBaseUser.java:13) at www.liwenjie.com.Test$1.actionPerformed(Test.java:40) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)