本文是在linux下用eclipse写的java程序，目的在于访问本地MySQL数据库，在java图形界面下用SQL命令访问数据库，并将结果以表格形式返回输出在界面上。
准备工作需要：
1.mysql数据库安装和基本命令，参考：点击打开链接http://blog.csdn.net/fykhlp/article/details/5949326
2.eclipse下jdbc驱动程序加载，驱动程序下载：点击打开链接http://download.csdn.net/detail/u010297828/8704503
jdbc链接数据库方法参考：点击打开链接http://www.2cto.com/os/201404/292825.html
注意，每新建一个java数据库工程都要在eclipse里导入jar包驱动，我的mysql版本是5.5的，JDBC驱动程序5.1.28完全适合mysql5.5,jdbc驱动可以到mysql官网下载，jdbc/connector/j，需要mysql账户（如果没有就注册），也可以下载我使用的版本，下载后解压 tarzxvf 下载的包，解要后的文件夹中有mysql-connector-java-[version]-bin.jar包
驱动程序测试成功能够正常访问mysql后，下面是本人关于在计算机屏幕上显示数据库表中数据的代码，其中"查询“窗口输入的SQL命令只能是要显示表格的命令，比如show，select ×from table等，对数据库的操作指令在”执行“窗口输入，点击执行或者查询按钮即可得到结果;
下面是界面截图：
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Font;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Vector;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import com.mysql.jdbc.ResultSetMetaData;
import com.mysql.jdbc.Statement;
public class DisplayQueryResults extends JFrame {
private String driverName = "com.mysql.jdbc.Driver";
private String databaseName = "jdbc:mysql://localhost/test";
private String user = "root";
private String password = "××mysql";
private JTextField inputQuery;
private JTextArea inputCommand;
private JButton queryButton,executeButton;
private JTable table;
private ResultSet resultSet;
private String queryStr = "show databases";
private String commandStr = " ";
private Connection conn;
public DisplayQueryResults() {
super("输入SQL语句，按查询显示查看结果！");
try {
Class.forName(driverName);
System.out.println("加载JDBC驱动程序成功");
conn = DriverManager.getConnection(databaseName, user, password);
} catch (ClassNotFoundException cne) {
// TODO Auto-generated catch block
System.err.println("加载JDBC驱动程序失败！");
cne.printStackTrace();
System.exit(1);
} catch (SQLException sqle) {
System.err.println("链接数据库失败");
sqle.printStackTrace();
System.exit(1);
}
Font font = new Font("宋体",Font.PLAIN,16);
inputQuery = new JTextField(queryStr);
inputCommand = new JTextArea(commandStr, 4, 30);
inputQuery.setFont(font);
inputCommand.setFont(font);
executeButton = new JButton("执行");
queryButton = new JButton("查询");
queryButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
getTable();// 执行sql语句并显示数据表
}
});
executeButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
executeSqlCommand();// 执行sql语句
}
});
JPanel executePanel = new JPanel();
executePanel.setLayout(new BorderLayout(5,5));
executePanel.add(new JScrollPane(inputCommand), BorderLayout.CENTER);
executePanel.add(executeButton,BorderLayout.EAST);
JPanel queryPanel = new JPanel();
queryPanel.setLayout(new BorderLayout(5,5));
queryPanel.add(inputQuery,BorderLayout.CENTER);
queryPanel.add(queryButton, BorderLayout.EAST);
JPanel topPanel = new JPanel();
topPanel.setLayout(new BorderLayout(5,5));
topPanel.add(executePanel, BorderLayout.NORTH);
topPanel.add(queryPanel, BorderLayout.SOUTH);
table = new JTable();
getContentPane().setLayout(new BorderLayout(5,5));
//getContentPane().add(executePanel, BorderLayout.NORTH);
getContentPane().add(topPanel, BorderLayout.NORTH);
getContentPane().add(table, BorderLayout.SOUTH);
getTable();
setSize(500, 300);
setVisible(true);
}
private void executeSqlCommand() {
// TODO Auto-generated method stub
String command = inputCommand.getText();
try {
Statement statement = (Statement) conn.createStatement();
statement.executeUpdate(command);
statement.close();
System.out.println("执行SQL命令成功！");
} catch (SQLException e) {
// TODO Auto-generated catch block
System.err.append("执行SQL命令失败，请检查语法");
e.printStackTrace();
}
}
private void getTable() {
// TODO Auto-generated method stub
try {
String query = inputQuery.getText();
Statement statement = (Statement) conn.createStatement();
resultSet = statement.executeQuery(query);
displayResultSet(resultSet);
statement.close();
System.out.println("执行SQL查询命令成功,Query OK");
} catch (SQLException sqle) {
System.out.println("执行sql语句失败！");
}
}
private void displayResultSet(ResultSet rs) {
// TODO Auto-generated method stub
boolean moreRecords;
try {
moreRecords = rs.next();
if (!moreRecords) {
JOptionPane.showMessageDialog(this, "结果中无记录");
setTitle("无显示");
return;
}
Vector columHeads = new Vector();
Vector rows = new Vector();
ResultSetMetaData rsmd = (ResultSetMetaData) rs.getMetaData();// 获取字段的名称
//获取字段名称组成的向量
for (int i = 1; i <= rsmd.getColumnCount(); i++) { //注意索引值从1开始
columHeads.addElement(rsmd.getColumnName(i));
}
do {
rows.addElement(getTextRow(rs, rsmd));
} while (rs.next());
table = new JTable(rows, columHeads);
JScrollPane scroller = new JScrollPane(table);
getContentPane().remove(1);
getContentPane().add(scroller, BorderLayout.CENTER);
getContentPane().validate();
} catch (SQLException e) {
// TODO Auto-generated catch block
System.err.println("显示结果失败");
e.printStackTrace();
}
}
private Vector getTextRow(ResultSet rs, ResultSetMetaData rsmd)
throws SQLException {
// TODO Auto-generated method stub
Vector currentRow = new Vector();
for (int i = 1; i <= rsmd.getColumnCount(); i++) {
currentRow.addElement(rs.getString(i));
}
return currentRow;
}
public void shutDown() {
try {
conn.close();
} catch (SQLException sqlex) {
System.err.println("不能断开连接");
sqlex.printStackTrace();
}
}
public static void main(String args[]) {
final DisplayQueryResults app = new DisplayQueryResults();
app.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
app.shutDown();
System.exit(0);
}
});
}
}