Question

如何用Eclipse连接MySQL数据库

Answer 1

　　1）eclipse开发环境里没有集成mysql的驱动，需要从以下地址下载连接驱动程序mysql-connector-java-XX-XX-XX.zip：
　　http://dev.mysql.com/downloads/connector/j
　　2）解压，只取文件mysql-connector-java-XX.XX.XX-bin.jar，将其引用到你需要连接mysql数据库的工程里，如：我在eclipsel里建了一个测试数据库连接的工程ConMysql。具体操作如下：
　　在工程ConMysql上点击右键
　　properties->Java Build Path->Libraries
　　点击Add External JARS...
　　选取解压后的mysql-connector-java-XX.XX.XX-bin.jar
　　3.编写测试代码1
　　import java.sql.*;
public class MysqlJdbc {
public static void main(String args[]) {
try {
Class.forName("com.mysql.jdbc.Driver"); //加载MYSQL JDBC驱动程序
//Class.forName("org.gjt.mm.mysql.Driver");
System.out.println("Success loading Mysql Driver!");
}
catch (Exception e) {
System.out.print("Error loading Mysql Driver!");
e.printStackTrace();
}
try {
Connection connect = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/mysql","root","");
//连接URL为 jdbc:mysql//服务器地址/数据库名
//后面的2个参数分别是登陆用户名和密码
System.out.println("Success connect Mysql server!");
Statement stmt = connect.createStatement();
ResultSet rs = stmt.executeQuery("select * from help_topic");
while (rs.next()) {
System.out.println(rs.getString("name"));
}
}
catch (Exception e) {
System.out.print("get data error!");
e.printStackTrace();
}
}
}
　　4.编写测试代码2
　　import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
　　public class LoginFrame extends JFrame implements ActionListener{
JLabel label = new JLabel("请输入用户名和密码：");
JTextField tfName = new JTextField(""); //输入用户名的文本框
JPasswordField tfPassword = new JPasswordField(""); //输入密码的密码框
JButton button = new JButton("登录");
public LoginFrame()
{
this.setTitle("登录验证");
button.addActionListener(this);
this.getContentPane().setLayout(new GridLayout(4,1));
this.getContentPane().add(label);
this.getContentPane().add(tfName);
this.getContentPane().add(tfPassword);
this.getContentPane().add(button);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(300,200);
this.setLocation(200,300);
this.setVisible(true);
}

public void actionPerformed(ActionEvent e)
{
try{
/*
* 连接MySQL数据库
*/
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection("jdbc:mysql://localhost/mysql","root","");
Statement stmt=conn.createStatement();
String sql = "select * from account where username='" + tfName.getText() + "'";
sql += " and password='" + tfPassword + "'"; //准备查询语句
ResultSet rs=stmt.executeQuery( sql );
if( rs.next() )
label.setText("合法用户"); //身份验证通过???
else
label.setText("非法用户"); //身份验证没有通过?????
}catch(Exception ee){
ee.printStackTrace();
}
}
public static void main(String[] args) {
new LoginFrame();
}
}