java与mysql连接

package DBHelper;

import java.sql.*;

public class Demo {
public static void main(String[] args) {
String driver = "com.mysql.jdbc.Driver";
String dbName = "test";
String passwrod = "root";
String userName = "root";
String url = "jdbc:mysql://localhost:3306/" + dbName;
String sql = "select * from test";

try {
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, userName,
passwrod);
PreparedStatement ps = conn.prepareStatement(sql);
ResultSet rs = ps.executeQuery();
while (rs.next()) {
System.out.println("id : " + rs.getInt(1) + " name : "
+ rs.getString(2) );
}

// 关闭记录集
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

// 关闭声明
if (ps != null) {
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

// 关闭链接对象
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

} catch (Exception e) {
e.printStackTrace();
}
}

}