通过JDBC连接数据库（二）

这次是建一个JDBCUtil类，代码如下：

package com.huawei;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * @author zhangzhao
 *
 * 2012-2-17下午08:53:27
 */
public final class JDBCUtil {
	private static	String url="jdbc:mysql://localhost:3306/jdbc";
	private static String user="root";
	private static String password="root";
	private JDBCUtil()
	{
		
	}
	static{
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public static Connection getConnection() throws SQLException{
		return DriverManager.getConnection(url, user, password);
	}
	public static void free(ResultSet rs,PreparedStatement pStatement,Connection conn){
		
		try {
			if(rs!=null){
				rs.close();
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally{
			try {
				if(pStatement!=null)
					pStatement.close();
			} catch (Exception e2) {
				// TODO: handle exception
			}
			finally{
				if(conn!=null)
					try {
						conn.close();
					} catch (SQLException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
			}
			
		}
		
	}


}

主函数如下：

package com.huawei;

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

/**
 * @author zhangzhao
 *
 * 2012-2-17下午08:39:25
 */
public class JDBCTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		template();
	}
	public static void template()
	{
		Connection conn=null;
		PreparedStatement pStatment=null;
		ResultSet rs=null;
		try {
			conn=JDBCUtil.getConnection();
			pStatment=conn.prepareStatement("select * from user");
			rs=pStatment.executeQuery();
			while(rs.next()){
				System.out.println(rs.getObject(1)+"\t"+rs.getObject(2)+"\t"+rs.getObject(3)+"\t"+rs.getObject(4));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		finally{
			//释放
			JDBCUtil.free(rs, pStatment, conn);
	}

}
}