java实现的JDBCTemplate工具

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ResourceBundle;

/**
 * 数据库操作工具类
 * @author xrhou
 *
 */
public class DBUtils {
	
	//数据库连接地址
	public static String URL;
	//用户名
	public static String USERNAME;
	//密码
	public static String PASSWORD;
	//mysql的驱动类
	public static String DRIVER;
	
	private static ResourceBundle rb = ResourceBundle.getBundle("com.xrhou.util.db.db-config");
	
	private DBUtils(){}
	
	//使用静态块加载驱动程序
	static{
		URL = rb.getString("jdbc.url");
		USERNAME = rb.getString("jdbc.username");
		PASSWORD = rb.getString("jdbc.password");
		DRIVER = rb.getString("jdbc.driver");
		try {
			Class.forName(DRIVER);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}
	//定义一个获取数据库连接的方法
	public static Connection getConnection(){
		Connection conn = null;
		try {
			conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
		} catch (SQLException e) {
			e.printStackTrace();
			System.out.println("获取连接失败");
		}
		return conn;
	}
	
	/**
	 * 关闭数据库连接
	 * @param rs
	 * @param stat
	 * @param conn
	 */
	public static void close(ResultSet rs,Statement stat,Connection conn){
		try {
				if(rs!=null)rs.close();
				if(stat!=null)stat.close();
				if(conn!=null)conn.close();
		} catch (SQLException e) {
				e.printStackTrace();
		}
	}
	
}

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

public class JdbcTemplete {
	/**
	 * 实现增删改的抽象
	 * @param sql
	 * @param args
	 */
	public int update(String sql,Object... args){
		Connection conn = null;
		PreparedStatement ps = null;
		try{
			conn = DBUtils.getConnection();
			ps = conn.prepareStatement(sql);
			//设置占位符的参数
			if(args!=null){
				for (int i = 0; i < args.length; i++) {
					ps.setObject(i+1, args[i]);
				}
			}
			return ps.executeUpdate();
		}catch(SQLException e){
			e.printStackTrace();
			return -1;
		}finally{
			DBUtils.close(null, ps, conn);
		}
	}
	/**
	 * 查询方法的抽象
	 * @param sql
	 * @param handler
	 * @param args
	 * @return
	 */
	public Object query(String sql,ResultSetHandler handler,Object... args){
		Connection conn  = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = DBUtils.getConnection();
			ps = conn.prepareStatement(sql);
			if(args!=null){
				for (int i = 0; i < args.length; i++) {
					ps.setObject(i+1, args[i]);
				}
			}
			rs = ps.executeQuery();
			return handler.doHandler(rs);
		} catch (SQLException e) {
			e.printStackTrace();
			return null;
		}
		
	}
}

import java.sql.ResultSet;
import java.sql.SQLException;

public interface ResultSetHandler {

	public Object doHandler(ResultSet rs) throws SQLException;
}

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/friends
jdbc.username=root
jdbc.password=root