java(2014版)连接数据库的工具类

package util;



import java.io.IOException;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.Properties;



public class JdbcUtil {

	private static Connection conn;

	private static PreparedStatement pstmt;

	private static ResultSet rs;



	private JdbcUtil() {

		super();

		// TODO Auto-generated constructor stub

	}



	// 连接数据库的操作

	public static Connection getConn() {

		if (conn == null) {

			// 加载属性配置文件

			// 创建属性对象

			Properties prop = new Properties();

			try {

				// 加载指定名称的属性文件

				prop.load(JdbcUtil.class.getClassLoader().getResourceAsStream(

						"jdbc.properties"));

				try {

					// 根据文件的名称查找类文件

					Class.forName(prop.getProperty("driver"));



					// 创建连接对象

					try {

						conn = DriverManager.getConnection(

								prop.getProperty("url"),

								prop.getProperty("user"),

								prop.getProperty("pass"));

						System.out.println("连接数据库连接成功");



					} catch (SQLException e) {

						// TODO Auto-generated catch block

						System.out.println("连接数据库失败");

						e.printStackTrace();

					}

				} catch (ClassNotFoundException e) {

					// TODO Auto-generated catch block

					System.out

							.println("没有" + prop.getProperty("driver") + "文件");

					e.printStackTrace();

				}

			} catch (IOException e) {

				// TODO Auto-generated catch block

				System.out.println("属性文件加载出错");

				e.printStackTrace();

			}

		}

		return conn;

	}



	public static void release(ResultSet rs, PreparedStatement pstmt) {

		// 释放结果集

		if (rs != null) {

			try {

				rs.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		}

		// 释放准备语句

		if (pstmt != null) {

			try {

				pstmt.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		}

	}



	// 更新数据的操作增,删,改要用到的封装方法

	public static boolean upDate(String sql, Object[] obj) {

		boolean flag = false;



		try {

			// 准备语句的创建,带有sql命令的对象

			pstmt = getConn().prepareStatement(sql);



			for (int i = 1; i <= obj.length; i++) {

				pstmt.setObject(i, obj[i - 1]);

			}

			int i = pstmt.executeUpdate();

			if (i > 0) {

				flag = true;

			}



		} catch (SQLException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		} finally {

			release(rs, pstmt);

		}

		return flag;

	}



	// 进行批量删除处理

	public static boolean updateBatchDel(String sql, Object[] ids) {

		boolean flag = false;

		Connection conn = getConn();

		PreparedStatement pstmt = null;

		ResultSet rs = null;



		try {

			conn.setAutoCommit(false);

			pstmt = conn.prepareStatement(sql);

			for (int i = 0; i < ids.length; i++) {

				pstmt.setObject(1, ids[i]);

				System.out.println(sql + "---------------" + ids[i]);

				pstmt.addBatch();

			}

			int[] num = pstmt.executeBatch(); // 批量执行

			for (int i = 0; i < num.length; i++) {

				if (num[i] == 0) {

					try {

						conn.rollback(); // 进行事务回滚

						return flag;

					} catch (SQLException ex) {

						ex.printStackTrace();

					}

				}

			}

			conn.commit();// 提交事务

			flag = true;

		} catch (SQLException e) {



			e.printStackTrace();

		} finally {

			release(rs, pstmt);

		}

		return flag;

	}



	// 根据传入的表的名称,和每页数据得到传入表的所有的页数

		// tableName:::::操作的数据表名称

		// pagesize::::::每页显示的信息条数

	

		public static Integer getCountPage(String tableName, Integer pagesize) {

			Integer countPage = 0;

			String sql = "select count(*) as c from " + tableName;

			Connection conn = JdbcUtil.getConn();

			PreparedStatement pstmt = null;

			ResultSet rs = null;

			conn = JdbcUtil.getConn();

			try {

				pstmt = conn.prepareStatement(sql);

				rs = pstmt.executeQuery();

				if (rs.next()) {

					int countRecord = rs.getInt("c");

					countPage = countRecord % pagesize == 0 ? countRecord

							/ pagesize : countRecord / pagesize + 1;

				}

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			} finally {

				JdbcUtil.release(rs, pstmt);

			}

			return countPage;

		}

	

	

}