北大青鸟河北天泰JSP/Servlet第四章项目新闻发布系统-主题管理及首页新闻展示

package org.news.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import org.news.util.ConfigManager; /** * 数据库连接与关闭工具类。 * * @author 北大青鸟 */ public class BaseDao { private static String driver = ConfigManager.getProperty("driver");// 数据库驱动字符串 private static String url = ConfigManager.getProperty("url");// 连接URL字符串 private static String user = ConfigManager.getProperty("user"); // 数据库用户名 private static String password = ConfigManager.getProperty("password"); // 用户密码 protected Connection conn; static { try { Class.forName(driver); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /** * 获取数据库连接对象。 */ public Connection getConnection() { // 获取连接并捕获异常 try { if (conn == null || conn.isClosed()) conn = DriverManager.getConnection(url, user, password); } catch (SQLException e) { e.printStackTrace(); } return conn;// 返回连接对象 } /** * 关闭数据库连接。 * * @param conn * 数据库连接 * @param stmt * Statement对象 * @param rs * 结果集 */ public void closeAll(Connection conn, Statement stmt, ResultSet rs) { // 若结果集对象不为空，则关闭 try { if (rs != null && !rs.isClosed()) rs.close(); } catch (Exception e) { e.printStackTrace(); } // 若Statement对象不为空，则关闭 try { if (stmt != null && !stmt.isClosed()) stmt.close(); } catch (Exception e) { e.printStackTrace(); } // 若数据库连接对象不为空，则关闭 try { if (conn != null && !conn.isClosed()) conn.close(); } catch (Exception e) { e.printStackTrace(); } } /** * 增、删、改操作 * * @param sql * sql语句 * @param prams * 参数数组 * @return 执行结果 */ protected int executeUpdate(String sql, Object... params) { int result = 0; conn = this.getConnection(); PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); for (int i = 0; i < params.length; i++) { pstmt.setObject(i + 1, params[i]); } result = pstmt.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); } finally { closeAll(null, pstmt, null); } return result; } /** * 查询操作 * * @param sql * sql语句 * @param params * 参数数组 * @return 查询结果集 */ protected ResultSet executeQuery(String sql, Object... params) { conn = this.getConnection(); PreparedStatement pstmt = null; ResultSet rs = null; try { pstmt = conn.prepareStatement(sql); for (int i = 0; i < params.length; i++) { pstmt.setObject(i + 1, params[i]); } rs = pstmt.executeQuery(); } catch (SQLException e) { e.printStackTrace(); } return rs; } }