可以减少代码冗余
package cn.bdqn.Dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class BaseDao { private static String driver="com.mysql.jdbc.Driver"; private String url="jdbc:mysql://localhost:3306/newsmanagersystem"; private String user="root"; private String password="123456"; protected Connection conn; /** * 连接数据库 * @return */ public Connection getConnection(){ try { Class.forName(driver); conn=DriverManager.getConnection(url, user, password); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } /** * 关闭数据库 */ public void CloseAll(Connection conn,PreparedStatement pstmt,ResultSet rs){ if(rs!=null){ try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if(pstmt!=null){ try { pstmt.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if(conn!=null){ try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } /** * 查询操作 * @return */ public ResultSet executeQuery(String sql,Object...params){ PreparedStatement pstmt=null; ResultSet rs=null; try { pstmt=getConnection().prepareStatement(sql); if(params!=null){ for (int i = 0; i < params.length; i++) { pstmt.setObject(i+1, params[i]); } } rs=pstmt.executeQuery(); } catch (Exception e) { e.printStackTrace(); }finally{ CloseAll(null, null, null); } return rs; } /** * 删，改，插操作 * @param sql * @param params * @return */ public int executeUpdate(String sql,Object...params){ PreparedStatement pstmt=null; int result=0; try { pstmt=getConnection().prepareStatement(sql); if(params!=null){ for (int i = 0; i < params.length; i++) { pstmt.setObject(i+1, params[i]); } } result=pstmt.executeUpdate(); } catch (Exception e) { e.printStackTrace(); }finally{ CloseAll(conn, pstmt, null); } return result; } }