JAVA数据库的相关操作
数据库的相关操作：如连接、查询、添加、删除、修改、分页显示package study.database;
/***
Title: JSP模式学习
*
Description: 数据库的相关操作：如连接、查询、添加、删除、修改
*
Copyright: Copyright (c) 2004
*
Company:
* @author
* @version 1.0*/import java.sql.*;import java.io.*;import java.util.*;
public class Operation {//数据库驱动程序private String strDriver = "";//数据库连接字符串private String strURL = "";//数据库用户名private String username = "";//数据库密码private String password = "";
private Connection conn = null;private Statement stmt = null;ResultSet rs = null;
/** 读到数据库配置信息*/private void loadProp(){InputStream is = getClass().getResourceAsStream("/setup.txt");Properties props = new Properties();
try{props.load(is);}catch(Exception e){System.err.println("不能读取配置文件. 请确保setup.txt在classes指定的路径中");}
Enumeration propNames = props.propertyNames();while (propNames.hasMoreElements()) {String name = (String) propNames.nextElement();if (name.endsWith(".driver")) {String poolName = name.substring(0, name.lastIndexOf("."));strDriver = props.getProperty(poolName + ".driver");strURL = props.getProperty(poolName + ".url");username = props.getProperty(poolName + ".user");password = props.getProperty(poolName + ".password");}}}
/** 在创建Operation对象时连接数据库*/public Operation() {//读到数据库配置信息loadProp();
try{Class.forName(strDriver);}catch(java.lang.ClassNotFoundException e) {System.err.println("数据库连接错误：" + e.getMessage());}
try{conn=DriverManager.getConnection(strURL,username,password);}catch(SQLException ex) {System.err.println("数据库连接错误：" + ex.getMessage());}}
/** 数据库查询* sql:SQL查询语句*/public ResultSet query(String sql) {try{stmt=conn.createStatement();rs=stmt.executeQuery(sql);}catch(SQLException ex) {System.err.println("数据库查询错误：" + ex.getMessage());}
return rs;}
/** 数据库添加、修改、删除* sql:SQL语句*/public void update(String sql) {try{stmt=conn.createStatement();stmt.executeUpdate(sql);}catch(SQLException ex) {System.err.println("数据库更新错误："+ex.getMessage());}}
/** 得到查询结果的总记录数* rs:查询结果集*/public int totalRecord(ResultSet rs) throws Exception{int total=0;//指针移到最后一条记录上rs.last();total = rs.getRow();rs.first();
return total;}
/** 分页显示* currPage: 当前页数* pageSize: 页大小* pageCount: 总页数* filename: 使用分页的文件名(文件名后面要加?,多个参数以&分开，有参数的最后以&结束)* http://www.knowsky.com/ 返回字符串：
*/public String showPages(int currPage, int pageSize, int pageCount, String filename){String addr;
addr = "";
return addr;}
/** 关闭数据集*/public void closestmt() {try{stmt.close();}catch(SQLException ex) {System.err.println("数据集关闭错误："+ex.getMessage());}}
/** 关闭数据库连接*/public void closeconn() {try{conn.close();}catch(SQLException ex) {System.err.println("数据库连接关闭错误："+ex.getMessage());}}}
