mysqlrs.java
- Java code
package anhua;import java.sql.*;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;public class mysqlrs { Connection con = null; Statement stat = null; PreparedStatement pstat = null; ResultSet rs = null; //无参数的构造函数 public mysqlrs(){} //取得数据库连接 public Connection getCon() { try{ Class.forName("com.mysql.jdbc.Driver").newInstance(); String url = "jdbc:mysql://localhost:3306/anhua?user=root&password=123456&useUnicode=true&characterEncoding=utf-8"; con = DriverManager.getConnection(url); } catch(Exception ex) { //ex.printStackTrace(); //System.err.print("Exception"); //out.print( "yes "); } return con; } //执行数据库查询并返回查询结果 public ResultSet query(String sql) { try{ con = getCon(); stat = con.createStatement(); rs = stat.executeQuery(sql); } catch(Exception ex) { //ex.printStackTrace(); System.err.print("SQLException"); } return rs; } //执行数据库更新 public void update(String sql) { try{ con = getCon(); stat = con.createStatement(); stat.executeUpdate(sql); } catch(Exception ex) { ex.printStackTrace(); } } //执行数据库更新 public void update(String sql,String[] args) { try{ con = getCon(); pstat = con.prepareStatement(sql); for (int i=0;i<args.length;i++) { pstat.setString(i+1,args[i]); } pstat.executeUpdate(); } catch(Exception ex) { ex.printStackTrace(); } } //关闭数据库连接 public void close() { try{ if (rs != null)rs.close(); if (stat != null)stat.close(); if (pstat != null)pstat.close(); if (con != null)con.close(); } catch(Exception ex) { ex.printStackTrace(); } } }index.jsp
- Java code
<%@ page contentType="text/html; charset=utf-8" language="java" import="java.sql.*" errorPage="" %><%@ page import="java.io.*" %><jsp:useBean id="myDBbean" class="anhua.mysqlrs"></jsp:useBean><%!private static int Num;public void japInit(){ Num=0; };%><!DOCTYPE HTML><html><head><meta charset="utf-8"><title>无标题文档</title></head><body><%="<br />欢迎<br />"%><% Num++; %><%="您是第"+Num+"个客人"%><Table border=2 bordercolor="#FFCCCC" align="center"><tr bgcolor=CCCCCC align=center> <td><b>书号</b></td> <td><b>书名</b></td> <td><b>作者</b></td> <td><b>出版社</b></td> <td><b>出版社</b></td> <td><b>出版社</b></td> </tr><%ResultSet rs = myDBbean.query("select * from users"); while(rs.next()){%> <tr align=center> <td><%=rs.getString("id")%></td> <td><%=rs.getString("uname")%></td> <td><%=rs.getString("upass")%></td> <td><%=rs.getString("phone")%></td> <td><%=rs.getString("intime")%></td> <td><%=rs.getString("ontime")%></td> </tr> <%}%> </Table></body></html>
现在总是出错.我分析错误感觉连接数据库都没过去.