jsp連結sqlserver2008資料庫
阿新 • • 發佈：2019-01-26
最近在學習java，連資料庫的時候很鬱悶，main方法連結正確，jsp一呼叫就錯誤，後臺發現sqljdbc4.jar這個jar 在main中和在jsp中 是不一樣的。
3：直接測試看結果，在mian函式中
在main中只需右鍵專案build path 新增進sqljdbc4.jar 就好了，而在jsp中 你需要把sqljdbc4.jar copy到WebRoot/Web-inf/lib中
新增完以後，系統會自動幫你處理，2邊都可以使用。
1：DBHelper類：
package news2; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class dbHelper { private static final String DRIVER_CLASS ="com.microsoft.sqlserver.jdbc.SQLServerDriver"; private static final String DATABASE_URL = "jdbc:sqlserver://localhost:1433;databasename=news"; private static final String DATABASE_USER ="sa"; private static final String DATABASE_PASSWORD = "123456"; public static Connection getConnection(){ Connection dbConnection = null; try{ Class.forName(DRIVER_CLASS); dbConnection = DriverManager.getConnection(DATABASE_URL,DATABASE_USER,DATABASE_PASSWORD); } catch(Exception e){ e.printStackTrace(); } return dbConnection; } public static void closeConnection(Connection dbConnection){ try{ if(dbConnection != null && (!dbConnection.isClosed())){ dbConnection.close(); } } catch(SQLException sqlE){ sqlE.printStackTrace(); } } public static void closeResultSet(ResultSet res){ try{ if(res != null){ res.close(); res = null; } } catch(SQLException e){ e.printStackTrace(); } } public static void closeStatement(Statement stat){ try{ if(stat != null){ stat.close(); stat = null; } } catch(SQLException e){ e.printStackTrace(); } } }
2：呼叫DBHelper類
package news2; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.Date; import java.util.List; public class Control { public List<newsModel> getAllFirstLevelTitleList2(){ List<newsModel> list =new ArrayList<newsModel>(); Connection dbConnection = null; PreparedStatement pStatement = null; ResultSet res = null; try{ dbConnection = dbHelper.getConnection(); String sql = " select * from FirstLevelTitle order by Createtime desc "; pStatement = dbConnection.prepareStatement(sql); res = pStatement.executeQuery(); while(res.next()){ int id = res.getInt("id"); String Title = res.getString("TitleName"); String creator = res.getString("Creator"); Date time = res.getDate("CreateTime"); newsModel fTitle = new newsModel(id, Title, creator, time); list.add(fTitle); } }catch(SQLException sqlE){ sqlE.printStackTrace(); }finally{ dbHelper.closeResultSet(res); dbHelper.closeStatement(pStatement); dbHelper.closeConnection(dbConnection); } return list; } }
3：Model類
package news2; import java.util.Date; public class newsModel { private int id; private String titleName; private String creator; //建立者 private Date createTime; public newsModel(int id,String titleName,String creator,Date createTime) { this.id = id; this.titleName = titleName; this.creator = creator; this.createTime = createTime; } public int getId(){ return this.id; } public String getTitleName(){ return titleName; } public String getCreator(){ return creator; } public Date getCreateTime(){ return createTime; } public void setId(int par){ this.id = par; } public void setTitleName(String par){ this.titleName = par; } public void setCreator(String par){ this.creator = par; } public void setCreateTime(Date par){ this.createTime = par; } }
3：直接測試看結果，在mian函式中
package news2;
import java.util.*;
public class demo {
public static void main(String[] args){
Control c = new Control();
List<newsModel> list = c.getAllFirstLevelTitleList2();
System.out.println(list.size());
}
}
4：直接測試看結果，在 jsp頁面中
<%@page import="news2.newsModel"%>
<%@page import="news2.Control"%>
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
This is my JSP page. <br>
<% Control c = new Control();
List<newsModel> list = c.getAllFirstLevelTitleList2();
%>
<%=list.size() %>
</body>
</html>