我正在开发第一个JSP应用程序。我在MS Access中有两个使用DSN与JSP连接的数据库表。我要做的很简单。我有一个输入文本框，其中包含＆＃34; ID＆＃34;作为输入和用于查看记录的按钮。在按钮单击时，将从具有与文本框中的输入相同的ID的记录的两个表中检索结果集。
On按钮单击，应动态创建一个表，显示在结果集中检索的值.OnClick调用Javascript方法ShowData并将结果集的值传递给动态表。
所以形成元素＆＃39;在onClick之后将处理值，并且我的结果集在onClick之前有记录，正如您在代码中看到的那样，因此，我无法显示正确的结果，因为text-input在查询中变为null并且实现了不准确的结果集。
请指导我如何正确发送文本输入值以便在ButtonClick事件上查询。
希望我很清楚。 <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<!DOCTYPE html>
<%@page import="java.sql.*"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
<script language="javascript">
// creating dynamic tables
function showData(std_id,std_name,std_prog,std_email,std_semester,std_course,std_status,std_title,std_score,std_credit_hour){
var width = 25;
var theader = "<table border='5' id='table1' width = ' "+ width +"% '>";
var tbody = "";
var t2header = "<table border='5' id='table2' width = ' "+ width +"% '>";
var t2body ="";
tbody += "<tr>";
tbody += "<td>";
tbody += "Student ID";
tbody += "</td>";
tbody += "<td>";
tbody += std_id;
tbody += "</tr>";
tbody += "<tr>";
tbody += "<td>";
tbody += "Student Name";
tbody += "</td>";
tbody += "<td>";
tbody += std_name;
tbody += "</tr>";
tbody += "<tr>";
tbody += "<td>";
tbody += "Study Program";
tbody += "</td>";
tbody += "<td>";
tbody += std_prog;
tbody += "</tr>";
tbody += "<tr>";
tbody += "<td>";
tbody += "Email";
tbody += "</td>";
tbody += "<td>";
tbody += std_email;
tbody += "</tr>";
t2body += "<tr>";
t2body += "<td>";
t2body += "Semester";
t2body += "</td>";
t2body += "<td>";
t2body += "Course";
t2body += "</td>";
t2body += "<td>";
t2body += "Title";
t2body += "</td>";
t2body += "<td>";
t2body += "Status";
t2body += "</td>";
t2body += "<td>";
t2body += "Score";
t2body += "</td>";
t2body += "<td>";
t2body += "Credit Hour";
t2body += "</td>";
t2body += "</tr>";
t2body += "<tr>";
t2body += "<td>";
t2body += std_semester;
t2body += "</td>";
t2body += "<td>";
t2body += std_course;
t2body += "</td>";
t2body += "<td>";
t2body += std_title;
t2body += "</td>";
t2body += "<td>";
t2body += std_status;
t2body += "</td>";
t2body += "<td>";
t2body += std_score;
t2body += "</td>";
t2body += "<td>";
t2body += std_credit_hour;
t2body += "</td>";
t2body += "</tr>";
var tfooter = "</table>";
document.getElementById('wrapper').innerHTML = theader + tbody + tfooter;
document.getElementById('new_wrapper').innerHTML = theader + t2body + tfooter;
}
</script>
</head>
<body>
<div id="container" style="height:600px;width:700px;border:#6666ff; border-style: solid;background-color: aliceblue" >
<div id='content' style='height:330px;width: 550px;text-align: left;background-color: #F3F3F3;float: left;border:#6666ff'>
<h3>Enter Student ID to View Grade Book Information</h3>
<form id="myform" action="viewGradeBook.jsp" method="POST" >
Enter Student ID <input type="text" name="View_Std_Id" value="" /> // it need to be sent to query
<br/>
<%
String id_input = request.getParameter("View_Std_Id");
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
String conUrl = "jdbc:odbc:GradeBookDSN";
Connection con = DriverManager.getConnection(conUrl);
String sql = " SELECT * FROM StudentProfile , GradeBook WHERE StudentProfile.StudentID AND GradeBook.StudentID = '"+id_input+"' ";
PreparedStatement pStmt = con.prepareStatement(sql);
ResultSet rs = pStmt.executeQuery();
String id= "";
String name="";
String prog="";
String email ="";
String semester = "";
String course = "";
String status = "";
String title = "";
String score = "";
String credit_hour = "";
while(rs.next()){
// The row name is ―name‖ in database ―PersonInfo,// hence specified in the getString() method.
id = rs.getString("StudentID");
name = rs.getString("StudentName");
prog = rs.getString("StudyProgram");
email = rs.getString("Email");
semester = rs.getString("Semester");
course = rs.getString("Course");
status = rs.getString("Status");
title = rs.getString("Title");
score = rs.getString("Score");
credit_hour = rs.getString("CreditHour");
}
%>
<input type="button" value="View Record" onclick="showData(.......)"/>
<div id="wrapper"></div>
<br/>
<div id="new_wrapper"></div>
</form>
</div>
<div id='footer' style="background-color: #C2D5FC;clear: both;text-align: center;border:#6666ff">Copyrights@vu2014</div>
</div>
</body>
</html>
答案 0 :(得分：0)
您无法在单个JSP加载中实现此目的。
JSP是一个在单个Web请求上评估和呈现的视图（一个请求对应于您的网页加载）
如果您点击一个按钮，那么您已经在客户端，并且您无法访问服务器端的数据库。
您必须生成第二个请求（例如，而不是您放置提交的按钮，并将其放在表单中）并将参数传递给此请求以允许服务器执行SQL查询。
使用这种方法，你不需要在javascript中注入一些html。
您应该阅读有关N层架构，servlet和MVC模型的更多信息。
好的做法是：
此结构将帮助您
您可以尝试此链接作为开始 http://rathinasaba.wordpress.com/2011/10/13/simple-webapplication-using-servlet-and-jsp/