如何将值从一个jsp传递到另一个jsp以更新数据库
我有LookupStudent.jsp根据某些条件搜索并列出学生 这个jsp有一个指向另一个jsp UpdateStudent.jsp的ref链接 我想如何将值从一个jsp传递到另一个jsp以更新数据库,jsp,servlets,jstl,Jsp,Servlets,Jstl,我有LookupStudent.jsp根据某些条件搜索并列出学生 这个jsp有一个指向另一个jsp UpdateStudent.jsp的ref链接 我想 根据LookupStudent.jsp中的学生id在UpdateStudent.jsp中显示学生 根据步骤1中所做的更改更新表 你能帮我怎么做吗 LookupStudent.jsp <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Lookup Students</title>
</head>
<body class="body">
<form method="get" action="LookupStudentServlet">
<table border="0">
<tr align="left" valign="top">
<td>Student Name:</td>
<td><select name="fnameOperator">
<option value="Eq">Equals</option>
<option value="Sw">Starts With</option>
<option value="Ew">Ends With</option>
<option value="Co">Contains</option>
</select></td>
<td><input type="text" name="fname" /></td>
</tr>
<tr align="left" valign="top">
<td></td>
<td><input type="submit" name="submit" value="submit" /></td>
</tr>
</table>
</form>
<!-- List results -->
<c:if test="${not empty studentList}">
<table border="1" cellspacing="0" cellpadding="0" :>
<tr>
<th>ID</th>
<th>Title</th>
<th>First Name</th>
<th>Last Name</th>
</tr>
<c:forEach var="students" items="${studentList}">
<tr>
<td>${students.studentID}</td>
<td>${students.title}</td>
<td>${students.firstName}</td>
<td>${students.lastName}</td>
<td><c:url value="UpdateStudent.jsp" var="url">
<c:param name="StudentID" value="${students.studentID}" />
</c:url> <a href="${url}">edit</a>
</tr>
</c:forEach>
</table>
</c:if>
<p>There are ${fn:length(studentList)} results.</p>
</body>
</html>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Lookup Students</title>
</head>
<link rel="stylesheet" href="css/style.css" type="text/css"></link>
<body class="body">
<form method="get" action="UpdateStudent" class="form">
<table border="0">
<tr align="left" valign="top">
<td>Student ID:</td>
<td><input type="text" name="StudentID" /></td>
</tr>
<tr align="left" valign="top">
<td>Title:</td>
<td><input type="text" name="Title" /></td>
</tr>
<tr align="left" valign="top">
<td>First Name:</td>
<td><input type="text" name="Fname" /></td>
</tr>
<tr align="left" valign="top">
<td>Last Name:</td>
<td><input type="text" name="Lname" /></td>
</tr>
<tr align="left" valign="top">
<td></td>
<td><input type="submit" name="submit" value="submit"
class="fb8" /></td>
</tr>
</table>
</form>
</body>
</html>
查找学生
学生姓名：
等于
开始于
以
包含
身份证件
标题
名字
姓
${students.studentID}
${students.title}
${students.firstName}
${students.lastName}
有${fn:length（studentList）}个结果
package org.cms.controller;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.cms.model.StudentDAO;
/**
* Servlet implementation class ListStudent
*/
@WebServlet("/LookupStudentServlet")
public class LookupStudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
String fnameOperator = request.getParameter("fnameOperator");
//System.out.println(fnameOperator);
String fname = request.getParameter("fname");
String condition = "where 1=1 ";
if (fname!=null||fname.length()>0) {
if (fnameOperator.equalsIgnoreCase("Eq")) {
condition =condition+ "and first_name = '"+fname+"'";
}
else if (fnameOperator.equalsIgnoreCase("Sw")) {
condition =condition+ "and first_name like '"+fname+"%'";
}
else if (fnameOperator.equalsIgnoreCase("Ew")) {
condition =condition+ "and first_name like '%"+fname+"'";
}
else if (fnameOperator.equalsIgnoreCase("Co")) {
condition =condition+ "and first_name like '%"+fname+"%'";
}
}
//System.out.println(condition);
StudentDAO student = new StudentDAO();
List<StudentDAO> students = student.lookupStudent(condition);
request.setAttribute("studentList", students);
} catch (SQLException sqle) {
request.setAttribute("error", "Retrieving Students failed.");
sqle.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
}
finally {}
request.getRequestDispatcher("LookupStudent.jsp").forward(request, response);
}
}
package org.cms.controller;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.cms.model.StudentDAO;
/**
* Servlet implementation class ListStudent
*/
@WebServlet("/UpdateStudentServlet")
public class UpdateStudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
int studentID;
studentID = Integer.parseInt(request.getParameter("StudentID"));
//System.out.println(fnameOperator);
String condition = "where 1=1";
condition = condition+"and student_id = "+studentID;
System.out.println(condition);
StudentDAO student = new StudentDAO();
List<StudentDAO> students = student.lookupStudent(condition);
request.setAttribute("studentList", students);
} catch (SQLException sqle) {
request.setAttribute("error", "Retrieving Students failed.");
sqle.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
}
finally {}
request.getRequestDispatcher("UpdateStudent.jsp").forward(request, response);
}
}
package org.cms.controller；
导入java.io.IOException；
导入java.sql.SQLException；
导入java.util.List；
导入javax.servlet.ServletException；
导入javax.servlet.annotation.WebServlet；
导入javax.servlet.http.HttpServlet；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpServletResponse；
导入org.cms.model.StudentDAO；
/**
*Servlet实现类ListStudent
*/
@WebServlet（“/LookupStudentServlet”）
公共类LookupStudentServlet扩展了HttpServlet{
私有静态最终长serialVersionUID=1L；
/**
*@请参阅HttpServlet#doPost（HttpServletRequest请求，HttpServletResponse响应）
*/
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
试一试{
字符串fnameOperator=request.getParameter（“fnameOperator”）；
//System.out.println（fnameOperator）；
字符串fname=request.getParameter（“fname”）；
字符串条件=“其中1=1”；
如果（fname！=null | | fname.length（）>0）{
if（fnameOperator.equalsIgnoreCase（“Eq”））{
条件=条件+”，名字=“+fname+”；
}
else if（fnameOperator.equalsIgnoreCase（“Sw”））{
条件=条件+”和第一个名称，如“+fname+”%”；
}
else if（fnameOperator.equalsIgnoreCase（“Ew”））{
条件=条件+”和第一个名称，如“%”“+fname+”；
}
else if（fnameOperator.equalsIgnoreCase（“Co”））{
条件=条件+”和第一个_名称，如“%”+fname+“%”；
}
}
//系统输出打印项次（条件）；
StudentDAO student=新StudentDAO（）；
List student=student.lookupStudent（条件）；
setAttribute（“学生列表”，学生）；
}捕获（SQLException sqle）{
setAttribute（“错误”，“检索学生失败”）；
printStackTrace（）；
}
捕获（例外e）{
e、 printStackTrace（）；
}
最后{}
getRequestDispatcher（“LookupStudent.jsp”）.forward（请求，响应）；
}
}
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Lookup Students</title>
</head>
<body class="body">
<form method="get" action="LookupStudentServlet">
<table border="0">
<tr align="left" valign="top">
<td>Student Name:</td>
<td><select name="fnameOperator">
<option value="Eq">Equals</option>
<option value="Sw">Starts With</option>
<option value="Ew">Ends With</option>
<option value="Co">Contains</option>
</select></td>
<td><input type="text" name="fname" /></td>
</tr>
<tr align="left" valign="top">
<td></td>
<td><input type="submit" name="submit" value="submit" /></td>
</tr>
</table>
</form>
<!-- List results -->
<c:if test="${not empty studentList}">
<table border="1" cellspacing="0" cellpadding="0" :>
<tr>
<th>ID</th>
<th>Title</th>
<th>First Name</th>
<th>Last Name</th>
</tr>
<c:forEach var="students" items="${studentList}">
<tr>
<td>${students.studentID}</td>
<td>${students.title}</td>
<td>${students.firstName}</td>
<td>${students.lastName}</td>
<td><c:url value="UpdateStudent.jsp" var="url">
<c:param name="StudentID" value="${students.studentID}" />
</c:url> <a href="${url}">edit</a>
</tr>
</c:forEach>
</table>
</c:if>
<p>There are ${fn:length(studentList)} results.</p>
</body>
</html>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Lookup Students</title>
</head>
<link rel="stylesheet" href="css/style.css" type="text/css"></link>
<body class="body">
<form method="get" action="UpdateStudent" class="form">
<table border="0">
<tr align="left" valign="top">
<td>Student ID:</td>
<td><input type="text" name="StudentID" /></td>
</tr>
<tr align="left" valign="top">
<td>Title:</td>
<td><input type="text" name="Title" /></td>
</tr>
<tr align="left" valign="top">
<td>First Name:</td>
<td><input type="text" name="Fname" /></td>
</tr>
<tr align="left" valign="top">
<td>Last Name:</td>
<td><input type="text" name="Lname" /></td>
</tr>
<tr align="left" valign="top">
<td></td>
<td><input type="submit" name="submit" value="submit"
class="fb8" /></td>
</tr>
</table>
</form>
</body>
</html>
查找学生
学生证：
标题：
名字：
姓氏：
package org.cms.controller;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.cms.model.StudentDAO;
/**
* Servlet implementation class ListStudent
*/
@WebServlet("/LookupStudentServlet")
public class LookupStudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
String fnameOperator = request.getParameter("fnameOperator");
//System.out.println(fnameOperator);
String fname = request.getParameter("fname");
String condition = "where 1=1 ";
if (fname!=null||fname.length()>0) {
if (fnameOperator.equalsIgnoreCase("Eq")) {
condition =condition+ "and first_name = '"+fname+"'";
}
else if (fnameOperator.equalsIgnoreCase("Sw")) {
condition =condition+ "and first_name like '"+fname+"%'";
}
else if (fnameOperator.equalsIgnoreCase("Ew")) {
condition =condition+ "and first_name like '%"+fname+"'";
}
else if (fnameOperator.equalsIgnoreCase("Co")) {
condition =condition+ "and first_name like '%"+fname+"%'";
}
}
//System.out.println(condition);
StudentDAO student = new StudentDAO();
List<StudentDAO> students = student.lookupStudent(condition);
request.setAttribute("studentList", students);
} catch (SQLException sqle) {
request.setAttribute("error", "Retrieving Students failed.");
sqle.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
}
finally {}
request.getRequestDispatcher("LookupStudent.jsp").forward(request, response);
}
}
package org.cms.controller;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.cms.model.StudentDAO;
/**
* Servlet implementation class ListStudent
*/
@WebServlet("/UpdateStudentServlet")
public class UpdateStudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
int studentID;
studentID = Integer.parseInt(request.getParameter("StudentID"));
//System.out.println(fnameOperator);
String condition = "where 1=1";
condition = condition+"and student_id = "+studentID;
System.out.println(condition);
StudentDAO student = new StudentDAO();
List<StudentDAO> students = student.lookupStudent(condition);
request.setAttribute("studentList", students);
} catch (SQLException sqle) {
request.setAttribute("error", "Retrieving Students failed.");
sqle.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
}
finally {}
request.getRequestDispatcher("UpdateStudent.jsp").forward(request, response);
}
}
package org.cms.controller；
导入java.io.IOException；
导入java.sql.SQLException；
导入java.util.List；
导入javax.servlet.ServletException；
导入javax.servlet.annotation.WebServlet；
导入javax.servlet.http.HttpServlet；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpServletResponse；
导入org.cms.model.StudentDAO；
/**
*Servlet实现类ListStudent
*/
@WebServlet（“/UpdateStudentServlet”）
公共类UpdateStudentServlet扩展了HttpServlet{
私有静态最终长serialVersionUID=1L；
/**
*@请参阅HttpServlet#doPost（HttpServletRequest请求，HttpServletResponse响应）
*/
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
试一试{
国际学生；
studentID=Integer.parseInt（request.getParameter（“studentID”）；
//System.out.println（fnameOperator）；
字符串条件=“其中1=1”；
条件=条件+”和学生id=“+studentID”；
系统输出打印项次（条件）；
StudentDAO student=新StudentDAO（）；
session.setAttribute("name", object)
(String)session.getAttribute("name")