Java ArrayList class cast exception when trying to set an member variable for an instance of a class -


hi have been stuck on error past 3 hours , slap myself when figures out wrong. trying set arraylist instance of teacheraccount class. keep getting below error when running simplest test think can below.

here teacheraccount class

package com.studentorganizer;   import java.util.list;  public class teacheraccount {      private string username;     private string password;     private list<string> students;      public teacheraccount(){         username=null;         password=null;         students = null;      }     public teacheraccount(string username, string password,list<string> students){         this.username = username;         this.password = password;         this.students = students;     }      public void setusername(string username){         this.username = username;     }      public void setpassword(string password){         this.password = password;     }      public void setstudents(list<string> students){         this.students = students;       }      public string getusername(){         return username;     }      public string getpassword(){         return password;     }      public list<string> getstudents() {         return students;       } }

and here small test running produces error

            teacheraccount currentteach = new teacheraccount();         list<string> tempstu = new arraylist<string>();         tempstu.add("hi");         tempstu.add("hi again");         currentteach.setstudents(tempstu);

i have narrowed down the problem being setstudents. tempstu , students both of type list appreciated. thanks

edit here jsp file requested:

    <%@ page language="java" contenttype="text/html; charset=iso-8859-1"     pageencoding="iso-8859-1"%> <!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd"> <% string currentusername = (string)request.getattribute("currentusername"); %> <% string currentpassword = (string)request.getattribute("currentpassword"); %> <% string students = (string)request.getattribute("students"); %> <html> <head> <meta http-equiv="content-type" content="text/html; charset=iso-8859-1"> <link rel="stylesheet" href="css/style.css"> <script src="js/studentorganizer.js" type="text/javascript"></script> <script src="js/jquery-1.10.2.min.js"></script> <title>student organization home page</title>  </head> <body> <form action=""> <div class='header'>student organization home page - welcome <%=currentusername%>!</div> </form>   <br>  <div>test jsp vars <%=currentusername%> pass: <%=currentpassword%> students: <%=students%></div>  <form method="link" action="jsp/students.jsp">     <select>         <option selected>class 1</option>         <option selected>class 2</option>         <option selected>class 3</option>         <option selected>class 4</option>     </select>     <input type="submit" value="go students!">     </form> </body>  </html>   [error   ] srve0777e: exception thrown application class 'com._jsp._homepage._jspservice:98' java.lang.classcastexception: java.util.arraylist cannot cast java.lang.string     @ com._jsp._homepage._jspservice(_homepage.java:98)     @ com.ws.jsp.runtime.httpjspbase.service(httpjspbase.java:101)     @ javax.servlet.http.httpservlet.service(httpservlet.java:668)     @ [internal classes]     @ com.ws.jsp.webcontainerext.abstractjspextensionservletwrapper.handlerequest(abstractjspextensionservletwrapper.java:215)     @ com.ws.webcontainer.filter.webappfiltermanager.invokefilters(webappfiltermanager.java:1033)     @ [internal classes]     @ com.studentorganizer.login.doget(login.java:93)     @ javax.servlet.http.httpservlet.service(httpservlet.java:575)     @ [internal classes]  [err] java.lang.classcastexception: java.util.arraylist cannot cast java.lang.string [err]   @ com._jsp._homepage._jspservice(_homepage.java:98) [err]   @ com.ws.jsp.runtime.httpjspbase.service(httpjspbase.java:101) [err]   @ javax.servlet.http.httpservlet.service(httpservlet.java:668) [err]   @ [internal classes]

i'm not strong in jsp clear me , try show students in jsp file single string. students defined list. please, run in loop in jsp file on students.

something like:

<% arraylist<string> students = teacheraccount .getstudents();     iterator<string> iterator = students .iterator();      while (iterator.hasnext())     {       string student = (string)iterator.next();       string pid = string.getid();       ... %>

suppose problem here:

<div>test jsp vars <%=currentusername%>  pass: <%=currentpassword%> students: <%=students%></div>                                            ^^^^

use foreach instead show it


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