Member Avatar for ronnieaka

i tested the php version of the autocomplete example in ajax using PHP from here:
http://www.w3schools.com/ajax/ajax_aspphp.asp

i tried the PHP veriosn, not the ASP version. It worked fine.

Now i want to implement the same thing in JSP, and so i translated the PHP version of source file (which has the 'suggestions' ) to JSP to my best effort

but still it doesn't work. i type in some letters, single only though just for testing, and no suggestion comes up, and when i directly run the JSP file, i get some errors


here is the ajaxexample.html code: 

<html>
<head>
<script type="text/javascript">
function showHint(str)
{
if (str.length==0)
  { 
  document.getElementById("txtHint").innerHTML="";
  return;
  }
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","gethint.jsp?q="+str,true);
xmlhttp.send();
}
</script>
</head
<body>

<p><b>Start typing a name in the input field below:</b></p>
<form> 
First name: <input type="text" onkeyup="showHint(this.value)" size="20" />
</form>
<p>Suggestions: <span id="txtHint"></span></p>

</body>
</html>

here is the JSP version of the PHP code you can see on the above link

<%@ page language="Java" %>

<%!  

String hint="";
String q;

String a[]={"AstonMartin","BobDylan","Catherine Zeta Jones", "Dog", "Eerie", "Faad" , "Great" , "Handsome" ,"Idiot" ,"Jasmine" ,"Kaminey" };


String responsse; // this will come up as suggestions
int i=0;
%>

<%
// Fill up array with names
 
q=request.getParameter("q");

if (q.length > 0)
  {
  hint="";
  for(i=0; i<11;i++)
    {
    if (q.toLowerCase().equals( a[i].substring(0,q.length).toLowerCase() ) )  
      {
      if (hint.equals(""))
        {
         hint= a[i];
        }
      else
        {
         hint= hint+" , "+ a[i];
        	
        } //if else block
      } //if after for loop
    }//for loop


//  } //outermost if


// Set output to "no suggestion" if no hint were found
// or to the correct values
if (hint.equals(""))
  {
   responsse="no suggestion";
  }
else
  {
   responsse= hint;
  }

//output the responsse
out.print(responsse); 
%>

the errors i'm getting when i directly run the JSP :

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /ajaxexample/exp/gethint.jsp at line 27

24: hint="";
25: for(i=0; i<11;i++)
26: {
27: if (q.toLowerCase().equals( a.substring(0,0).toLowerCase() ) ) //q.length
28: {
29: if (hint.equals(""))
30: {


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:553)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:457)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

java.lang.NullPointerException
org.apache.jsp.ajaxexample.exp.gethint_jsp._jspService(gethint_jsp.java:81)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

so tell me what is wrong in it or whether it is even possible to do this with JSP. i have to do this in JSP because in my project i need to provide suggestions in the search box,which needs to be simple and understandable

Edited by ronnieaka because: n/a
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Member Avatar for ronnieaka

ok people i got it working, if i comment lines 20, 21 and 40
and if i change line 25 with this:

if (q.toLowerCase().equals( a[i].substring(0,1).toLowerCase() ) )

basically, everywhere i call length to get a string's length, it was giving some exception. with that removed, i'm getting suggestions up to only the first letter compared with the provided 'suggestions'.
logically it should be compared upto that many number of letters as many are entered by the user, but here its working upto only first letter


so that if i enter "abc" it will first give Ashish as i type a but nothing when i further type b and c

so please find out why the hell length is not working, why its giving exceptions in jsp?! i have used it in many of my Swing projects to get user's entered data's length in database connected applications.

Edited by ronnieaka because: n/a
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