username availability using ajax

pls help me tell whats wrong
here is the code of my files
i am a total newbie......pls
t.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" language="javascript" src="ah.js"></script>
</head>
<body>
<table>
<tr>
        <td width="36%">Userid j</td>
        <td width="33%">
            <form name="f1" >
          <input type="text" name="user"  onBlur="startRequest()"/>
          
          
          <input type="button" name="btn" value="click" onClick="startRequest()" /></form>
          
        </td>
        <td width="31%" id="results">&nbsp;</td>
    </tr>
</table>

</body>
</html>

ah.js

var xmlHttp;// global instance of XMLHttpRequest
function createXmlHttpRequest()
{
       if(window.ActiveXObject)
       {
        xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
      }

    else if(window.XMLHttpRequest)
    {
        xmlHttp=new XMLHttpRequest();
        
     }

}

function startRequest()
{

  createXmlHttpRequest();
alert("hi4");
  var u1=document.f1.user.value;
  alert("hi");
  xmlHttp.open("GET","http://localhost:8080/ajax/Jas?user="+u1 ,true)
  alert("hi2");
  xmlHttp.onreadystatechange=handleStateChange();
  alert("hi3");
  xmlHttp.send(null);

}

function handleStateChange()
{alert("handle" );

    if(xmlHttp.status==200)
    { alert("ready");
        if(xmlHttp.readyState==4)
            {alert("status ok");
          var message =  xmlHttp.responseXML.getElementsByTagName("valid")[0].childNodes[0].nodeValue;

             document.getElementById("results").innerHTML=message;
            }
        else
        {
           alert("Error loading pagen"+ xmlHttp.status +
":"+xmlHttp.statusText);
        }
    }
}

UserOp.java

import java.sql.*;
import java.util.*;
public class UserOp {
public boolean containsKey(String a)
{
	String urlPrefix = "jdbc:db2://localhost:50000/";
	String url;
	//String user;
	String empNo; 
	Connection con;
	Statement stmt;
	ResultSet rs;
	ArrayList<String> al=new ArrayList<String>();
	System.out.println ("**** Enter class EzJava");


	url = urlPrefix + "PRAC";

	try
	{
	// Load the driver
	Class.forName("com.ibm.db2.jcc.DB2Driver");
	System.out.println("**** Loaded the JDBC driver");
	// Create the connection using the IBM Data Server Driver for JDBC and SQLJ
	con = DriverManager.getConnection (url,"db2inst1","1491");
	// Commit changes manually
	con.setAutoCommit(false);
	System.out.println("**** Created a JDBC connection to the data source");
	// Create the Statement
	stmt = con.createStatement();
	System.out.println("**** Created JDBC Statement object");
	// Execute a query and generate a ResultSet instance
	rs = stmt.executeQuery("SELECT * FROM USERS"); 
	System.out.println("**** Created JDBC ResultSet object");
	// Print all of the employee numbers to standard System.output device
	while (rs.next()) {
	empNo = rs.getString(2);
	al.add(empNo);
	System.out.println("Employee number = " + empNo);
	}
	System.out.println("**** Fetched all rows from JDBC ResultSet");
	// Close the ResultSet
	rs.close();
	System.out.println("**** Closed JDBC ResultSet");
	// Close the Statement
	stmt.close();
	System.out.println("**** Closed JDBC Statement");
	// Connection must be on a unit-of-work boundary to allow close
	con.commit();
	System.out.println ( "**** Transaction committed" );
	// Close the connection
	con.close();
	System.out.println("**** Disconnected from data source");
	System.out.println("**** JDBC Exit from class EzJava - no errors");
	}
	catch (ClassNotFoundException e)
	{
	System.out.println("Could not load JDBC driver");
	System.out.println("Exception: " + e);
	e.printStackTrace();
	}
	catch(SQLException ex) 
	{
	System.err.println("SQLException information");
	while(ex!=null) {
	System.out.println ("Error msg: " + ex.getMessage());
	System.out.println ("SQLSTATE: " + ex.getSQLState());
	System.out.println ("Error code: " + ex.getErrorCode());
	ex.printStackTrace();
	ex = ex.getNextException(); // For drivers that support chained exceptions

	}
	}
	String ia[]=new String[al.size()];
	ia=al.toArray(ia);
	int c=(ia.length);
	boolean ab=false;
	System.out.println("sup"+a);
	for(int i=0;i<c;i++)
	{
		if(ia[i].equals(a))
			{
			ab=true;
			System.out.println("up"+ia[i]);
			}
		else
			{
			System.out.println(ia[i]);
			}
	}
	if(ab==true)
	{
		return true;
	}
	else
	{
	return false;
	}
}
public static void main(String q[])
{
	UserOp a=new UserOp();
System.out.println((a.containsKey("jas1291")));
		
}
}

Jas.java

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class for Servlet: Jas
 *
 */
 public class Jas extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
   static final long serialVersionUID = 1L;
   
    /* (non-Java-doc)
	 * @see javax.servlet.http.HttpServlet#HttpServlet()
	 */
	public Jas() {
		super();
	}   	
	
	/* (non-Java-doc)
	 * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String targetId = request.getParameter("user");
		System.out.print(targetId);
	       //check the id. If it is not existing already then return true else false
		UserOp userOp=new UserOp();

		
	           if ((targetId != null) && !userOp.containsKey(targetId.trim())) {
	            response.setContentType("text/xml");
	            response.setHeader("Cache-Control", "no-cache");
	            response.getWriter().write("<valid>true</valid>");
	        } else {
	            response.setContentType("text/xml");
	            response.setHeader("Cache-Control", "no-cache");
	            response.getWriter().write("<valid>false</valid>");
	        }

	}  	
	
	/* (non-Java-doc)
	 * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
	}   	  	    
}

jasleen12345

Newbie Poster

18 posts since Aug 2010

Reputation Points: 10

Solved Threads: 0

username availability using ajax

This article has been dead for over three months