Update Employee Records

In this Example we can Add and Update the Details of Employee using Servlet. We create four file employee.jsp, viewdata.jsp, EmployeeAdd.java and viewdata.java. When a web page ("employee.jsp") run on browser then it will called to Servlet ("EmployeeAdd.java") and add the new Employee Record in the database and provide a link on browser, by this link user redirect to Servlet "viewdata". This Servlet retrieves the data and show on browser.

Step 1: Source code of employee.jsp to add and update the Employee records.

<%@page import="java.sql.*"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
 <HEAD>
  <TITLE> New Document </TITLE>
  <META NAME="Generator" CONTENT="EditPlus">
  <META NAME="Author" CONTENT="">
  <META NAME="Keywords" CONTENT="">
  <META NAME="Description" CONTENT="">
  <style>
  .tdcls{
  font-weight:bold;
}
A:visited  
{color: #00000;font-weight:bold; text-decoration: underline}
A:link  {color: #FFC0C0; text-decoration: none}
A:active  {color: #C0FFC0; text-decoration: none}
A:hover   { color: #FF0000;  text-decoration: none}
  </style>
 </HEAD>
 <BODY>
 <br><br> 
 <form name="frm" action="empsave" method="post">
 <%
 String emp_id = "";
 String first_name = "";
 String last_name = "";
 String request_status = "";
 String pend_request_type="";
 String pend_request_date="";
 String pend_request_data="";
 String readonly="";
 String  bttn_value="Add";
 int pend_request_id = 0;
if(request.getParameter("emp_id")!=null 
  && request.getParameter("emp_id")!="")
 {
    emp_id= request.getParameter("emp_id").toString();
 pend_request_id= Integer.parseInt
(request.getParameter("pend_request_id").toString());
   readonly = "readonly";
    Connection conn = null;
    String url = "jdbc:mysql://localhost:3306/";
    String dbName = "user_register";
    String driver = "com.mysql.jdbc.Driver";
    String userName = "root"; 
    String password = "root";
	bttn_value = "Update"; 
	Statement st;	 
    try {
      Class.forName(driver).newInstance();
      conn = DriverManager.getConnection
       (url+dbName,userName,password);
      System.out.println("Connected to the database");
      String query1 = 
       "SELECT * from pend_requests where emp_id='"+emp_id+"' 
        and pend_request_id='"+pend_request_id+"'";
	String query2 = "SELECT * from employee_details "+
        "where eid='"+emp_id+"'";
	  st = conn.createStatement();	
		ResultSet rs1 = st.executeQuery(query1);
		while(rs1.next())
		{
			 request_status = rs1.getString(1);
             pend_request_type=rs1.getString(5);
            pend_request_date=rs1.getString(6);
            pend_request_data=rs1.getString(7);			
		}
	ResultSet rs2 = st.executeQuery(query2);
	while(rs2.next())
	   {
             first_name = rs2.getString(2);
             last_name = rs2.getString(3);			 
		}		
	}
	catch (Exception e) {
      e.printStackTrace();
    }
 }
   %>
   <input type="hidden"  name="pid" value="<%=pend_request_id%>">
  <table width="350" align="center" border=0 bgcolor=#3EA99F>
  <tr><td colspan=2 align="center" class="tdcls">
   Employee Details</td></tr>
   <tr>
    <td width="150px" class="tdcls">Employee Id</td>
    <td width="200px">
<input type="text" name="emp_id" value="<%=emp_id%>" 
 <%=readonly%>></td></tr> 
   <tr>
    <td class="tdcls">First Name</td>
  <td><input type="text" name="first_name" 
  value="<%=first_name%>"></td> </tr><tr>
   <td class="tdcls">Last Name</td>
<td><input type="text" name="last_name" 
 value="<%=last_name%>"></td>
  </tr> 
	     <tr><td class="tdcls">Request Status</td>
		<td><select name="request_status">
<option value="open"  <% 
if(request_status.equals("open"))out.println("selected");
%>>Open</option>
 <option value="pending" <%
 if(request_status.equals("pending"))out.println("selected");
%>>Pending</option>
  <option value="deferred"  <% 
if(request_status.equals("deferred"))out.println("selected");
%>>Deferred</option>
   <option value="closed" <% 
if(request_status.equals("closed"))out.println("selected");
%>>Closed</option>
	</select>
	</td></tr>
	<tr>
         <td class="tdcls">Request Type</td>
       <td><select name="pend_request_type">
      <option value="admin" <%
   if(pend_request_type.equals("admin"))out.println("selected");
%>>Admin</option>
	  <option value="user" <% 
if(pend_request_type.equals("user"))out.println("selected");
%>>User</option>
		</select>
      
		 </td></tr> 
		 <tr>
            <td class="tdcls">Date (yyyy-mm-dd)</td>
    <td>
  <input type="text" name="pend_request_date"
 value="<%=pend_request_date%>"  <%=readonly%>>
</td>
         </tr> 
		  <tr><td class="tdcls">Description</td>
           <td>
<input type="text" name="pend_request_data" 
value="<%=pend_request_data%>"></td></tr>
     <tr>
<td colspan=2 align="center">
<input type="submit" name="submit" value="<%=bttn_value%>">
</td></tr></table>
	<br><br>
	<%
	 if(!(request.getParameter("emp_id")!=null 
           && request.getParameter("emp_id")!=""))
           {
	 %>
	<table width="100%" align="center">
	   <tr>
          <td  align="center"><a href="viewdata">
     Click here To show all records</a></td>
</tr>
    </table>
	<%
 }
	 %>
	        
 </BODY>
</HTML>

Step 2:Source code of Servlet (EmployeeAdd.java) to add and update the data.


import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import javax.sql.*;

import java.sql.*;

import java.util.*;

import java.text.*;



public class EmployeeAdd extends HttpServlet{ 

 

 public void doPost(HttpServletRequest request, 

  HttpServletResponse response)

	  throws ServletException,IOException{

  response.setContentType("text/html");

  PrintWriter out = response.getWriter();



 System.out.println("MySQL Connect Example.");

  Connection conn = null;

  String url = "jdbc:mysql://localhost:3306/";

  String dbName = "user_register";

  String driver = "com.mysql.jdbc.Driver";

  String userName = "root"; 

  String password = "root";

  String emp_id = request.getParameter("emp_id"); 

  String first_name = request.getParameter("first_name");

  String last_name = request.getParameter("last_name");

  String request_status = request.getParameter("request_status");

  String pend_request_date = request.getParameter("pend_request_date");

  String pend_request_type = request.getParameter("pend_request_type");

  String pend_request_data = request.getParameter("pend_request_data");

  int pend_request_id =  Integer.parseInt(request.getParameter("pid"));

  String bttn_value = request.getParameter("submit");

  String ardate[] = pend_request_date.split("-");



 if(ardate.length!=3)

 {

  response.sendRedirect("employee.jsp");

 }

  

  Statement st;

  

  try {



  java.util.Date date = new java.util.Date();

  Class.forName(driver).newInstance();

  conn = DriverManager.getConnection(url+dbName,userName,password);

  System.out.println("Connected to the database");

  int j=0;

  int i=0;

  if(bttn_value.equals("Add"))

  {

  String query_1 = "insert into employee_details set eid='"+

   emp_id+"',first_name='"+first_name+"',

  
last_name='"+last_name+"'";

  out.println("query_1 " + query_1);

  out.println("<br>");

  st = conn.createStatement();

  i = st.executeUpdate(query_1);

  out.println("<br>");

 
out.println("i " + i);

  String query_2 =

		"insert into pend_requests set pend_request_status='"+request_status+"',

emp_id='"+emp_id+"',pend_request_type='"+pend_request_type+"',

	pend_request_date='"+pend_request_date+"',

pend_request_data='"+pend_request_data+"'";

  out.println("query_2 " + query_2);

 out.println("<br>");

  st = conn.createStatement();

 j = st.executeUpdate(query_2);

 response.sendRedirect("viewdata");

  }

  else if(bttn_value.equals("Update"))

  {

 java.util.Date now = new java.util.Date();

  String DATE_FORMAT = "yyyy-MM-dd hh:mm:ss";

 SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);

  String strDateNew = sdf.format(now) ;

  String query_1 = 

 
"update  employee_details set first_name='"+first_name+"',

  last_name='"+last_name+"' 

 
where eid='"+emp_id+"'";

   out.println("query_1 " + query_1);

 out.println("<br>");

 st = conn.createStatement();

   i = st.executeUpdate(query_1);

 out.println("<br>");

  
out.println("i " + i);

  String query_2 = 

"update pend_requests set pend_request_status='"+request_status+"',

emp_id='"+emp_id+"',pend_request_type='"+pend_request_type+"',

	pend_request_date='"+pend_request_date+"',

pend_request_data='"+pend_request_data+"',

	respond_date='"+strDateNew+"' where pend_request_id="+

	pend_request_id+" and emp_id='"+emp_id+"'";

  out.println("query_2 " + query_2);

 out.println("<br>");

  st = conn.createStatement();

 j = st.executeUpdate(query_2);

 response.sendRedirect("viewdata");

  } 

  //  pw.println(query);

  conn.close();

  System.out.println("Disconnected from database");

  } catch (Exception e) {

 response.sendRedirect("viewdata");

  e.printStackTrace();

  }

  }

}

Step 3:Source code of Servlet (viewdata.java) to retrieve the data.


import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import javax.sql.*;

import java.sql.*;

import java.util.*;



public class viewdata extends HttpServlet{ 

 

 public void doGet(HttpServletRequest request,

		  HttpServletResponse response)

	    throws ServletException,IOException{

  response.setContentType("text/html");

  PrintWriter pw = response.getWriter();



 System.out.println("MySQL Connect Example.");

  Connection conn = null;

  String url = "jdbc:mysql://localhost:3306/";

  String dbName = "user_register";

  String driver = "com.mysql.jdbc.Driver";

  String userName = "root"; 

  String password = "root";

  String respond_date="";

  Statement st;

  ArrayList arData=null;

  ArrayList arDataList=new ArrayList();

 HttpSession session=request.getSession(true);

  try {

  Class.forName(driver).newInstance();

  conn = DriverManager.getConnection

  (url+dbName,userName,password);

	  System.out.println("Connected to the database");

  String query = 

 
"SELECT p1.pend_request_id,p1.emp_id,p1.pend_request_type,"+

  "p1.pend_request_date,p1.pend_request_status,"+

  "p1.pend_request_data,p2.first_name,p2.last_name,"+

  "p1.respond_date FROM pend_requests p1,"+

  "employee_details p2 where p1.emp_id=p2.eid"; 

  st = conn.createStatement();  

  ResultSet rs = st.executeQuery(query);  

  while(rs.next())

  {

 arData=new  ArrayList();

 System.out.println(rs.getString(9));

 pw.println(rs.getString(9));

	  if(rs.getString(9)==null)

  {

  respond_date = "Not Responding";

  }

  else

  {

  respond_date = rs.getString(9);

  }

  arData.add(rs.getInt(1));

  arData.add(rs.getString(2));

  arData.add(rs.getString(7));

  arData.add(rs.getString(8));

  arData.add(rs.getString(5));

  arData.add(rs.getString(3));

  arData.add(rs.getString(4));

  arData.add(respond_date);

  

  arDataList.add(arData);

  }

  

 pw.println("query4 " + query);

  pw.println("<br>");

	  session.setAttribute("arDataList",arDataList);

  
pw.println("arData " + arData);

  
pw.println("<br>");

  
pw.println("arDataList " + arDataList);

  
pw.println("<br>");

  
pw.println("session "+ session.getAttribute("arDataList"));

  
pw.println("<br>");

 response.sendRedirect("viewdata.jsp");

  //  pw.println(query);

  conn.close();

  System.out.println("Disconnected from database");

  } catch (Exception e) {

  response.sendRedirect("viewdata.jsp");

  e.printStackTrace();

  }

  }

}

Step 4: Mapping the servlet (timer.java) in to web.xml file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">

<display-name>Welcome to Tomcat</display-name>
<description>
Welcome to Tomcat
</description>
<servlet>
<servlet-name>viewData</servlet-name>
<servlet-class>viewdata</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>viewData</servlet-name>
<url-pattern>/viewdata</url-pattern>
</servlet-mapping>

<servlet>
<servlet-name>empSave</servlet-name>
<servlet-class>EmployeeAdd</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>empSave</servlet-name>
<url-pattern>/empsave</url-pattern>
</servlet-mapping>

<servlet>
<servlet-name>empUpdate</servlet-name>
<servlet-class>EmpUpdate</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>empUpdate</servlet-name>
<url-pattern>/empupdate</url-pattern>
</servlet-mapping>

</web-app>

Step 5: To create a web page (viewdata.jsp) to show all the records.

<%@page import="java.util.*"%>
<html>
<head>
<title>Employee request form</title>
<style>
A:visited {color: #00000;font-weight:bold; text-decoration: underline}
A:link {color: #FFC0C0; text-decoration: none}
A:active {color: #C0FFC0; text-decoration: none}
A:hover { color: #FF0000; text-decoration: none}
.loginhead1{
text-align:left;
padding-left:5px;
}
</style>
</head>
<body>
<center>
<table border="1" width="800px" cellspacing="0"
cellpadding="0" bgcolor="bluelight">
<tr>
<td width="10%" class="loginhead1" align="center"><b>Emp ID</b></td>
<td width="19%" class="loginhead1" align="center"><b>Name</b></td>
<td width="10%" class="loginhead1" align="center"><b>Request</b></td>
<td width="14%" class="loginhead1" align="center"><b>Type</b></td>
<td width="19%" class="loginhead1" align="center"><b>
Request Date</b></td>
<td width="20%" class="loginhead1" align="center"><b>
Received Date</b></td>
<td width="11%" class="loginhead1" align="center" height="25px"><b>
Status</b></td>
<td width="11%" class="loginhead1" align="center" height="25px"><b>
Update</b></td>
</tr>
<%
String ename="";
ArrayList arList=null;
ArrayList AdminPendrequest = (ArrayList)session.getAttribute("arDataList");
//out.println(AdminPendrequest);
out.println("<br>");
int count=0;

if(AdminPendrequest!= null){
for(int i=0;i<AdminPendrequest.size();i++)
{
count++;
arList = (ArrayList)AdminPendrequest.get(i);

int pend_request_id = Integer.parseInt((arList.get(0).toString()));
String emp_id =arList.get(1).toString();
String first_name = arList.get(2).toString();
String last_name = arList.get(3).toString();
String request_status = arList.get(4).toString();
String request_type = arList.get(5).toString();
String request_date = arList.get(6).toString();
String respond_date = arList.get(7).toString();
ename = first_name+ " " + last_name;%>
<tr><form name="frm" method="post" action="employee.jsp">
<input type="hidden" name="emp_id" value="<%=emp_id%>">
<input type="hidden" name="pend_request_id" value="<%=pend_request_id%>">
<td width="10%" class="loginhead1" align="center"><%=emp_id%></td>
<td width="19%" class="loginhead1" align="center"><%=ename%></td>
<td width="10%" class="loginhead1" align="center"><%=request_status%></td>
<td width="14%" class="loginhead1" align="center"><%=request_type%></td>
<td width="19%" class="loginhead1" align="center"><%=request_date%></td>
<td width="20%" class="loginhead1" align="center"><%=respond_date%></td>
<td width="11%" class="loginhead1" align="center" height="25px">
<select name="request_status">

<%
if(request_status.equals("open"))
{
%>
<option value="pending">pending</option>
<option value="deferred">Deferred</option>
<option value="closed">Closed</option>
<%
}
else if(request_status.equals("pending"))
{
%>
<option value="deferred">Deferred</option>
<option value="closed">Closed</option>
<%
}
else if(request_status.equals("deferred"))
{%>
<option value="pending">Pending</option>
<option value="closed">Closed</option>

<%}
else
{
%>
<option value="closed">Closed</option>
<%
}

%>
</select>
</td>
<td width="19%" class="loginhead1" align="center">
<input type="submit" name="submit" value="Update"</td>
<%
%>
</tr>
</form>
<%
}
}
%>
</table>
<br>
<br>
<table>
<tr><td align="center">
<a href="employee.jsp">Add More Employee</a></td></tr>
</table>
</center>
</body>
</html>

Step 5: Start tomcat and type http://localhost:8080/updaterequest/employee.jsp in on the browser and Click on Text Link "Click here To Show all records" . Your browser should display all the records..

Successful Output of the program: