Servlet Programs
1) Write a servlet to calculate sum of 1 to n. Accept n from html file.
HTML:
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form action="SumServlet">
<pre>
Enter any number: <input type="text" name="t1"/>
<input type="submit" value="Sum"/>
</pre>
</form>
</body>
</html>
SERVLET:
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/**
* Servlet implementation class SumServlet
*/
public class SumServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public SumServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html");
PrintWriter out = response.getWriter();
int n = Integer.parseInt(request.getParameter("t1"));
int sum = 0;
for(int i=1; i<=n; i++ ) {
sum = sum + i;
}
out.println("<h1>Sum of first </h1>" +n+ " number is "+ sum);
}
}
2) Write a servlet that accepts single-valued (Name, Mobile No.) as well as multi-valued (Languages known, Hobbies) parameters like check boxes and multiple selection list boxes from an HTML document and outputs them to the screen.
CODE:
HTML:
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form action=MultiServlet>
<pre>
ENTER NAME: <input type="text" name="t1"/>
ENTER MOBILE: <input type="text" name="t2"/>
LANGUAGES KNOWN: <input type="checkbox" name="lng" value="English"/>ENGLISH
<input type="checkbox" name="lng" value="HINDI"/>HINDI
<input type="checkbox" name="lng" value="MARATHI"/>MARATHI
YOUR HOBBIES:
<select multiple="multiple" name="hob">
<option>CRICKET</option>
<option>CODING</option>
<option>SPEEDCUBING</option>
<option>READING</option>
<option>GYM</option>
</select>
<input type="submit" />
<input type="reset" />
</pre>
</form>
</body>
</html>
SERVLET:
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/**
* Servlet implementation class MultiServlet
*/
public class MultiServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public MultiServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String n = request.getParameter("t1");
String m = request.getParameter("t2");
String[] hobbies = request.getParameterValues("hob");
String[] langs = request.getParameterValues("lng");
String msg = "<h1> Your Details are:<br><hr> Name: "+n+" <br> Mobile: "+m;
msg += "<br>Hobbies:<br>";
for(String h: hobbies) {
msg+=h+",";
}
msg+="<br>Languages:<br>";
for(String h: langs) {
msg+=h+",";
}
out.println(msg);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
3)Aim: Write a servlet that accepts user name and password sent from an html file. If the password equals "secret", the servlet redirects the output to welcome.html or if the password is wrong then it redirects to error.html.
CODE:
Input.jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form action="LoginServlet" method="post">
<pre>
Enter UserName: <input type="text" name="t1"/>
Enter Password: <input type="text" name="t2"/>
<input type="submit" value="Login" /> <input type="reset"/>
</pre>
</form>
</body>
</html>
Logout.jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1> You have logged out</h1>
</body>
</html>
Error.jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1> Wrong Password or username. </h1>
</body>
</html>
Success.jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%
if(session.getAttribute("uname")==null){
response.sendRedirect("input.jsp");
}
%>
<h1>
Hey <%=session.getAttribute("uname") %>
<br>
Login Successful....
</h1>
<br><br>
<form action="Logout.jsp">
<input type="submit" value="Logout"/>
</form>
</body>
</html>
LoginServlet.java:
import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;
import java.io.IOException;
import java.io.PrintWriter;
/**
* Servlet implementation class LoginServlet
*/
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public LoginServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
PrintWriter out = response.getWriter();
String n = request.getParameter("t1");
String pwd = request.getParameter("t2");
response.setContentType("text/html");
if(n.equals("Atiq") && pwd.equals("Ehacker1#")) {
HttpSession hs = request.getSession();
hs.setAttribute("uname", n);
response.sendRedirect("success.jsp");
}
else {
out.println("<font color=red size=14 face=verdana> sorry wrong Password");
RequestDispatcher rd = request.getRequestDispatcher("Error.jsp");
rd.include(request, response);
}
}
}
4) Write a servlet which allow user to add new record to table login. Accept values of username and password from html file.
CODE:
Insert.html
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form action="JdbcServlet" method="post">
<h2 >Registration form</h2><hr>
<table>
<tr>
<td>Name</td>
<td><input type="text" name="Name" required /></td>
</tr>
<tr>
<td>Password</td>
<td><input type="password" name="Pass" required /></td>
</tr>
<tr>
<td>Favorite Language</td>
<td><input type="text" name="Lang" required /></td>
</tr>
<tr>
<td><input type="reset" value="Clear"/></td>
<td><input type="submit" value="ADD"/></td>
</tr>
</table>
</form>
</body>
</html>
Success.html:
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1>ONE RECORD ADDED</h1>
<form action="insert.html">
<input value="ADD ANOTHER" type="submit"/>
</form>
</body>
</html>
JdbcServlet.java:
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
/**
* Servlet implementation class JdbcServlet
*/
public class JdbcServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public JdbcServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String name = request.getParameter("Name");
String pass = request.getParameter("Pass");
String lang = request.getParameter("Lang");
try {
Class.forName("com.mysql.cj.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/batch2","root","Ehacker1#");
System.out.println("Connection created");
PreparedStatement ps = con.prepareStatement("insert into Jsp values(?,?,?);");
ps.setString(1, name);
ps.setString(2, pass);
ps.setString(3, lang);
int i = ps.executeUpdate();
if(i>0) {
response.sendRedirect("success.html");
}
}
catch (Exception e1) {
e1.printStackTrace();
}
out.close();
}
}
Reviewed by Asst. Prof. Sunita Rai
on
March 27, 2022
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