Java Techies - Solution for All
Servlet Examples
Example of First Servlet
Example of Annotation in Servlet
Example of Login Form
Example of Filter
Example of Config and Context
Example of First Servlet
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class FirstServlet extends HttpServlet
{
public void doGet(HttpServletRequest req,
HttpServletResponse res)
throws ServletException, IOException
{
PrintWriter pw = res.getWriter();
pw.println("Hello Client !IT IS SERVLET FIRST EXAMPLE ");
pw.close();
}
}
web.xml
<?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_3_0.xsd" version="3.0" metadata-complete="true"> <servlet> <servlet-name>FS</servlet-name> <servlet-class>FirstServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>FS</servlet-name> <url-pattern>/FirstServlet</url-pattern> </servlet-mapping> </web-app>Output
Hello Client !IT IS SERVLET FIRST EXAMPLE
Example of Annotation in Servlet
Example of Annotation in Servlet
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/Annotation_Demo")
public class Annotation_Demo extends HttpServlet
{
protected void doGet(HttpServletRequest request,
HttpServletResponse resp)
throws ServletException, IOException
{
PrintWriter pw = resp.getWriter();
pw.println("Hello Client ! ");
pw.close();
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
this.doGet(request, response);
}
}
Output
Example of Login Form
Example of Login Form
Login Page.php
LoginServlet.javaLogin Login Form
package com.ducat.login;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet
{
protected void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
this.doPost(request, response);
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
String w = null;
String userid = request.getParameter("txtUserid");
String password = request.getParameter("txtPwd");
if(userid.equals(password))
{
response.sendRedirect("welcome.php");
}
else
{
response.sendRedirect("invalid.php");
}
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>ServletDemo2</display-name> <servlet> <servlet-name>LoginServlet</servlet-name> <servlet-class>com.ducat.login.LoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/login</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>/Login.php</welcome-file> </welcome-file-list> </web-app>invalid.php
<head>Welcome.phpInvalid Page </head>Invalid userid and password , Please Try Again
<head>OutputWelcome Page </head>Welcome User
Example of Filter
Example of Filter
HelloServlet.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloServlet extends HttpServlet
{
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.print("welcome to servlet");
}
}
MyFilter.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.*;
public class MyFilter implements Filter
{
public void init(FilterConfig arg0)
throws ServletException
{
}
public void doFilter(ServletRequest req,
ServletResponse resp, FilterChain chain)
throws IOException, ServletException
{
PrintWriter out=resp.getWriter();
out.print("filter is invoked before");
chain.doFilter(req, resp);
//sends request to next resource
out.print("filter is invoked after");
}
public void destroy()
{
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" 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"> <servlet> <servlet-name>HelloServlet</servlet-name> <servlet-class>HelloServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>HelloServlet</servlet-name> <url-pattern>/servlet1</url-pattern> </servlet-mapping> <filter> <filter-name>f1</filter-name> <filter-class>MyFilter</filter-class> </filter> <filter-mapping> <filter-name>f1</filter-name> <url-pattern>/servlet1</url-pattern> </filter-mapping> </web-app>
Example of Config and Context
Example of Config and Context
ConfigDemo.java
package com.ducat.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class ConfigDemo
*/
public class ConfigDemo extends HttpServlet
{
public void init(ServletConfig config)
throws ServletException
{
super.init(config);
}
protected void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
ServletConfig sc = this.getServletConfig();
String jdbcDriverName =sc.getInitParameter("jdbc");
String dsnName = sc.getInitParameter("dsnName");
PrintWriter pw = response.getWriter();
pw.println("Inside ConfigDemo Servlet ");
pw.println("JDBC Driver Name "+jdbcDriverName);
pw.println("DSN Name "+dsnName);
ServletContext ss = sc.getServletContext();
pw.println("Email is"+ss.getInitParameter("email"));
pw.close();
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{}
}
ConfigServlet2.java
package com.ducat.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class ConfigServlet2
*/
public class ConfigServlet2 extends HttpServlet
{
public void init(ServletConfig config)
throws ServletException
{
super.init(config);
}
protected void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
ServletConfig sc = this.getServletConfig();
String jdbcDriverName =sc.getInitParameter("jdbc");
String dsnName = sc.getInitParameter("dsnName");
PrintWriter pw = response.getWriter();
pw.println("Inside Config Servlet2");
pw.println("JDBC Driver Name:-"+jdbcDriverName);
pw.println("DSN Name :-"+dsnName);
pw.println("Email is:- "+this.getServletConfig()
.getServletContext().getInitParameter("email"));
pw.close();
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
// TODO Auto-generated method stub
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <context-param> <param-name>email</param-name> <param-value>jtechies@jtechies.com</param-value> </context-param> <servlet> <servlet-name>ConfigDemo</servlet-name> <servlet-class>com.ducat.servlet.ConfigDemo</servlet-class> <init-param> <param-name>jdbc</param-name> <param-value>sun.jdbc.odbc.JdbcOdbcDriver</param-value> </init-param> <init-param> <param-name>dsnName</param-name> <param-value>FirstDSN</param-value> </init-param> </servlet> <servlet> <servlet-name>ConfigServlet2</servlet-name> <servlet-class>com.ducat.servlet.ConfigServlet2</servlet-class> </servlet> <servlet-mapping> <servlet-name>ConfigDemo</servlet-name> <url-pattern>/ConfigDemo</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>ConfigServlet2</servlet-name> <url-pattern>/ConfigServlet2</url-pattern> </servlet-mapping> </web-app>Output
