Hi I am new to java coding, i trying to create dynamic web page in eclipse. this is my demoServlet.java code
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
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("/demoServlet")
public class demoServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public demoServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out= response.getWriter();
out.println("<!DOCTYPE html PUBLIC \''>");
out.println("<html>");
out.println("<head>");
out.println("<script language=\'JavaScript\'>");
RequestDispatcher rd= request.getRequestDispatcher("/WEB-INF/javascript/Validate.js");
rd.include(request, response);
out.println("</script>");
out.println("</head>");
out.println("<body>");
out.println("<form action=\'/myWebprj/Success.jsp onSubmit=\'return Validateusername(this.username.value)\'>");
out.println("UserName: <input type=\'text\' name=\'username\'>");
out.println("<input type=\'submit\' value=\'Submit\'>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
this is my JSP page
<%# page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>My First jsp page in servlets</title>
</head>
<body>
Its Successfully completed
</body>
</html>
and this is my javascript page
function Validateusername(username)
{
var returnValue=true;
if(username=""){
alert("Enter username is empty");
returnValue=false;
}
return returnValue;
}
when i am trying to enter SUBMIT button its showing me the error
HTTP Status 404 - /myWebprj/Success.jsp%20onSubmit=
--------------------------------------------------------------------------------
type Status report
message /myWebprj/Success.jsp%20onSubmit=
description The requested resource is not available.
Can any one help me out . whats is the error in the code...?
Might it be possible that you are somehow accessing your demoServlet servlet using POST instead of GET? This would explain your error message. Please check your JavaScript console to make certain it is using GET.
Also, please modify your doPost() method to the following:
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
If this resolves the error, then we have the problem solved.
This works for me! I only have removed the return keyword from the onsubmit event attribute. I also have modified the code a bit to properly assign the username to the javascript function.
package test;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
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("/demoServlet")
public class demoServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public demoServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out= response.getWriter();
String username = request.getParameter("username");
out.println("<!DOCTYPE html PUBLIC \''>");
out.println("<html>");
out.println("<head>");
out.println("<script language=\'JavaScript\'>");
RequestDispatcher rd= request.getRequestDispatcher("/WEB-INF/javascript/Validate.js");
rd.include(request, response);
out.println("</script>");
out.println("</head>");
out.println("<body>");
/*
onSubmit should call only 'Validateusername()'
so the the 'return' keyword has been removed
*/
out.println("<form action=\'/Test/Success.jsp\' onSubmit=\'Validateusername(" + username + ")\'>");
out.println("UserName: <input type=\'text\' name=\'username\'>");
out.println("<input type=\'submit\' value=\'Submit\'>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
function Validateusername(username)
{
var returnValue=true;
if(username == undefined || username == null || username == ""){
alert("Enter username is empty");
returnValue=false;
}
return returnValue;
}
Your servlet code looks fine. The only change you need to make is in Validate.js file.
When validating username for empty you have used "=":
if(username=""){ // your code }
Instead you use "==", it works fine.
if(username==""){ // your code }
Related
I am having when using apache tomcat with java. The problem might be in the web.xml but I dont know how to fix it. This is my project explorer:
So the thing is that when I run registro.html everything goes as expected:
But when I click on enviar the 404 appears:
So this is my code in registro.html:
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Registro</title>
</head>
<body>
<form action="/Ejer2/Registro" method="POST">
<input type=hidden name=registro value=resultadoRegistro>
<BR><BR>Username: <input type=text name=user>
<BR><BR>Password: <input type=password name=pass>
<BR><BR><input type=submit value="Enviar"><input type=reset>
</form>
</body>
</html>
And this is my Registro.java:
package Ejer2;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.*;
#SuppressWarnings("deprecation")
#WebServlet(urlPatterns="/Registro")
public class Registro extends HttpServlet implements SingleThreadModel{
private static final long serialVersionUID = 1L;
public Registro() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
HttpSession session=req.getSession(true);
Usuario miuser=(Usuario)session.getValue(session.getId());
if(miuser==null){
miuser=new Usuario(req.getParameter("user"),req.getParameter("password"));
session.putValue(session.getId(),miuser);
}
res.setContentType("text/html");
String user=req.getParameter("user");
//String pass = req.getParameter("pass");
PrintWriter toClient = res.getWriter();
toClient.println("<html>");
toClient.println("<title>REGISTRO REALIZADO</title>");
toClient.println("Usuario "+user+" registrado con exito");
toClient.println("</html>");
toClient.close();
}
}
And this my web.xml:
I don't know what to do, thanks in advance.
Im getting an error i dont know why. I have this project:
And when i execute registro.html it works nicely:
But when i submit the post in the code i think it doesnt reach Registro.java
the code in registro.html is:
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Registro</title>
</head>
<body>
<form action="http://localhost:8080/Ejer2/Registro.java" method="POST">
<input type=hidden name=registro value=resultadoRegistro>
<BR><BR>Username: <input type=text name=user>
<BR><BR>Password: <input type=password name=pass>
<BR><BR><input type=submit value="Enviar"><input type=reset>
</form>
</body>
</html>
and in Registro.java this one:
package Ejer2;
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;
import javax.servlet.http.HttpSession;
import javax.servlet.*;
#SuppressWarnings("deprecation")
public class Registro extends HttpServlet implements SingleThreadModel{
private static final long serialVersionUID = 1L;
public Registro() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
HttpSession session=req.getSession(true);
Usuario miuser=(Usuario)session.getValue(session.getId());
if(miuser==null){
miuser=new Usuario(req.getParameter("user"),req.getParameter("password"));
session.putValue(session.getId(),miuser);
}
res.setContentType("text/html");
String user=req.getParameter("user");
//String pass = req.getParameter("pass");
PrintWriter toClient = res.getWriter();
toClient.println("<html>");
toClient.println("<title>REGISTRO REALIZADO</title>");
toClient.println("Usuario "+user+" registrado con exito");
toClient.println("</html>");
toClient.close();
}
}
What is the problem?
You can't use or call like Registro.java directly inside the html action rather you need to map the url pattern for your Registro servlet class as shown below:
#WebServlet(urlPatterns="/Registro")
public class Registro extends HttpServlet implements SingleThreadModel{
//Add your code here
}
Now use the above configured urlPattern as the action in your registro.html, shown below:
<form action="/Registro" method="POST">
Also, the other important point is that you don't need SingleThreadModel for the servlet classes in general (because all the requests will be served using the same servlet instance), but if you are using SingleThreadModel on purpose you can leave it as is.
I am very very new to this. and yeah it's a homework.
I am trying to make an HTML page with a form to send some variables to a servlet and the servlet sends an applete to the same form page. so far i succeeded in sending the applet alone. I tried using jQuery, but i couldn't send the HTML tags. I can only send text.
My code so far:
index.html
<html>
<head>
<title> title </title>
</head>
<body>
<form action = "Servlet">
<input type="text" name="Name" value="" size="5" />
<input type="submit" value="Submit" name="Submit" />
</form>
</body>
Servlet.java
package ServletPackage;
import java.awt.Font;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class Servlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public Servlet() {
super();
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html");
String nm;
nm = request.getParameter ("Name");
PrintWriter mess = response.getWriter();
mess.println("<html>");
mess.println("<head>");
mess.println("</head>");
mess.println("<body>");
mess.println("<b> You've entered Name: </b>" + nm);
mess.println("<p align=center>");
mess.println("<applet code='NameInShape.class' width=200 height=200>");
mess.println("<param name='NAME' value='" + nm + "'>");
mess.println(" </applet>");
mess.println("</p>");
mess.println("</html>");
mess.println("</body>");
mess.close();
}
public static void main( String[] args )
{ }
/**
* #see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
All help appreciated
One way to do it is by using RequestDispatcher to call a .jsp (JavaServer Pages) clone of your index.html with the parameters posted by your form. And don't worry, it's pretty simple to implement. The result will look like the initial page the form still available, but the applet will be called using the specified parameters.
You need to import RequestDispatcher (import javax.servlet.RequestDispatcher;) and then you can do something like this in your doPost method:
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
RequestDispatcher rd = request.getRequestDispatcher("clone.jsp");
rd.forward(request, response);
}
The method rd.forward(request, response); makes the parameters posted to your servlet available on the clone.jsp page, and you can insert them using <%=request.getParameter("ParameterName")%> inside the .jsp page.
For example, after adding the above code in your servlet, you could insert something like this in the clone.jsp page to embed the applet with a parameter received from the index.html form submission:
<applet code=Applet.class width=300 height=300>
<param name=NAME value="<%=request.getParameter("NAME")%>">
</applet>
i have a simple jsp page with one anchor tag which will call the servlet page:
The following is the jsp code
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Download Data</title>
</head>
<body>
View data in following format:<br>
MS-Excel
</body>
</html>
This is my servlet page :
package com.primeki.devlopment.usm.view;
import java.io.IOException;
import java.io.PrintWriter;
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("/ExcelServlet")
public class Filedownload extends HttpServlet {
private static final long serialVersionUID = 1L;
public Filedownload() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("application/vnd.ms-excel");
PrintWriter out = response.getWriter();
out.println("Name\tJob\tSalary");
out.println("Raj\tAccountant\t20000");
out.println("Vinay\tAccountant\t20000");
out.println("Rajesh\tAccountant\t20000");
out.println("\tTotal:\t=sum(c2:c3)");
out.close();
}
}
I am getting an error when i am clicking the anchor tag ...
i want to make an excel sheet to get download by click on the anchor tag .. but i am getting an error ... plz help in this....
I may be mistaken because I am new in Java EE but it seems that MS-Excel anchor is redirecting to Filedownload while your servlet is #WebServlet("/ExcelServlet").
Try changing your anchor to MS-Excel
You have named your WebServlet "/ExcelServlet" which means that it weill respond on requests made to http://{server}/{app-name}/ExcelServlet and you have a link with href = "Filedownload"
I have some code. It works in JSp but not in Java servlet. I am pasting my code here. Can u plz state the mistake in servlet file?
JSP:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%
String rollno=null;
String category=null;
rollno=request.getParameter("rollno");
category=request.getParameter("category");
out.println(rollno+"\n"+category+"\n");
%>
</body>
</html>
Java Servlet :-
import java.io.IOException;
import java.io.PrintWriter;
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 a extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
PrintWriter out=response.getWriter();
String rollno=null;
String category=null;
rollno=request.getParameter("rollno");
category=request.getParameter("category");
out.println(rollno+"\n"+category+"\n");
}
}
Use doGet method not doPost
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}