Questions tagged [servlets]
Servlet is a Java application programming interface (API) running on the server machine which can intercept on the requests made by the client and can generate/send a response accordingly.
56
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synchronized access to HttpSession attribute vs static ConcurrentMap with HttpSessionListener
As a part of library implementing websocket Guice scopes I need to maintain an object related to each HttpSession called ...
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1
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A Java EE7 web application for counting views in a static HTML page - follow-up
(See the initial and previous version.)
This time, I have incorporated all the good points made by mtj. See what I have:
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A Java EE7 web application for counting views in a static HTML page
I have this blog lurking around in the web. It's just static HTML, but I was interested to keep track of all the views on that blog. Finally, I end up with the following web application:
(The Java ...
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Correct synchronization of reads and writes to ConcurrentHashMap and ConcurrentLinkedQueue
I am writing a web application (Servlets, JDBC, no Spring - for learning purposes) that accepts orders from customers, while registered couriers can choose which one of these orders they want to ...
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any better way than using old servlet api for downloads
I am wondering if the following code can be modified to be used with latest version of spring APIs?
The following code works fine. However, I wanted to know if servlet APIs can be avoided which i have ...
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Servlet to let a user download a file
Is the code below an efficient way to get the zip file from the server? The code works fine but I'm wondering if I should throw some exceptions for the following conditions:
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3
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Java Servlet & JSP simple login
I am currently learning Java Servlets and JSP at university. As a little practice I created a project where I want to be able to login into a protected area. Now, I got it working by using a ...
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2
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681
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Servlet filter which detects if the authenticated user is a service account
My concern with this code is that I am forcing execution repeatedly through the same pathway for the sake of a readability that I'm not convinced by.
It's a servlet filter which detects if the ...
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167
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Implementation of login and registration functions in servlet filter
I'm a newbie in servlet API. I have a test task to create a very simple web app with one home page and an authorization form. The requirement is to use filter somewhere in my app.
Given that it's a ...
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Servlet doPost method that handles multiple actions
I'm interested in reducing the repetition in the doPost() method of my servlet. Specifically, I don't like the loop and error handling repetition.
Any other refactoring advice will also be helpful.
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Simple login with jsp
I made a simple login page with Java EE, jsp, servlet, tomcat and jdbc.
It does following:
login user
register user
after login it creates token for the session so ya can be directed from start page ...
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answer
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Server side validation for reCAPTCHA V2 or Invisible reCAPTCHA with Java (Servlet)
The main reason for this post is that I spent quite a lot of time searching the easiest way to validate recaptcha V2. So I'm going to share my knowledge to avoid further time wastage of developers.
I'...
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2
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Practicing Java servlets, MySQL and JSON - follow-up
(See the previous iteration.)
What's new
I have incorporated all the points of Dmytro Maslenko's answer. My code seems a little bit tidier.
Code
AddPersonController.java
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Practicing Java servlets, MySQL and JSON
(See the next iteration.)
Introduction
This is my attempt at a simplistic web application just for the sake of practice. I have three main servlets:
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3
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Shell script to rebuild a Java webapp
I am asking for an experienced person to review my basic shell script. I do not write them at work, but I am a software developer. I am using this for my personal project that I am working on. Later, ...
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0
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oEmbed provider servlet to handle four media types
I would like to add oEmbed tags to my site (I'm the oEmbed api provider). My api should respond the results based on the file type.
oEmbed Types has
Photo
Video
Link
Rich
My response to photo ...
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1
answer
95
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Authenticating and redirecting six specific users
In a project I have a few long switch statements which seem ugly to me. Please suggest how to refactor the following code.
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Create HTML table in a Java Servlet
Using a java servlet, I've been doing the same approach to building or updating HTML. I create the basic table on the HTML page, then call for the body from the servlet with ajax.
As an example:
...
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2
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132
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Filter request code handler
I use the following code which works OK, the code is filtering requests and in case there are too many requests it sends some logs/errors
since I'm very new to Java my question if there is a better ...
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2
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709
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Logging all API call traffic in Java servlets
We have a few servlets like the one below, taking JSON request and produce JSON response. And the requirement is to log all API call traffic.
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0
answers
301
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Sending JSON from a checkbox form
I coded this, which is working but I think there is a better way to do this.. I have a form where the user can check from checkboxes. For each checkbox I have multiple info that I want to send to my ...
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Thread Safe Servlet
I am working on a JSP MVC web application. I am confused about Thread-Safe Servlet concept. Following is my code, please tell me is it thread safe or not. Also, tell me the reason that why it is ...
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2k
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Java login system using JSP and servlets
The system is pretty simple. Here is how the database looks:
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1
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50
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Memory mapped classpath HttpServlet
I have a single page application where the resources sit on the classpath. Any request for a resource that doesn't exist should redirect to the index.html page. ...
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UrlRouter which uses regular expressions to find out what to do
I have created UrlRouter. It should call appropriate controllers methods with extracted values as a parameters. It works fine, but my boss told me that I should ...
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1k
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Servlet file uploader
I think this code looks ugly, especially with the multiple try-catch blocks, but I don't know how to rewrite it:
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1
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106
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Creating an in-memory ViewCounter that commits to database every 10 minutes
This singleton is responsible for counting every pageview (called Routes in our case) we get by id, until the timer runs out and commits the results to the database in one query. Then the counter gets ...
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1
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196
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Web application for recording blog comments
I am working on some coursework for a simple Java EE web application that records blog comments. On the add comment page there are two fields: name and ...
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3
answers
17k
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Sending a file in servlet response, using a class inside a method
I am processing file inside my method - basically preparing it for the download.
But I decided to split actions for setting headers and reading bytes.
As Java does not support method declaration ...
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4
votes
1
answer
11k
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Filter to block duplicate POST submission on server side
I am working on a JSF 1.1 webapp. Lots of POST request take some time and users have the bad habit of clicking again when it takes too long. I am planning to target all the long running processes and ...
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1
answer
395
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Servlet responses to upload/download requests
My task is to write a program to store files in object store. One of the subtasks requires to send json or xml format response to the file uploader/downloader as requested by client.
The following ...
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Authorization token from servlet filter stores user name
I'm having some difficulty with servlet and filter lifecycles. The intention here is to use the front controller pattern with a simple login; authentication is accomplished with the filter.
Am I ...
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Open source Pastebin tool made in JSP and servlet
I'm a student and still studying. I just made my own Pastebin tool to generate source code. I've also contributed this project as an open source. You could see this project from here.
If you wish to ...
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626
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Exception logger for servlets and JSPs
I hate using unnecessary catch blocks and I like to see my code look beautiful. In most of the cases in my project, which is a web application, I can't declare many ...
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Entering information about a business and finding matches
I'm writing a Java Servlet application where the users must enter information about a business. I'd like to prevent as many duplicate entries in the MySQL database as possible and I'd appreciate ...
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2
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Servlet and JSP for user registration, with CAPTCHA and error handling
I have a form that submits to a registration Servlet, which inserts a new user to the database when they sign up to the web application. Depending on the erroneous user input, the Servlet will ...
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1
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Error Handling in Servlets and JSPs
I have an HTML login form that is processed by a servlet, which then redirects the user to a result page.
login.jsp:
...
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3
answers
5k
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User registration Servlet
I have a servlet that processes user registration to a website. It takes inputs from an HTML form like username, password, email, etc.
MySQL Table:
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vote
3
answers
34k
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A Java Web App with Servlets, JSP and Session: shopping cart example
This is the only Servlet I have:
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Servlet WebClient: How do I best solve for multiple servlet requests?
This is working code presently visible here. Basically, this is still a work in process, but I do not want to go much further down the road without peer review. I've limited the source to the servlet. ...
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3
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Unit testing a servlet in a meaningful way
I have to write a unit test for the method processRequest in the servlet below and I'm wondering if:
It just shouldn't be done.
The class should be rewritten / ...
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votes
1
answer
11k
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Single Sign On - SAML Response generation
I am trying to implement a IDP initiated Single Sign On Solution (service similar to onelogin's) to Cloud based Service providers such as Google Apps, Salesforce etc.
The project is a Maven eclipse ...
- 225
3
votes
1
answer
530
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Mutualising multi-threaded calls to EJB from Servlet
I have a Servlet that makes an EJB call to a backing server which takes about a second to return some data that changes reasonably regularly.
I can't cache the data on the servlet-side, so I have ...
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2
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Simple servlet code to sum digits
This servlet takes an input from the user and
Stores the number inside the bean but with spaces in between each digit then stores the bean in the request scope.
If the last digit is even, sums the ...
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1k
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7
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2
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11k
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Implement HTTP Server with persistent connection
I am trying to implement a HTTP Server in Java, I want the server to use a persistent connection per thread for request and response. After some research on Google, this is how my program looks like. ...
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801
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Servlet for querying database on some high-loaded system
What should the code do: Process client HTML requests, query database and return the answer in XML. Working with a high load.
I need to know how can it be optimized.
Is something terribly wrong with ...
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Please check my example about jquery autocomple with servlet [closed]
Please check my code, did i get some things wrong
I'm a newbie in jquery and ajax, please check and show me how to fix this
In jsp page :
...
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1
answer
6k
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file downloading using jsp but not readable [closed]
I am trying to download files using jsp but then downloaded files are not readable.
Suppose if i download pdf files then it can not opened,if i download jpg files then it can not opened and similarily ...
