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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.

0
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2answers
61 views

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 ...
2
votes
1answer
118 views

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 ...
2
votes
1answer
152 views

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. ...
3
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1answer
56 views
1
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1answer
465 views

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 ...
2
votes
1answer
3k views

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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2answers
95 views

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 ...
1
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1answer
451 views

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: ...
3
votes
3answers
84 views

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, ...
3
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0answers
39 views

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 ...
4
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1answer
86 views

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. ...
1
vote
0answers
2k views

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: ...
3
votes
2answers
101 views

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 ...
2
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2answers
243 views

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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0answers
104 views

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 ...
1
vote
0answers
83 views

Java Servlet GET/POST parameter error checking utility

I have written an imperfect utility for parameter verification and error checking of simple parameters passed to a Java Servlet via GET/POST requests. As a junior programmer, I got tired of having to ...
5
votes
2answers
866 views

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 ...
5
votes
1answer
2k views

Java login system using JSP and servlets

The system is pretty simple. Here is how the database looks: ...
4
votes
1answer
46 views

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. ...
5
votes
3answers
82 views

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 ...
6
votes
2answers
954 views

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: ...
6
votes
1answer
95 views

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 ...
1
vote
1answer
183 views

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 ...
8
votes
3answers
12k views

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 ...
4
votes
1answer
6k views

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 ...
3
votes
1answer
374 views

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 ...
3
votes
0answers
3k views

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 ...
2
votes
1answer
320 views

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 ...
4
votes
0answers
527 views

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 ...
6
votes
1answer
116 views

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 ...
1
vote
2answers
5k views

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 ...
4
votes
1answer
2k views

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: ...
5
votes
3answers
5k views

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: ...
1
vote
3answers
29k views

A Java Web App with Servlets, JSP and Session: shopping cart example

This is the only Servlet I have: ...
2
votes
1answer
156 views

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. ...
5
votes
3answers
9k views

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 / ...
6
votes
1answer
9k views

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 ...
3
votes
1answer
496 views

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 ...
10
votes
2answers
5k views

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 ...
8
votes
2answers
875 views

MVC controller code

Please review my servlet. ...
6
votes
2answers
9k views

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. ...
10
votes
2answers
786 views

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 ...
-1
votes
1answer
845 views

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 : ...
-2
votes
1answer
5k views

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 ...
2
votes
1answer
276 views

How can I tidy up this servlet parameter check code?

One of the servlet in my web app takes parameters in the form www.service.com/servletname/parameter1/parameter2. The first parameter is required and the second ...
2
votes
1answer
572 views

Am I using appropriate methods in this login system?

I have had to do a crash course in JSP, Servlets, and JDBC. I decided to attempt a Login System. I'm unsure if my use of try/catch is appropriate and if I am closing database connections correctly. ...
1
vote
2answers
3k views

Correct implementation for background task execution in web application?

I have a simple servlet which merely serves some cached data back to the user. I also have a background thread which runs at fixed intervals to refresh the cached data. Is this a reasonable ...
2
votes
1answer
1k views

Tomcat/JSP/servlets web-project

This is a simple sort of array. The array (in fact I used ArrayList) is stored in default_list.txt file on server, all changes ...
1
vote
2answers
310 views

Is there a more efficient way of loading views within my java app?

I'm building a web application in Java. I'm new to Java, so before I get too far into this... I'm hoping to take advantage of all the experience here and learn the problems with this setup. My ...
7
votes
2answers
374 views

Handling optional parameters in a servlet

I have a form that submits to a servlet that has optional parameters. If they are empty they are just ignored. This is the template I am using: ...