This post is a step-by-step guide to build an application using GWT-RPC . Just to make it more realistic , I have used a back-end database to store the records. I have used MySql as a database and Tomcat 6.0 as a deployment web server. If you are interested to have a look at the code and then the post , it can be downloaded from here. Let me start with a small but specific description of GWT-RPC.

GWT provides a text-type label by default. You can set a text to a label but it is not possible to set a HTML to a Gwt label unless you do few changes.

Label myLabel = new Label();
myLabel.setText("This is my label");
myLabel.setHtml("This<br>is<br>my<br>label"); // compilation error

To achieve this , you can create your own customized label which [...]

A Path Traversal attack targets the files and directories which are saved outside the root folder. An attacker aims for a files path stored in the web server. An attacker use the combination of dot-dot-slash(../) to browse to arbitrary directories and files. The dot-dot-slash sequence helps an attacker to move up in any directory location. The attacker not only can access any arbitrary files/directories from your web server , it is possible to upload some malicious files to some location in your web server , if the proper care is not taken.

A web server takes a request from the client and send the response back to the client. A servlet is a web application component that can talk to web server through the container it’s deployed into. We know , we need to do servlet mapping into web.xml to define the url pattern to access the [...]

I am writing this post on the basis of my learning on refreshing UI(User interface) without restarting server(Tomcat , in my case) on update of an XML which resides inside the container. Often we follow the design where we write our application configuration into an XML file and read – write the XML based on the requirements.

Window.open() method opens a new window . If we try to refresh the parent on change of something in the opened window , what are the ways to do it ? One possible way is to call reload(true) on the opener. It reloads the whole document for you.

When we send a request to the server , we expect a response. When we make an Ajax call to server with the help of XMLHttpRequest ,we have an option to get the response in many different formats. It can be a plain text , CSV(comma separated) , Xml etc. If the return data is in complex form or in a form of an object you need something called JSON. This post would give you a start up confidence to use JSON.

Ajax is nothing but getting the XMLHttpRequest and work on it to get or post data. Forming an XMLHttpRequest varies form browser to browser. This post shows , how to construct XMLHttpRequest object seamlessly.