Latest Articles

Android Header and Footer layout example

29 September 2013

In this tutorial we will create an Android Header and Footer activity layout.

Components reuse is an essential concept when we design an application's User Interface. Android applications are no exception to this rule. In this tutorial we will create an Android activity compose... Read more

How to configure multiple Java web applications in New Relic

21 September 2013

In this tutorial we will see how to configure multiple Java web applications in New Relic

When we configure the New Relic agent to monitor our Java based application server it will by default aggregate all deployed web applications in a single application and show the corresponding aggrega... Read more

apm configuration java new-relic web

Java EE HTML5 WebSockets Encoder and Decoder example

10 September 2013

In this tutorial we will implement a Java EE ServerEndpoint message Encoder and Decoder in order to convert HTML5 websocket messages into Java objects (and also the reverse operation of converting Java objects into ready to be sent websocket messages).

As we have seen in previous examples a ServerEndpoint is the Java EE implementation of the server-side HTML5 websocket component: Java EE HTML5 WebSocket exampleJava EE HTML5 WebSockets with multiple ... Read more

html5 io java java-ee web websockets

JAAS logout example

31 August 2013

In this tutorial we will see how to logout users authenticated via JAAS.

Following the first couple of articles related with JAAS, some readers requested a new article about the JAAS logout process. This article will show how to logout users authenticated via JAAS and will... Read more

jaas java security tomcat web

Java EE HTML5 WebSockets with multiple clients example

22 August 2013

In this tutorial we will implement a message broadcast sample application using only HTML5 websockets. The server-side will be implemented with Java EE ServerEndpoint.

In the previous tutorial - Java EE HTML5 WebSocket example - we have implemented a simple Java EE WebSockets enabled application where the client sent a simple message to the server over a websocket a... Read more

html5 io java java-ee web websockets

Java EE HTML5 WebSocket example

12 August 2013

In this tutorial we will implement an HTML5 websocket resorting to the Java EE websocket implementation (ServerEndpoint).

The HTML5 specification brought the capability for web browsers to establish full-duplex TCP connections with websocket compliant servers.In other words, browsers are now able to establish a connectio... Read more

html5 io java java-ee web websockets

Android 'Application not Installed' java.lang.SecurityException [invalid digest for] or [Package ... has no certificates at entry]

07 August 2013

How to solve Android 'Application not Installed' caused by java.lang.SecurityException [invalid digest for] or [Package ... has no certificates at entry] when we sign an Android APK and install it in an Android device.

We sign an Android application (APK) using jarsigner signing tool. While installing the signed APK in an Android device we get the following exception in LogCat: Exception reading res/drawable/[some_... Read more

android java troubleshooting

EJB passivation and activation example

05 August 2013

In this tutorial we will cover Java EE Stateful Session Bean passivation and activation mechanism.

Stateful Session Beans are usually coupled with some given client and - as the name states - they keep state across client invocations.Since a conversation with a client may be long-lived, and many si... Read more

activation ejb java java-ee passivation stateful

About the author

Gonçalo Marques is a Software Engineer with several years of experience in software development and architecture definition. During this period his main focus was delivering software solutions in banking, telecommunications and governmental areas. He created the Bytes Lounge website with one ultimate goal: share his knowledge with the software development community. His main area of expertise is Java and open source.

GitHub profile: https://github.com/gonmarques

He is also the author of the WiFi File Browser Android application: