| Share this post! | Vote this! |
|
|
|
Basic skills that you must have to be a good web developer
Playing Sound on a webpage using Javascript and Flash Player
| Share this post! | Vote this! |
|
There are several ways to play sound in a web page. Why you need
sound in a web page. The most common type of feedback is sound. The
computer clicks when you select things, beeps when there are errors, and
makes other noises to alert you to situations. But Web pages don’t
usually have this type of feedback.
As I said above that there are several ways to play sound in web page. But the most common problem is the “Browser specific solutions”. Some will run on Internet explorer, while others will run on Mozilla Firefox and some on Google Chrome. more...
As I said above that there are several ways to play sound in web page. But the most common problem is the “Browser specific solutions”. Some will run on Internet explorer, while others will run on Mozilla Firefox and some on Google Chrome. more...
How Google Image Search Technology Works
| Share this post! | Vote this! |
|
Following Google’s launch of its image search, questions have been asked
about how the technology works and whether or not it is accurate. At
first glance, the search results appear to be fairly accurate and
intriguing. For those who are interested, the following video
presentation by Peter Linsley (originally delivered at SMX West in
February, 2009) will attempt to answer some of your questions on how
exactly Google images work and to some extent what it can be used for. more...Counting Active Users using JSP
| Share this post! | Vote this! |
|
Ever wondered how many users are viewing your web site at this moment?
well this article seems to answer that. We will learn how to count
active users using one session listener class and a JSP page. Once you
have read this article, you'll be able to see the number of active
sessions on your web site. This is all fun, so keep reading.
What is a Session ?
A session is a sort of temporary unique connection between the server and client ( browser ) by which the server keeps track of that specific user. That unique session can be used by web applications to display this content to one user and that content to the other user. more...
What is a Session ?
A session is a sort of temporary unique connection between the server and client ( browser ) by which the server keeps track of that specific user. That unique session can be used by web applications to display this content to one user and that content to the other user. more...
PHP Fetching URL Content With load() Function
| Share this post! | Vote this! |
|
PHP make this very easy by including functions like
file_get_contents() that has URL support. This code will get you the
contents of an URL.
PHP provide two method to fetch an URL - Curl and Fsockopen. But to use this we have to write a lot more code.
$contents = file_get_contents('http://example.com/rss.xml');PHP provide two method to fetch an URL - Curl and Fsockopen. But to use this we have to write a lot more code.
load()
So I decided to create my own function that makes it much more easier. more...Tomcat 6 : Web Application Configuration
| Share this post! | Vote this! |
|
Web applications consist of static content (HTML, images) as well as
dynamic content (Servlets, JSP's and Java Classes), normally a system
administrator although does not program them, will normally deploy them,
so a basic understanding on how Web applications work will help.
Web applications configuration can be broken down into two area's
Web applications are normally installed under the webapps directory in Tomcats home directory, the basic structure is in the diagram. more...
Web applications configuration can be broken down into two area's
- Understanding the structure and content of a Web application
- The deployment descriptor for a Web application (web.xml configuration file)
Web applications are normally installed under the webapps directory in Tomcats home directory, the basic structure is in the diagram. more...
Shared Tomcat Hosting
| Share this post! | Vote this! |
|
Many smaller companies run there entire system on a standalone server, running many Web Sites from one server is called virtual hosting. These hosting services allow for the sharing of resources such as a Web server, Database server, firewall, etc.
Virtual Hosting Concepts
Different Web site will have distinct Fully Qualified Domain Names (FQDN) which is served by a Web server. A FQDN is in two parts a host and a domain name (web1.datadisk.co.uk - host=web1 domainname = datadisk.co.uk), I have a brief introduction to domain names in my Exim section.
There are two ways that virtual hosting can be implemented
Virtual Hosting Concepts
Different Web site will have distinct Fully Qualified Domain Names (FQDN) which is served by a Web server. A FQDN is in two parts a host and a domain name (web1.datadisk.co.uk - host=web1 domainname = datadisk.co.uk), I have a brief introduction to domain names in my Exim section.
There are two ways that virtual hosting can be implemented
- IP-based virtual hosting - each web site domain needs to have a different IP address
- Name-based virtual hosting - web sites share an IP address and the web server determines which domain the request is for based on the HTTP request headers more...
Tomcat 6 Security
| Share this post! | Vote this! |
|
Most software downloaded can be checked that it has not been tampered
with or that you are downloading the correct version and not a hacked
version. Tomcat uses a MD5 digest to make sure that you have downloaded
the correct version, if one bit was to change in the software the MD5
digest will change. So when you have downloaded Tomcat, don't forget to
compare the MD5 digest with the official Tomcat website to check it's
integrity.
Securing Tomcat
When moving Tomcat into Production a number of actions must be performed to secure Tomcat, these are recommendations and you can choose to implement or not implement them. To start with I will discuss securing the Tomcat instance then discuss securing the Web application more...
Securing Tomcat
When moving Tomcat into Production a number of actions must be performed to secure Tomcat, these are recommendations and you can choose to implement or not implement them. To start with I will discuss securing the Tomcat instance then discuss securing the Web application more...
Tomcat 6 : Performance Testing
| Share this post! | Vote this! |
|
From a users point of view performance is the time it takes to click a
page to the time it is displayed (loaded into the browser), from an
administrator point of view there are two important properties that you
should measure for quantifying the performance of a web site
Before you start your web application design, you send set some goals on what you what to achieve more...
- Response Time
- Throughput
Before you start your web application design, you send set some goals on what you what to achieve more...
Tomcat : HTTP Connectors
| Share this post! | Vote this! |
|
Tomcat comes with a preconfigured HTTP connector that can handle
incoming HTTP requests from a browser, because of this Tomcat can act as
a standalone Web server, it can handle both HTTP and HTTPS requests.
Tomcat can be tied with both Apache and IIS, I will not be explaining
IIS so I point you to the Tomcat Apache web site.
The Java-based HTTP/1.1 Connector is the default connector configured in Tomcat, there are additional connectors that can make use of high performance IO features of the Java NIO library and a native version of the HTTP Connector written in C/C++ and coded to APR (Apache Portable Runtime). Both of the additional Connectors are new and hopefully will be come the standard connector.
HTTP Connectors
HTTP connectors are Java classes that implement the HTTP protocol, by default the Connector listens on port 8080 but this can be changed. There are a number of HTTP Connectors available more...
The Java-based HTTP/1.1 Connector is the default connector configured in Tomcat, there are additional connectors that can make use of high performance IO features of the Java NIO library and a native version of the HTTP Connector written in C/C++ and coded to APR (Apache Portable Runtime). Both of the additional Connectors are new and hopefully will be come the standard connector.
HTTP Connectors
HTTP connectors are Java classes that implement the HTTP protocol, by default the Connector listens on port 8080 but this can be changed. There are a number of HTTP Connectors available more...
Class Loaders in Tomcat
| Share this post! | Vote this! |
|
Each time a class is instantiated as an object or referenced
statically, that class must be loaded by the Java Virtual Machine (JVM)
into memory, Tomcat uses class loaders and has different behavior to
other class loaders. Tomcat allocates a class loader to each web
application, but there are global ones as well.
Class loader Overview
The class loader deals with loading classes that many be on a file system, embedded computer systems (ROM chip), across a network. The role of a class loader is to abstract the process of loading classes, making completely independent of any type of underlying data store.
Since J2SE 1.2 the JVM uses three different class loaders
Class loader Overview
The class loader deals with loading classes that many be on a file system, embedded computer systems (ROM chip), across a network. The role of a class loader is to abstract the process of loading classes, making completely independent of any type of underlying data store.
Since J2SE 1.2 the JVM uses three different class loaders
- Bootstrap class loader (also called the primordal class loader)
- Extension class loader
- System class loader more...
Tomcat Architecture
| Share this post! | Vote this! |
|
Tomcat is a container that is made up of pluggable components that fit
together in a nested manner. Tomcat is configurable you can set such
settings to use specialized filters, change port numbers and IP address
bindings, security settings, etc. You should always change the default
setting when using in a production environment especially the security
aspects, I will touch on this in the Tomcat security section. At first
Tomcat configuration files appear cryptic and difficult to understand,
but in future articles I will try to unpick the complexity of Tomcat into a easy understandable format. more...
Advanced Tomcat Features
| Share this post! | Vote this! |
|
The following subjects are discussed in this article
- Access Logs
- Single Sign-on
- Request Filtering
- Persistent Session Manager
- Tomcat and JDBC, JNDI
- JavaMail Session
- Configuring lifecycle listeners more...
Tomcat/Apache 6 : Ultimate Guide
| Share this post! | Vote this! |
|
Apache Tomcat
| Introduction | |
| Tomcat History | |
| Java EE | |
| Tomcat and Web Servers |
Web Applications
| Web Application History | |
| Server Side Java Servlets | |
| JavaServer Pages (JSP) | |
| MVC Architecture | |
| Summary |
Tomcat Installation
| Installing the JVM and Tomcat | |
| Tomcat Directory Tree | |
| Installing APR | |
| Troubleshooting Tips |
Tomcat Architecture
| Tomcat Directory Overview | |
| Tomcat Architecture | |
| Connect Architecture | |
| Lifecycle | |
| Configuration |
Basic Configuration
| Configuration Essentials | |
| Basic Server Configuration | |
| Web Based GUI configurator |
Advanced Features
| Valves | |
| Log Files | |
| Single Sign-on Implementation | |
| Restricting access via a Request Filter | |
| Persistent Sessions | |
| JNDI Resource Configuration | |
| Configuration Lifecycle Listeners |
Web Application Configuration
| Understanding the contents of a Web Application | |
| Understanding the Deployment Descriptor |
Web Application Administration
| Tomcat Manager Application | |
| Tomcat Manager - Web Interface | |
| Tomcat Manager - Managing Application with Ant | |
| Tomcat Manager - Using HTTP Requests | |
| Possible Problems | |
| Security Considerations |
Class Loaders
| Class Loader Overview | |
| Class Loader Behavior | |
| Security and Class Loaders | |
| Tomcat and Class Loaders | |
| Dynamic Class Reloading | |
| Common Class Loader Pitfalls |
HTTP Connectors
| HTTP Connectors | |
| Configuring Tomcat for SSL Support | |
| The Advanced NIO Connector | |
| The Native APR Connector | |
| CGI and SSI support | |
| Running Tomcat behind a Proxy Server | |
| Performance Tuning |
Tomcat and Apache HTTP Server
| AJP Connector Architecture | |
| Understanding Tomcat Workers | |
| Configuring SSL for Apache Web Server | |
| Tomcat Load Balancing with Apache |
JDBC Connectivity
| JDBC Basics | |
| Tomcat and JDBC | |
| JNDI Emulation and Pooling in Tomcat | |
| Complete example using Oracle |
Tomcat Security
Shared Tomcat Hosting
| Virtual Hosting Concepts | |
| Virtual Hosting in Apache | |
| Virtual Hosting in Tomcat | |
| Other Virtual Hosting Material (Tuning, Security) |
Monitoring and Managing Tomcat with JMX
| Introduction to JMX | |
| Instrumentation Level | |
| Agent Level (MBean Server, Connectors and protocols adapters, agent services) | |
| Distributed Services Level | |
| Anthology of MBeans | |
| JMX Manageable Elements | |
| Accessing JMX via Manager Proxy | |
| Accessing JMX via JConsole |
Clustering
Logging
| log4j | |
| JULI | |
| Log file Analysis |
Performance Testing
| Performance Concepts | |
| JMeter |
Performance Tuning
| Performance Tuning Best Practices | |
| Tomcat Error Messages | |
| JVM Tuning | |
| Tomcat Tuning |
Links
| The official Apache/Tomcat web site |
more...
Tomcat for beginning Web developers
| Share this post! | Vote this! |
|
About this tutorial
This tutorial gives Java Web developers an introduction to programming JavaServer Pages (JSPs), servlets, and Web services using Tomcat, an open source application server from the Apache Foundation. The tutorial guides you through the following tasks:
The tutorial covers the following:
This tutorial gives Java Web developers an introduction to programming JavaServer Pages (JSPs), servlets, and Web services using Tomcat, an open source application server from the Apache Foundation. The tutorial guides you through the following tasks:
- Downloading and installing your own Tomcat server.
- Coding and deploying a JSP on Tomcat.
- Coding and deploying a servlet on Tomcat.
- Coding and deploying a Web service using Tomcat and Apache Axis.
The tutorial covers the following:
- What is Tomcat?
- Tomcat installation and setup
- Your first JSP application on Tomcat
- Breaking into servlets development with Tomcat
- Discovering Web services development with Tomcat
- Summary
- Download
- Resources
Web App with jQuery, CoffeeScript, Ajax, Web.py & Heroku
| Share this post! | Vote this! |
|
The intent of this example is to utilize high-level tools to create a
very simple web app. The app will live on a single page that the Web.py
server will hand you when you go to the URL. Every two seconds, this
page will create a JSON object consisting of data from a text field on
the page, and a randomly-generated number. The JSON object will be sent
to the server as a POST request, and the server will respond by
modifying the data and returning it to the page as a new JSON object.
The page will take the data and update itself. Thus it makes the web
page a reasonably-complete user interface for the application (this app
will even automatically start up the web page, so it could be used as a
desktop application).
The web page is very minimal, with a text field for input and an H1 field to be manipulated by jQuery to display the output. The page lives in the templates subdirectory and is named displaydata.html which you'll shortly see is important: more...
The web page is very minimal, with a text field for input and an H1 field to be manipulated by jQuery to display the output. The page lives in the templates subdirectory and is named displaydata.html which you'll shortly see is important: more...
Using Java's Net::URL Class To Access URLs
| Share this post! | Vote this! |
|
Java's networking classes enable you to implement applications that
communicate across a network/remote connection, but the platform also
extends into the realm of the Internet and URLs. Java's URL class makes
accessing Web resources as easy as accessing a local file. Let's take a
look at how you can tap into the power of the URL class and read and
write data over URL connections.
http://www.go4expert.com:1234/mywebapps/JavaApp
The protocol element is identified as http. The host name is www.go4expert.com. The port number is 1234. The rest of the URL, /mywebapps/JavaApp, identifies the resource to be accessed on the site. The resource, in this case, happens to be a Web application. URLs can also include other elements, such as fragments and query strings. more...
Working With URLs
A URL identifies resources such as files, Web pages, and Web applications that exist on the Web. It consists of a number of syntactic elements. For example, note the following URL:http://www.go4expert.com:1234/mywebapps/JavaApp
The protocol element is identified as http. The host name is www.go4expert.com. The port number is 1234. The rest of the URL, /mywebapps/JavaApp, identifies the resource to be accessed on the site. The resource, in this case, happens to be a Web application. URLs can also include other elements, such as fragments and query strings. more...
Factors That Determine Whether Your Business Really Needs A Mobile App
| Share this post! | Vote this! |
|
Mobile consumers present a huge and
growing market that businesses can target to promote their products and
services. But for this to happen, they need to go mobile with their
business; and one of the better ways of going mobile is to build a
mobile app. Quite a number of businesses are already doing that and some
of them are experiencing continuing benefits of releasing a mobile app.
But, the keyword here is ‘some’ businesses and not all. This is because
not all businesses are optimizing the use of their apps and they got
themselves an app before considering certain essential factors.
Let’s take a look at these factors that determine whether a business’s idea of getting a mobile app has any merit. more...
10 Effective Steps To A Quick Website Audit
| Share this post! | Vote this! |
|
It’s no secret that in order to have a successful SEO campaign, you
first have to have a solid website that is optimized and built
correctly. Even if you have a great link building strategy, a sub-par
site won’t help you achieve much success. The first step in improving an
already existing site for SEO is to first conduct a site audit, or in
other words, find out what’s wrong and what components it might be
missing. Here are 10 quick steps that you can follow for a brief site
audit that will give you a basic overview of how well a site is doing in
terms of SEO. Keep in mind that this list isn’t the end-all check lists
of site audits, but it can help you get a great head-start on a site
makeover. more...
Analyzing the Importance and Necessity of Dedicated Web Hosting Services
| Share this post! | Vote this! |
|
Launching a website is a very important
aspect for every business. However, in case you are scouting the steps
to accomplish this, you need to understand that the very first step is
choosing a great hosting service. There are quite a few options for you
in this regards. All the information you collect will point out that, of
all the plans in the market, a dedicated server hosting will give you
the maximum ownership on your server.
Yet, the most important considerable
question is whether your business needs a completely dedicated hosting
service or you might scout other less complicated options? Here is an
analysis that might help you understand your stand on this issue. more...
