WHAT IS CORE JAVA AND ADVANCED JAVA?

Java Online Training

Firstly, there is no such concept like core java and advanced java. It is mainly created by the coaching centers to make their terminology easier. Java mainly consists of three parts j2se, j2ee &j2me.

1)      J2SE (Java2 Standard Edition)

2)      J2EE (Java2 Enterprise Edition)

3)      J2ME (Java2 Micro/Mobile Edition)

Here j2se deals with the fundamental parts of the java like oops concepts and their implementation in the language, which is termed as core java and whereas the rest of the two parts are considered as advanced java.

Core java is standalone java application, whereas advanced java deals with server side applications.

Without proper knowledge of core java, no one can jump on to learn advanced java.

 Java online training – Java J2EE

 

Java online training - Java J2EE

The Java Platform, Enterprise Edition or Java EE (formerly known as Java 2 Platform, Enterprise Edition or J2EE) has undergone several changes since Java J2EE-1.0 as well as numerous additions of new specifications.

Java J2EE 1.4, the predecessor to the Java EE 5 platform, has many powerful features than older version of Java api. Here are a few of the significant changes of Java J2EE:

In Java EE 5 platform most boilerplate requirements have been eliminated, and JavaScript XML descriptors are now optional. For example, the ejb-jar.xml Java script descriptor is no longer necessary in most cases.

Java EE 5 platform, more defaults are available, with a special emphasis on making them meaningful. Java Developers now have fewer details to remember.

The EJB software programming model is significantly simpler in Java EE 5 platform.

The new Java Persistence API is available to all Java api platform applications, including those based on Java EJB technology.

 What is J2EE?

Java 2 Enterprise Edition (J2EE) is a platform-independent, Java-based environment. It is developed by Sun Microsystem. It is mainly used for developing and deploying web-based applications.J2EE consists of APIs, set of services and protocols.

 Why J2EE?

  1. J2EE supports HTML, Java applets. It depends on Java Server Pages (JSP) and Servlet code to create HTML or other formatted data for the client.

The frameworks and technologies used in Java and J2EE share many of the same concepts (e.g. streams, containers, readers, writers, etc.).

  1. An EJB (Enterprise Java Bean) server offers functions such as threading, concurrency, security and memory management. These services are transparent to the author.
  2. JDBC is the standard interface for java databases.
  3. The Java servlet API boosts reliability for developers without requiring a graphical user interface.

 Why online training on J2EE?

 

Why online training on J2EE

J2EE is a very important environment in this era of IT. Being a Java-based environment, it is considered as a secure environment. So, there is a demand for J2EE developer in many organizations. Potential J2EE developers have a very good career in this field, especially if they have any global certification (from Sun) on that particular domain. But to clear the global examination is not as easy as you are thinking. So, you need a through training on it. But we all are very busy with our work load. So, all students are looking for flexible timings for their classes.

Overview of Servlet (Advanced Java)

 

Overview of Servlet (2)

What is Servlet?

Java Servlets are small programs that run on Application server and act as a middle layer between the requests coming from a Web browser (or other HTTP client) and databases (or applications on the HTTP server).

Java Servlets often serve the same resolution as programs implemented using the Common Gateway Interface (CGI).

 

Servlet Life Cycle

 

Servlet Life Cycle

Servlet life cycle means the entire process from its creation to its destruction.

  1. Servlet is initialized by calling init() methods.
  2. After that it calls its service() method to process the request.
  3. It is terminated by calling destroy() method.
  4. Finally it is collected by the garbage collector (GC) of the JVM (Java Virtual machine).

init() Method

The init() method is called when servlet is created first. init() is called for only once. It does the initializations. Example:

public void init() throws ServletException{

 // codes for initialization

}

service() Method

The service() method is responsible for processing the request. The servlet container calls this method. The service() method checks the HTTP request type (GET, POST, PUT, DELETE, etc.) and calls doGet, doPost, doPut, doDelete, etc. methods as appropriate. Example:

public void service(ServletRequest R, ServletResponse Re) throwsServletException, IOException{

            // Code here

}

doGet() Method

A GET request results from a normal request for a URL or from an HTML form that has no METHOD specified and it should be handled by doGet() method.

doPost() Method

A POST request results from an HTML form that specifically lists POST as the METHOD and it should be handled by doPost() method.

destroy() method

This is called for only once at the end of servlet’s life cycle. In that time all the databases need to be closed, halt background thread and need to do some cleanup tasks. Example:

public void destroy(){

// codes for Finalization

}

We offer Java online training to the learners throughout the globe. If you wish to learn more on it, you can join our Java training. Our Java online training is very interactive. All our Java trainers are highly qualified and experienced. They are the main strength of our Java online training. For more details on Java training contact us at+1-610-686-8077.

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