If you are a beginner when it comes to the Java programming language or even if you are an experienced programmer looking for some new tips&tricks, the best thing to do, and which has the advantage of being absolutely free of charge, is to search the Internet for Java tips and Java tutorials.

Try this instead of buying one or two books, and you are going to be impressed by the quantity of information you’ll find available about the domain. This is the easiest way to access tons of Java tutorials or a lot of very useful Java tips with no effort and no cost at all.

The Java programming language and platform were first developed during the early nineties and a few years later it was re-designed for use in the Internet, and since then its popularity greatly increased, especially on the server side of the Internet.

Nowadays there are quite a lot of Java experts and a lot of documentation on this subject has been written, so if you are a beginner start searching for Java tutorials to learn more, and if you are an advanced user, you can always make use of the large number of Java tips that can be found and that can help you solve almost every problem you encounter in your path to making perfect Java programs.

Even for those who are ablsolute beginners in learning about Java, better and easier than attending courses is learning from the Internet Java tutorials. They can find anything from getting started, the basics of the Java language, essential classes, to more specialized tutorials like security in Java, graphics, working with databases and many more things. You can find websites that are specialized in giving Java tips and Java tutorials to those who need. Those tutorials and tips are written by experts and are placed in categories, which helps you immediately find the Java tips or the Java tutorials that you are looking for. The best thing when learning is to read more Java tutorials, and to combine the Java tutorials you learn from with the short and useful Java tips you find.

On the other side, if you are an experienced programmer and you want to share your knowledge, you can begin writing Java tutorials and Java tips to help the newbies and other who need it.

When writing Java tutorials make sure you make yourself clear and understood and that you are covering all the aspects of the problem.
Also, when writing Java tips, if you want people to easily find and understand the information you are delivering there are some ‘rules’ you should respect, like choosing the best title of the Java tip, that captures exactly what you are presenting, and the best subtitle of course, which must expand the title a little, you can also add a short summary or comment if you wish where you describe what your Java tips do, then proceed with the introduction, the code listing, the explanations for it and also a little conclusion if you desire. You can even include a link to more detailed Java tutorials on that subject also.

Java is an object oriented and structured programming language, designed by Sun Microsystems in the year 1991. Java is a third generation programming language. It has an in built application interface which has the ability to handle the graphics and user interfaces that creates the applets or applications.

The very advantage of java is its “portability”, the programmer can write the program and compile in the same kind of environment as it is written and after that it can be run anywhere.

Java relates to both C and C++, it uses the syntax of C and the object oriented concepts from c++ and this makes Java appealing. When a source code is given as the input, the output from java compiler is the “bytecode”. Bytecode contains set of instructions which will be executed by Java Virtual machine (JVM). In a more simple way, I can say JVM interprets the bytecode and this is the reason that java can be run anywhere. Applets are the programs which are embedded in to web page and can be executed where as the applications are directly executed by JVM.

It is not always possible to compile the complete program at the same time, so java uses just-in-time compiler to compile a set of bytecodes in real time for execution and the remaining codes will just be interpreted and thus makes the execution of Java program faster. The two main building blocks of java programming are the classes and objects. Objects are the instance of class and class is a template for creating objects.

Unlike in c/c++ you need not manually allocate/de allocate dynamic memory, java itself does this and also it has garbage collection for the unused objects. Java program handles the run time errors too. Java supports multithreaded programming.

Decouple validation processes from your business object implementations

Version 1.3 of the Java platform saw the introduction of the dynamic proxy facility. Dynamic proxies offer many interesting solutions to Java developers, including a validation scheme that easily decouples validation logic from an application’s core business logic. In this article, Java developer Eric Olson shows you how dynamic proxies can keep your core application code free of validation routines and focused solely on business logic.

Validation is an essential aspect of many enterprise applications. Most business methods contain validation logic to ensure that pre-conditions are met before carrying out business logic. Code that deals with values entered through a user interface employs validation logic to ensure that the values entered by a user are valid before carrying out actions that may affect other areas of the application or other users. Validation is an especially important component of applications that employ and interact with other loosely coupled components, as well as services that may not be strict in their assertions.

As important as it is to the safety and functionality of your business applications, core application logic is often cluttered with validation routines. Validation processes are often scattered throughout method calls, making it difficult to tell the difference between validation logic and core business logic. In most cases, business objects and methods must know some details of the validation process and deal with them directly in their implementation — for example, a business object may throw a validation exception directly from the business method (either coded directly in the method, or as a result of calling some validation service). The validation exception in this case is really a byproduct of the validation process, however, and would ideally be hidden from the business object implementation.

In this article, I’ll show you a more decoupled and centralized approach to validation, using the dynamic proxy facility introduced to the Java platform with version 1.3. Working with a single example throughout the article, I’ll demonstrate the weaknesses of both tightly coupled and loosely coupled validation schemes, and then show you how dynamic

What is java? For the sake of record here is a small introduction.

A high-level programming language developed by Sun Microsystems. Java was originally called OAK, and was designed for handheld devices and set-top boxes. Oak was unsuccessful so in 1995 Sun changed the name to Java and modified the language to take advantage of the burgeoning World Wide Web.

Java is an object-oriented language similar to C++, but simplified to eliminate language features that cause common programming errors. Java source code files (files with a .java extension) are compiled into a format called bytecode (files with a .class extension), which can then be executed by a Java interpreter. Compiled Java code can run on most computers because Java interpreters and runtime environments, known as Java Virtual Machines (VMs), exist for most operating systems, including UNIX, the Macintosh OS, and Windows. Bytecode can also be converted directly into machine language instructions by a just-in-time compiler (JIT).

Java is a general purpose programming language with a number of features that make the language well suited for use on the World Wide Web. Small Java applications are called Java applets and can be downloaded from a Web server and run on your computer by a Java-compatible Web browser, such as Netscape Navigator or Microsoft Internet Explorer.