The following table summarizes the differences between method overriding and method overloading:

Method Overriding	Method Overloading
Arguments of overridden methods cannot be changed.	Arguments of overloaded methods can be changed.
Method return types cannot be changed except covariant return types.	Return types can be changed.
Exceptions must not throw new or broader checked exceptions.	Exceptions can be changed.
It happens at runtime.	It happens at compile-time.
An object type determines which method is selected.	A reference type determines which method is selected.

Exceptions	Assertions
An exception tells the user of the program that something in the program went wrong.	An assertion documents a program. When it fails, it informs that the program has a bug.
Exceptions are created to deal with problems that might occur in the program.	Assertions are written to state the concepts of a program.
Exceptions are used to test input/output as well as whether parameters are legal or not.	Assertions are documentations that can be checked by running the program.

According to method overriding, an overriding method must follow the following rules:

• It must have the same argument list.
• It must have the same return type, new to Java 5. The return type can be a subclass – this is known as covariant return.
• It must not have a more restrictive access modifier.
• It may have a less restrictive access modifier.
• It must not throw new or broader checked exceptions.
• It may throw fewer or narrower checked exceptions, or any unchecked exception.

JavaBean is a reusable software component that can be visually manipulated using the builder tool. The following are the JavaBean Listener naming rules:

• Listener method names that are used to register a listener with an event source must use the prefix add followed by the listener type.
• Listener method names that are used to remove a listener must use the prefix remove followed by the listener type.
• The type of listener to be added or removed must be passed as the argument to the method.
• Listener method names must end with the word “Listener”.

A variable arity method allows the number of arguments in a method call to be varied. Invocations of this method may contain more actual parameters than formal parameters. The last parameter for the variable arity method is as follows:

The ellipses ( ) is specified between the type and the formal parameter name. Here, type can be a primitive type, or a reference type, or a type parameter. Such a parameter is called a varargs parameter. A variable arity method can be formed as a fixed arity method. For example:

public static void testMethod(int x, int args)

The varargs parameter in a variable arity method is always interpreted as having the type. It is heavily used in formatting text representation of values.

Now days Sun is providng its latest OpenOffice.org specialist certification exam that enables you to certify your desktop productivity skills in the OpenOffice.org 3 application.

Click the following link to get the latest information about certification contents and purchase:

http://www.sun.com/training/certification/openoffice/index.xml

This is the only Sun approved certification for OpenOffice.org. After gettting this certification the worldwide credential validates your knowledge of basic and advanced text processing functionality using OpenOffice.org.

This exam can be taken by you if you are:

1. An entry level Office user.
2. Migrating from other Office productivity suites
3. A moderately advanced Office productivity user.
4. An average Office productivity user.

Sun’s CX310-065 test is the latest exam for the Sun Certified Java Programmer certification on the Java 2 Platform 6.0. It validates your understanding of the basic syntax and structure of the Java programming language and proves that you can create Java technology applications that run on server and desktop systems using Java SE 6. It checks the exception handling, collections, assertions, threads, and flow control in greater depth. The older version test CX-310-055 is also available, which tests your knowledge on the Java 2 Platform 5.0. This is an entry-level test, which is a pre-requisite for various advanced level certifications such as the SCJD, SCBCD and SCWCD certifications. The following table depicts the comparison between SCJP 1.5 and SCJP 1.6:

To get a glimpse of the SCJP certification exam PrepKits, download its free demo version (which contains 15 free practice questions). Click the links below:

Sun Certified Java Programmer (SCJP 5.0)
or
Sun Certified Java Programmer (SCJP 6.0)
or
Sun Certified Java Programmer (SCJP 6.0) upgrade exam

SCJP stands for Sun Certified Java Programmer’s certification exam. It covers the standard edition 6 of java. It is career elivator tool for those programmers that are experienced using the Java programming language. After achieving this certification, it provides a clear vision to a programmer who understands the basic syntax and structure of the Java programming language and can create Java technology applications that run on server and desktop systems using Java SE 6.

SCJP exam is available in the following versions:

1. SCJP 1.5(CX310-055 and CX310-056)
2. SCJP 1.6(CX310-065 and CX310-66)

SCJP 1.5 and SCJP 1.6 are very different from the older versions of the exam.

SCJP 1.6 has added some new features, which are as follows:

1. NavigableSet interface
2. NavigableMap interface
3. Console class

The major changes that took place in the 1.5 version are as follows:

1. Autoboxing and Unboxing
2. Covariant returns
3. Enhanced for loop (for-each)
4. Enumeration (enum)
5. Generics
6. Static Imports
7. Variable-argument lists (VarArgs)
8. StringBuilder class

NavigableSet interface: The NavigableSet interface extends the SortedSet interface in which the elements are ordered either by natural ordering or using a Comparator. It contains methods to find out the closest matches for given search targets. The elements of the NavigableSet interface must be mutually comparable. The elements of the NavigableSet interface can be accessed and traversed in either ascending or descending order.

NavigableMap interface: The NavigableMap interface extends the SortedMap interface in which the elements are ordered either by natural ordering or by using a Comparator. It contains methods to find out the closest matches for given search targets. All keys inserted into a sorted map must implement the Comparable interface and must be mutually comparable. The elements of the NavigableSet interface can be accessed and traversed in either ascending or descending order.

Console Class: The Console class extends the Object class and has convenience methods to read from and write to the console objects. Also, the Console class has the readPassword() method to read a password from the console. If the underlying virtual machine has a console, it can be obtained by invoking the System.console() method. If no console device is available, then an invocation of the System.console() method returns null.

The SCJP test consists of multiple-choice questions. There are no case study type questions and the test is not adaptive. You will be required to attempt approximately 72 questions in 210 minutes. To pass, you need a score of 65%. Sun has specified more than thirty five objectives for Sun test CX310-065 (Sun Certified Programmer for the Java Platform, Standard Edition 6). These objectives are grouped under seven topics. Before taking the test, an individual should possess a good command over the following areas:

1. Nested and inner classes, interfaces, packages, import statements, enums, and abstract classes.
2. JavaBeans naming conventions in code. Using variable-length argument list in code.
3. Overloading, overriding
4. Default constructor
5. Assertion and differentiating between appropriate and inappropriate use of assertion.
6. Differentiate between Runtime exception, checked exception, and an error.
7. Wrapper classes and autobxing and unboxing
8. String, StringBuffer and StringBuider
9. Correct and incorrect overrides of hashcode and equals method. Differentiating between == and equals methods.
10. Generics with collection API, particularly with Set, List, and Map interfaces. Explaining the difference between generic and non-generic versions of collection API. Writing generic methods using wildcard types.
11. NavigableSet and NavigableMap interfaces.
12. Using Comparator and Comparable interfaces to manipulate an array by sorting, performing binary search and conversion of array to list.

The following are the benefits of <b> SCJP</b>:

1. SCJP certification proves your expertise on the Sun Java products and technologies.
2. Professionals holding the SCJP certification are preferred by the employers and they also get preference in promotions.
3. SCJP certification is helpful for professionals who want to upgrade their credentials and get recognition from the industry.
4. SCJP Certified professional can find appropriate jobs easily and get paid more.