WonderFALL news & savings from uCertify!!!!

Fall into crisp, cool autumn savings with uCertify !

This offer is available for the first 100 customers only. Be one of the first to buy any of our PrepKits and get the ONLINE version absolutely FREE! Access the PrepKit from any computer, your iPhone or iPad! How COOL is that?!

Choose from over 300 test prep software for CompTIA, Microsoft, Oracle, IBM, Cisco, CCNA & many more. Nobody beats our breadth and depth of experience.

Buy our PrepKits and Save upto 50%! And yes, get the online and mobile versions absolutely FREE!

http://www.ucertify.me

Simply sign up or login with your existing account and add the Prepkit of your choice and and access it from anywhere. You can add your license information from this link

http://www.ucertify.me/myprofile.php?func=mylicense

iPhone and iPad users signup to http://learn.ucertify.com or login with your existing account and add the Prepkit of your choice and and access it from your iPhone and iPad. You can add your license information from this link

http://learn.ucertify.com/myprofile.php?func=mylicense

Click here now to Save : uCertify’s WonderFALL Sale!

Happy Shopping & Happy Learning!

Your uCertify Team

http://www.ucertify.com

Constructor overloading is a technique in Java in which a class can have any number of constructors that differ in parameter lists. A constructor uses its arguments to initialize the new object’s state. The compiler differentiates these constructors by taking into account the number of parameters in the list and their types.

As constructors are not members of a class, they are not inherited by subclasses. Therefore, each of the subclasses must specifically implement any constructors it needs. However, a subclass can use the constructors of its superclass by using the super keyword.

The lowerKey(k) method of the NavigableMap interface returns the greatest key in the map strictly less than k. It returns a null value if no such key is found. The lowerKey(k) method throws the ClassCastException if the specified key cannot be compared with the keys currently in the map. It throws the NullPointerException if the specified key is null and the map does not permit null keys

The lowerEntry(k) method of the NavigableMap interface returns a key value pair with the greatest key in the map strictly less than k. It returns a null value if no such key is found. The lowerEntry(k) method throws the ClassCastException if the specified key cannot be compared with the keys currently in the map. It throws the NullPointerException if the specified key is null and this map does not permit null keys

The descendingMap() method of the NavigableMap interface returns a navigable map according to the descending order of keys. This method returns a map that is similar to the result of the Collections.reverseOrder(comparator()) method. The expression m.descendingMap().descendingMap() returns a map exactly equal to map m.

The descendingKeySet() method of the NavigableMap interface returns a navigable set according to the descending order of keys in the map. The navigable set obtained as a result of the descendingKeySet() method supports element removal via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. However, it does not support the add and addAll operations

The File class is an abstract class used for file operations such as creating empty files, deleting files, searching for a file in a directory, making directories, etc. It does not contain any method to read or write data from a file. The File class extends the Object class and implements the Serializable and Comparable interfaces.

The FileReader class provides methods for reading character files. It contains methods for reading a single character, a fixed number of characters, or a whole stream of characters. Since these classes do not provide fast performance, they are usually wrapped within high-level reader objects such as a BufferedReader

The BufferedWriter class is used for fast writing operations of texts to a character-output stream. It can be used to write single characters, arrays, and strings of data. The size of buffer may or may not be specified. The BufferedWriter class has the newLine() method that is used to create platform-specific line separators, as some platforms do not support the new line character (‘\n’) to terminate lines.

The BufferedReader class is used for fast reading operations of texts from a character-input stream. It can be used to read single characters, arrays, and lines of data. The size of buffer may or may not be specified. The readLine() method of the BufferedReader class can be used to get the next line of characters from a file, and the skip(long n) method can be used to skip n number of characters.

The PrintWriter class extends the Writer class and implements the Closeable, Flushable, and Appendable interfaces. It is used for writing multiple-byte character sets and formatted representations of objects to a text-output stream. Methods in this class do not throw I/O exceptions

Do you have the right tools to get ahead this new school year? Earn more, do more, with an IT certification. Get certified – no matter if you are a fresh high school grad or in college or an IT professional. IT certifications help you stand out. Class shows. Let your credential do the talking.

For a limited time only, uCertify is offering a humongous discount of upto 50% ! Check out the offer!

Choose from over 300 test prep software for CompTIA, Microsoft, Oracle, IBM, Cisco, CCNA & many more. Nobody beats our breadth and depth of experience.

uCertify – the fastest way to IT certification with the right tools and the right price. It’s quite simply, the right thing to do.

Click here now to Save : uCertify’s Back 2 School Sale!

Hurry! Sale runs 8/17 through 8/25 only!

Happy Shopping & Happy Learning!

Your uCertify Team

http://www.ucertify.com

Constructor overloading is a technique in Java in which a class can have any number of constructors that differ in parameter lists. A constructor uses its arguments to initialize the new object’s state. The compiler differentiates these constructors by taking into account the number of parameters in the list and their types.

As constructors are not members of a class, they are not inherited by subclasses. Therefore, each of the subclasses must specifically implement any constructors it needs. However, a subclass can use the constructors of its superclass by using the super keyword.

The Console class extends the Object class and has convenience methods to read from and write to the console objects. Also, it 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 readPassword() method of the Console class is used to read a password from the underlying console. This method does not read any line-termination character. It returns null if an end of stream has been reached. There are two syntaxes for the readPassword() method as follows:

public char[] readPassword(): This method is used to read passwords from a console with echoing enabled.

public char[] readPassword(String fmt, Object… args): This method is used to read passwords from a console with echoing enabled in the given format.

Java provides two kinds of data type conversions, namely automatic and explicit. Automatic conversion takes place when the following two conditions are fulfilled:

• The two types are compatible.
• The destination type is larger than the source type.

When these two conditions are met, widening conversion takes place, i.e., a narrow data type is promoted to a wider one. For example, the value of byte type will be promoted to int, as int is wider than byte in width. However, in many cases, an automatic conversion cannot be performed. For example, an automatic conversion cannot be performed to convert int to byte, as int is wider than byte. In such cases, conversion is performed explicitly. The general form to perform such type of narrowing conversion is as follows:

(target-type) value

The main() method is the entry point for Java applications. The interpreter starts the execution of the program from the main() method. A Java application can have any number of classes, but only one of them includes the main() method that initiates the execution.

The signatures for the main() method are as follows:

• public static void main (String args[])
• public static void main (String[] args)
• public static void main (String []args)
• public static void main (String args)

where the keyword public is an access specifier that declares the main() method as unprotected, making it accessible to all other classes.

The keyword static makes the method static, so that it may be executed without constructing an instance of the corresponding class.

The args array contains an argument that the user might enter on the command line.

Inheritance is a process through which a class inherits the properties of another class. An inheritance is a relationship that can be created by extending a class in Java. A class inherits general attributes from its parent class, and adds those qualities that make it unique within the class.

Inheritance is used mainly for the following purposes:

• Code reuse
• Polymorphism

A Web service is defined by W3C as a software system designed to support interoperable machine-to-machine interaction over a network. Following are the two types of Web services:

1. Simple Web Service: It provides a request/response type of functionality and does not support transactions. It has the following characteristics:
   1. Point to point
   2. RPC and messaging based: It involves calling of a remote procedure and uses XML messaging.
   3. Non-transactional: It involves a simple request followed by a response to the client.
   4. Web security
2. Complex Web Service: It provides the framework for business-to-business collaborations and business process management. It acquires the following characteristics:
   1. Multi-party: It involves multiple business partners.
   2. Collaboration and workflow
   3. Transactional: All services run under transactional control spanning servers.
   4. Sophisticated security: It uses digital signatures for authentication and access control.
   5. Conversation state: It maintains a conversation state with the client, obtains the context, and shares it with collaborators.

A Web service is a unit of application logic that can be accessible via standard protocols. A Web service is defined by the W3C as a software system designed to support interoperable machine-to-machine interaction over a network. Web services are frequently just Web APIs that can be accessed over a network, such as the Internet, and executed on a remote system hosting the requested services. Remote clients use XML for data transport and SOAP for using services.

A Web service must have the following characteristics:

1. It must be registered with a central repository so that the client can look up it for a desired service.
2. It contains a public interface for the client to invoke services.
3. It should use standard protocols for communication.
4. It should be accessible over the Web.
5. It should support loose coupling with distributed systems so that the system running on different technologies can cooperate with each other.

The W3C Web service definition encompasses many different systems, but in common usage, the term refers to clients and servers that communicate over the HTTP protocol used on the Web. Such services tend to fall into one of two camps: Big Web Services and RESTful Web Services. Big Web Services use XML messages that follow the SOAP standard and have been popular with traditional enterprise. RESTful Web services have been regaining popularity, particularly with Internet companies. These also meet the W3C definition, and are often better integrated with HTTP than SOAP-based services.

Universal Description, Discovery and Integration (UDDI) is a platform-independent, XML-based registry for businesses worldwide to list themselves on the Internet. UDDI is an open industry initiative, sponsored by OASIS, enabling businesses to publish service listings and discover each other and define how the services or software applications interact over the Internet. A UDDI business registration consists of three components:

White Pages address, contact, and known identifiers.
Yellow Pages industrial categorizations based on standard taxonomies.
Green Pages technical information about services exposed by the business.

UDDI was originally proposed as a core Web service standard. It is designed to be interrogated by SOAP messages and to provide access to Web Services Description Language documents describing the protocol bindings and message formats required to interact with the Web services listed in its directory.

The Web Services Description Language is an XML-based language that provides a model for describing Web services. The current version of the specification is 2.0; version 1.1 has not been endorsed by the W3C, but version 2.0 is a W3C recommendation. WSDL 1.2 was renamed WSDL 2.0 because of its substantial differences from WSDL 1.1. By accepting binding to the HTTP request methods (not only GET and POST as in version 1.1), WSDL 2.0 specification offers better support for restful web services, and is much simpler to implement. According to W3C, WSDL 1.2 is easier and more flexible for developers than the previous version. WSDL 1.2 attempts to remove non-interoperable features and has also defined the better HTTP 1.1 binding. WSDL 1.2 was not supported by most of the SOAP servers/vendors.

WSDL 1.2 was actually renamed to WSDL 2.0 because it had substantial differences with WSDL 1.1. The improvements are as follows: