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• The UiBinder is a framework designed to SEPARATE Functionality and View of User Interface.
• The UiBinder framework allows developers to build gwt applications as HTML pages with GWT widgets configured throughout them.
• The UiBinder framework makes easier collaboration with UI designers who are more comfortable with XML, HTML and CSS than Java source code.
• The UIBinder provides a DECLARATIVE way of defining User Interface.
• The UIBinder seperates the programmic LOGIC from UI.
• The UIBinder is similar to what JSP is to Servlets.

GWT provides THREE ways to create custom user interface elements. There are three general strategies to FOLLOW −

• Create a widget by extending COMPOSITE Class − This is the most COMMON and easiest way to create custom widgets. Here you can use existing widgets to create composite view with custom properties.
• Create a widget using GWT DOM API in JAVA − GWT basic widgets are created in this way. Still its a very complicated way to create custom widget and should be used cautiously.
• Use JavaScript and wrap it in a widget using JSNI − This should generally only be done as a last resort. Considering the cross-browser implications of the native methods, it becomes very complicated and also becomes more DIFFICULT to debug.

GWT provides three ways to create custom user interface elements. There are three general strategies to follow −

SystemLogHandler LOGS to stdout and these MESSAGES can only be SEEN in DEVELOPMENT Mode in the DevMode window.

SystemLogHandler logs to stdout and these messages can only be seen in Development Mode in the DevMode window.

DEVELOPMENTMODELOGHANDLER logs by CALLING METHOD GWT.log. These MESSAGES can only be seen in DEVELOPMENT Mode in the DevMode window.

DevelopmentModeLogHandler logs by calling method GWT.log. These messages can only be seen in Development Mode in the DevMode window.

ConsoleLogHandler LOGS to the JAVASCRIPT CONSOLE, which is USED by Firebug Lite (for IE), Safari and Chrome.

ConsoleLogHandler logs to the javascript console, which is used by Firebug Lite (for IE), Safari and Chrome.

FIREBUGLOGHANDLER LOGS to FIREBUG CONSOLE.

FirebugLogHandler logs to Firebug console.

PopupLogHandler logs to the POPUP which resides in the UPPER left HAND corner of APPLICATION when this handler is enabled.

PopupLogHandler logs to the popup which resides in the upper left hand corner of application when this handler is enabled.

This HANDLER sends log messages to the SERVER, where they will be LOGGED using the server side LOGGING mechanism.

This handler sends log messages to the server, where they will be logged using the server side logging mechanism.

extend-property TAG with attribute name SET as locale and VALUES as language specific locale, say de for GERMAN locale.

extend-property tag with attribute name set as locale and values as language specific locale, say de for german locale.

This technique is the most powerful among the THREE techniques. Implementing Localizable ALLOWS us to create LOCALIZED versions of CUSTOM TYPES. It's an advanced internationalization technique.

This technique is the most powerful among the three techniques. Implementing Localizable allows us to create localized versions of custom types. It's an advanced internationalization technique.

This technique is very flexible but slower than static string internationalization. Host page CONTAINS the localized strings therefore, applications are not required to be RECOMPILED when we ADD a NEW locale. If GWT application is to be integrated with an existing server-side localization SYSTEM, then this technique is to be used.

This technique is very flexible but slower than static string internationalization. Host page contains the localized strings therefore, applications are not required to be recompiled when we add a new locale. If GWT application is to be integrated with an existing server-side localization system, then this technique is to be used.

This TECHNIQUE is most prevalent and requires very little overhead at runtime; is a very EFFICIENT technique for translating both constant and parameterized strings;SIMPLEST to IMPLEMENT. Static string internationalization uses standard Java properties files to store translated strings and parameterized messages, and strongly-typed Java interfaces are created to retrieve their VALUES.

This technique is most prevalent and requires very little overhead at runtime; is a very efficient technique for translating both constant and parameterized strings;simplest to implement. Static string internationalization uses standard Java properties files to store translated strings and parameterized messages, and strongly-typed Java interfaces are created to retrieve their values.

GWT provides THREE ways to INTERNATIONALIZE a GWT APPLICATION −

1. Static STRING Internationalization.
2. Dynamic String Internationalization.
3. Localizable Interface.

GWT provides three ways to internationalize a GWT application −

A JAVA DATA object should IMPLEMENT isSerializable INTERFACE so that it can be transferred over the wire in GWT RPC.

A java data object should implement isSerializable interface so that it can be transferred over the wire in GWT RPC.

FOLLOWING are the three components used in GWT RPC COMMUNICATION MECHANISM:

• A remote service (server-side servlet) that runs on the server.
• Client code to invoke that service.
• Java data objects which will be passed between client and server.
• GWT client and server both serialize and deserialize data automatically so developers are not REQUIRED to serialize/deserialize objects and data objects can travel over HTTP.

Following are the three components used in GWT RPC communication mechanism:

• RPC, Remote PROCEDURE Call is the mechansim used by GWT in which client code can directly executes the server side methods.
• GWT RPC is servlet BASED.
• GWT RPC is asynchronous and client is never blocked during communication.
• Using GWT RPC Java OBJECTS can be sent directly between the client and the server (which are automatically serialized by the GWT FRAMEWORK).
• Server-side servlet is termed as service.
• Remote procedure call that is calling methods of server side servlets from client side code is referred to as invoking a service.

•Create a folder for the application (e.g. withoutbook)
•Run webAppCreator in the NEWLY CREATED folder
–webAppCreator TAKES a MODULE name (here 'withoutbook' is the module name with a package prefix)

•Create a folder for the application (e.g. withoutbook)
•Run webAppCreator in the newly created folder
–webAppCreator takes a module name (here 'withoutbook' is the module name with a package prefix)

Run ant build in the root folder of the application. By default gwt compiler creates optimized JS files for some BROWSERS. 
: Disadvantage is it takes a lot of time to COMPILE each change because of the permutations 
Steps:
1) OPEN COMMAND prompt
2) GO to the application root folder
3) Run command as "ant build"
Then you can see compile logs are coming. If you see BUILD SUCCESSFUL it means no error in your application. If BUILD FAILED it means there is an error in your application.

Run ant build in the root folder of the application. By default gwt compiler creates optimized JS files for some browsers. 
: Disadvantage is it takes a lot of time to compile each change because of the permutations 
Steps:
1) Open command prompt
2) Go to the application root folder
3) Run command as "ant build"
Then you can see compile logs are coming. If you see BUILD SUCCESSFUL it means no error in your application. If BUILD FAILED it means there is an error in your application.

•To REDUCE the compilation TIME, choose favorite browser and add the user.agent property in the module configuration file.
Values: ie6,ie8,gecko1_8,SAFARI,opera
module.gwt.xml:
<module..>
<INHERITS...>
<set property name="user.agent" value="ie8,opera">
</module..>

•To reduce the compilation time, choose favorite browser and add the user.agent property in the module configuration file.
Values: ie6,ie8,gecko1_8,safari,opera
module.gwt.xml:
<module..>
<inherits...>
<set property name="user.agent" value="ie8,opera">
</module..>

There are two MODES: Development mode and Web mode.
Development Mode: ALLOWS to DEBUG the JAVA code of your application directly via the standard Java debugger. 
Web mode: the application is translated into HTML and Javascript code and can be deployed to a webserver.

There are two modes: Development mode and Web mode.
Development Mode: allows to debug the Java code of your application directly via the standard Java debugger. 
Web mode: the application is translated into HTML and Javascript code and can be deployed to a webserver.

GWT applications are described as modules. A module "modulename" is described by a configuration file "modulename.gwt.xml". Each module can define one or more Entry point classes.
An entry point is the starting point for a GWT application, similar to the main method in a standard Java PROGRAM. A Java class which is an entry point must implement the interface "com.google.gwt.core.client.EntryPoint" which defines the method onModuleLoad(). 
The module is connected to a HTML page, which is called "host page". The code for a GWT web application executes WITHIN this HTML document. 
The HTML page can define "DIV" containers to which the GWT application can assign UI components or the GWT UI components are simply ASSIGNED to the body tag of the HTML page.

GWT applications are described as modules. A module "modulename" is described by a configuration file "modulename.gwt.xml". Each module can define one or more Entry point classes.
An entry point is the starting point for a GWT application, similar to the main method in a standard Java program. A Java class which is an entry point must implement the interface "com.google.gwt.core.client.EntryPoint" which defines the method onModuleLoad(). 
The module is connected to a HTML page, which is called "host page". The code for a GWT web application executes within this HTML document. 
The HTML page can define "div" containers to which the GWT application can assign UI components or the GWT UI components are simply assigned to the body tag of the HTML page.

The look and FEEL of a GWT application can be customized via CSS files. Each widget in GWT can be given a HTML "DIV" container and can therefore be INDIVIDUALLY styled by CSS. You USE the Java method SETSTYLE(String s) for this.

The look and feel of a GWT application can be customized via CSS files. Each widget in GWT can be given a HTML "div" container and can therefore be individually styled by CSS. You use the Java method setStyle(String s) for this.

Two ways of running the application:
1) Create a war file and DEPLOY in any app server or
2) Run ant hosted in the COMMAND prompt. And click on the ‘LAUNCH Default BROWSER’.

Two ways of running the application:
1) Create a war file and deploy in any app server or
2) Run ant hosted in the command prompt. And click on the ‘Launch Default Browser’.

The String class is CONSIDERED as IMMUTABLE, so that once it is created a String OBJECT cannot be changed. If there is a NECESSITY to make ALOT of modifications to Strings of characters then StringBuffer should be used.

The String class is considered as immutable, so that once it is created a String object cannot be changed. If there is a necessity to make alot of modifications to Strings of characters then StringBuffer should be used.

Use StringBuilder whenever POSSIBLE because it is faster than STRINGBUFFER. But, if THREAD SAFETY is necessary then use StringBuffer objects.

Use StringBuilder whenever possible because it is faster than StringBuffer. But, if thread safety is necessary then use StringBuffer objects.

java.util.regex PACKAGE

java.util.regex package

It is POSSIBLE to define a method that will be called just before an object's final destruction by the GARBAGE collector. This method is called FINALIZE( ), and it can be used to ensure that an object terminates CLEANLY.

It is possible to define a method that will be called just before an object's final destruction by the garbage collector. This method is called finalize( ), and it can be used to ensure that an object terminates cleanly.

Object is a RUNTIME entity and it’s STATE is STORED in fields and behavior is shown via methods. Methods OPERATE on an object's internal state and SERVE as the primary mechanism for object-to-object communication.

Object is a runtime entity and it’s state is stored in fields and behavior is shown via methods. Methods operate on an object's internal state and serve as the primary mechanism for object-to-object communication.

A class is a BLUE print from which INDIVIDUAL OBJECTS are created. A class can contain fields and methods to describe the BEHAVIOR of an object.

A class is a blue print from which individual objects are created. A class can contain fields and methods to describe the behavior of an object.

Variables defined INSIDE methods, CONSTRUCTORS or blocks are called LOCAL variables. The variable will be declared and INITIALIZED within the METHOD and it will be destroyed when the method has completed.

Variables defined inside methods, constructors or blocks are called local variables. The variable will be declared and initialized within the method and it will be destroyed when the method has completed.

INSTANCE VARIABLES are variables WITHIN a class but outside any METHOD. These variables are instantiated when the class is loaded.

Instance variables are variables within a class but outside any method. These variables are instantiated when the class is loaded.

These are variables declared with in a class, OUTSIDE any METHOD, with the static KEYWORD.

These are variables declared with in a class, outside any method, with the static keyword.

Singleton class control OBJECT CREATION, limiting the number to one but ALLOWING the flexibility to CREATE more objects if the SITUATION changes.

Singleton class control object creation, limiting the number to one but allowing the flexibility to create more objects if the situation changes.

Constructor GETS INVOKED when a NEW object is CREATED. Every class has a constructor. If we do not explicitly write a constructor for a class the java compiler BUILDS a default constructor for that class.

Constructor gets invoked when a new object is created. Every class has a constructor. If we do not explicitly write a constructor for a class the java compiler builds a default constructor for that class.

An OBJECT is FIRST DECLARED, then INSTANTIATED and then it is INITIALIZED.

An Object is first declared, then instantiated and then it is initialized.

DEFAULT VALUE of BYTE DATATYPE is 0.

Default value of byte datatype is 0.

Default VALUE of FLOAT and double DATATYPE in different as COMPARED to C/C++. For float its 0.0f and for double it’s 0.0d

Default value of float and double datatype in different as compared to C/C++. For float its 0.0f and for double it’s 0.0d

This DATA type is used to save space in LARGE ARRAYS, mainly in place of integers, since a byte is FOUR times smaller than an int.

This data type is used to save space in large arrays, mainly in place of integers, since a byte is four times smaller than an int.

Class VARIABLES ALSO known as static variables are declared with the static KEYWORD in a class, but outside a method, CONSTRUCTOR or a block.

Class variables also known as static variables are declared with the static keyword in a class, but outside a method, constructor or a block.

Java provides access modifiers to set access levels for classes, variables, methods and constructors. A MEMBER has package or default ACCESSIBILITY when no accessibility modifier is SPECIFIED.

Java provides access modifiers to set access levels for classes, variables, methods and constructors. A member has package or default accessibility when no accessibility modifier is specified.

Variables, METHODS and constructors which are declared protected in a superclass can be ACCESSED only by the subclasses in other package or any CLASS within the package of the protected MEMBERS' class.

Variables, methods and constructors which are declared protected in a superclass can be accessed only by the subclasses in other package or any class within the package of the protected members' class.

VARIABLES USED in a switch statement can only be a STRING, ENUM, byte, short, int, or char.

Variables used in a switch statement can only be a string, enum, byte, short, int, or char.

• NETBEANS 
• ECLIPSE

It is designed to ADAPT to an EVOLVING environment. Java programs can CARRY extensive amount of run-time INFORMATION that can be used to verify and RESOLVE accesses to objects on run-time.

It is designed to adapt to an evolving environment. Java programs can carry extensive amount of run-time information that can be used to verify and resolve accesses to objects on run-time.

Java uses Just-In-Time compiler to ENABLE HIGH performance. Just-In-Time compiler is a program that TURNS Java BYTECODE, which is a program that contains instructions that must be interpreted into instructions that can be sent directly to the PROCESSOR.

Java uses Just-In-Time compiler to enable high performance. Just-In-Time compiler is a program that turns Java bytecode, which is a program that contains instructions that must be interpreted into instructions that can be sent directly to the processor.

It’s COMPILER generates an architecture-neutral object file format, which makes the COMPILED code to be executable on MANY processors, with the presence of Java RUNTIME SYSTEM.

It’s compiler generates an architecture-neutral object file format, which makes the compiled code to be executable on many processors, with the presence of Java runtime system.

Some features INCLUDE

• Object Oriented
• Platform Independent
• Robust
• INTERPRETED
• Multi-threaded

Some features include

Java runs on a VARIETY of platforms, such as Windows, Mac OS, and the various VERSIONS of UNIX/Linux LIKE HP-Unix, Sun Solaris, REDHAT Linux, Ubuntu, CentOS, etc.

Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX/Linux like HP-Unix, Sun Solaris, Redhat Linux, Ubuntu, CentOS, etc.

Java is a high-level programming language originally developed by SUN Microsystems and RELEASED in 1995. Java runs on a variety of PLATFORMS, such as Windows, Mac OS, and the various versions of UNIX.

Java is a high-level programming language originally developed by Sun Microsystems and released in 1995. Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX.

Doctype tag is not a HTML tag, it is just an INSTRUCTION that is passed to the web BROWSER to check for the information that is being PROVIDED by the markup language in which the page is WRITTEN. Doctype is sometimes referred as Document type definition (DTD) that describes some rules that has to be FOLLOWED while writing the markup language so to make the web browser understand the language and the content correctly. Doctype is very important to be placed in the beginning of the HTML and before the <HTML> tag to allow easy rendering of the pages that are used.

Doctype tag is not a HTML tag, it is just an instruction that is passed to the web browser to check for the information that is being provided by the markup language in which the page is written. Doctype is sometimes referred as Document type definition (DTD) that describes some rules that has to be followed while writing the markup language so to make the web browser understand the language and the content correctly. Doctype is very important to be placed in the beginning of the HTML and before the <HTML> tag to allow easy rendering of the pages that are used.