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We can RESTRICT inheritance for class by following steps.
1. By USING final keyword
2. If we make all method final, then we cannot OVERRIDE that.
3. By using PRIVATE constructors
4. By using Javadoc COMMENT (//)

We can restrict inheritance for class by following steps.
1. By using final keyword
2. If we make all method final, then we cannot override that.
3. By using private constructors
4. By using Javadoc comment (//)

The map interface is not compatible with the Collection interface. Because Map REQUIRES key as well as value, for example: if we want to add key-value pair so we will use PUT(OBJECT key , Object value). There are two parameters required to add an element to HashMap object. In Collection interface add(Object o) has only ONE parameter.
The other reasons are Map supports valueSet, keySet as well as other suitable methods which have just different VIEWS from the Collection interface.

The map interface is not compatible with the Collection interface. Because Map requires key as well as value, for example: if we want to add key-value pair so we will use put(Object key , Object value). There are two parameters required to add an element to HashMap object. In Collection interface add(Object o) has only one parameter.
The other reasons are Map supports valueSet, keySet as well as other suitable methods which have just different views from the Collection interface.

TRANSIENT: In Java, it is used to specify the VARIABLE is not being serialized. Serialization is a process of SAVING an object’s state in Java. When we want to persist and the object’s state by default, all instance VARIABLES in the object are STORED. In some cases, if we want to avoid persisting few variables because we don’t have the necessity to transfer across the network. So, declare those variables as transient. If the variable is confirmed as transient, then it will not be persisted.

Transient keyword is used with that instance variable which will not participate in the serialization process. We cannot use static with a transient variable as they are part of the instance variable.
Volatile: Volatile keyword is used with only variable in Java and it guarantees that the value of the volatile variable will always be read from main memory and not from Thread’s local cache, it can be static.

Transient: In Java, it is used to specify the variable is not being serialized. Serialization is a process of saving an object’s state in Java. When we want to persist and the object’s state by default, all instance variables in the object are stored. In some cases, if we want to avoid persisting few variables because we don’t have the necessity to transfer across the network. So, declare those variables as transient. If the variable is confirmed as transient, then it will not be persisted.

Transient keyword is used with that instance variable which will not participate in the serialization process. We cannot use static with a transient variable as they are part of the instance variable.
Volatile: Volatile keyword is used with only variable in Java and it guarantees that the value of the volatile variable will always be read from main memory and not from Thread’s local cache, it can be static.

The Vector CLASS provides the ability to EXECUTE a growable ARRAY of objects. Vector proves to be very useful if you don’t know the size of the array in ADVANCE, or we need one that can CHANGE sizes over the lifetime of a program.

The Vector class provides the ability to execute a growable array of objects. Vector proves to be very useful if you don’t know the size of the array in advance, or we need one that can change sizes over the lifetime of a program.

Java.Lang.throwable – It is the super CLASS of all exception CLASSES and all exception classes are derived from this BASE class.

Java.Lang.throwable – It is the super class of all exception classes and all exception classes are derived from this base class.

Java PROVIDES a Collection API which provides many USEFUL methods which can be applied to a set of objects. Some of the important classes provided by Collection API INCLUDE ArrayList, HashMap, TreeSet, and TREEMAP.

Java provides a Collection API which provides many useful methods which can be applied to a set of objects. Some of the important classes provided by Collection API include ArrayList, HashMap, TreeSet, and TreeMap.

In JAVA, there is no way to find out the ACTUAL size of an OBJECT on the HEAP.

In Java, there is no way to find out the actual size of an object on the heap.

Usually, we called ENUMERATION as an ENUM. An enumeration is an interface containing methods for ACCESSING the original data structure from which the enumeration is obtained. It allows SEQUENTIAL access to all the elements STORED in the collection.

Usually, we called enumeration as an enum. An enumeration is an interface containing methods for accessing the original data structure from which the enumeration is obtained. It allows sequential access to all the elements stored in the collection.

JAXP: – Stands for Java API for XML Processing. This provides a common interface for creating and using DOM, SAX, and XSLT APIs in Java regardless of which vendor’s implementation is actually being used.
JAXB: – It Stands for Java API for XML Binding. This STANDARD DEFINES a SYSTEM for a script out Java objects as XML and for creating Java objects from XML STRUCTURES.

JAXP: – Stands for Java API for XML Processing. This provides a common interface for creating and using DOM, SAX, and XSLT APIs in Java regardless of which vendor’s implementation is actually being used.
JAXB: – It Stands for Java API for XML Binding. This standard defines a system for a script out Java objects as XML and for creating Java objects from XML structures.

STRUTS 1 actions are a singleton. So all THREADS OPERATE on the single action object and hence make it thread-unsafe.Struts 2 actions are not a singleton and a new action object copy are CREATED each time a new action REQUEST is made and hence it threads safe.

Struts 1 actions are a singleton. So all threads operate on the single action object and hence make it thread-unsafe.Struts 2 actions are not a singleton and a new action object copy are created each time a new action request is made and hence it threads safe.

Static loading – Classes are loaded STATICALLY with operator “new”.
Dynamic class loading – It is a TECHNIQUE for programmatically INVOKING the functions of a class loader at RUN time.
The syntax isClass.forName (Test className);

Static loading – Classes are loaded statically with operator “new”.
Dynamic class loading – It is a technique for programmatically invoking the functions of a class loader at run time.
The syntax isClass.forName (Test className);

Pointers are SUSCEPTIBLE and slight carelessness in their USE may result in memory PROBLEMS and hence JAVA basically manages their use.

Pointers are susceptible and slight carelessness in their use may result in memory problems and hence Java basically manages their use.

It is a form of METADATA and it provides data about a PROGRAM that is not part of the program itself. An annotation has no direct effect on the operation of the code they annotate.
Uses of Annotations :
• Information for the compiler — It can be USED by the compiler to detect errors or suppress warnings.
• Compile-time and deployment-time processing — some software tools can process annotation information to generate code, XML FILES, and so forth.
• RUNTIME processing — few annotations are available to be examined at runtime.

It is a form of metadata and it provides data about a program that is not part of the program itself. An annotation has no direct effect on the operation of the code they annotate.
Uses of Annotations :
• Information for the compiler — It can be used by the compiler to detect errors or suppress warnings.
• Compile-time and deployment-time processing — some software tools can process annotation information to generate code, XML files, and so forth.
• Runtime processing — few annotations are available to be examined at runtime.

A CLASS which contains the abstract keyword in its declaration is known as abstract class. It can have abstract and non-abstract methods (METHOD with body).
1. This class can have public, private, PROTECTED or constants and default variables.
2. It needs to be extended and its method implemented. It cannot be instantiated.
3. If a class has at LEAST one abstract method, then the class must be declared abstract.

A class which contains the abstract keyword in its declaration is known as abstract class. It can have abstract and non-abstract methods (method with body).
1. This class can have public, private, protected or constants and default variables.
2. It needs to be extended and its method implemented. It cannot be instantiated.
3. If a class has at least one abstract method, then the class must be declared abstract.

Yes, we can import the same package/class multiple TIMES. Compiler and JVM are not complaining about it. And the JVM will internally LOAD the class only once no matter how many times we import the same class.

Yes, we can import the same package/class multiple times. Compiler and JVM are not complaining about it. And the JVM will internally load the class only once no matter how many times we import the same class.

If we have visited WEBSITE to SEARCHING the information, we will get the information in different languages and in different formats when a client makes an HTTP request to a server, the client can also specify the media types here. The client can specify what it can accept back from the host and on the basis of availability the host will RETURN to the client. This is known as CONTENT negotiation because client and server negotiated on the language and format of the content to be SHARED.

If we have visited website to searching the information, we will get the information in different languages and in different formats when a client makes an HTTP request to a server, the client can also specify the media types here. The client can specify what it can accept back from the host and on the basis of availability the host will return to the client. This is known as content negotiation because client and server negotiated on the language and format of the content to be shared.

CLONE() – This method helps to create and return a copy of the object.
equals() – This method helps to compare.
finalize() – CALLED by the garbage collector on an object.
getClass() – It helps to return the runtime CLASS of an object.
hashCode() – Helps to return a hash code value for the object.
toString() – helps to return a string representation of the object.
notify(), notifyAll(), and wait() – It helps to synchronize the activities of independently RUNNING threads in a PROGRAM.

clone() – This method helps to create and return a copy of the object.
equals() – This method helps to compare.
finalize() – Called by the garbage collector on an object.
getClass() – It helps to return the runtime class of an object.
hashCode() – Helps to return a hash code value for the object.
toString() – helps to return a string representation of the object.
notify(), notifyAll(), and wait() – It helps to synchronize the activities of independently running threads in a program.

The ADVANTAGES of JSON over XML are
1. JSON is Lighter and faster than XML.
2. Better understandable.
3. Easy to parse and conversion to OBJECTS for information consumption.
4. Support multiple data TYPES – JSON support string, number, array, Boolean but XML data are all STRINGS.

The advantages of JSON over XML are
1. JSON is Lighter and faster than XML.
2. Better understandable.
3. Easy to parse and conversion to objects for information consumption.
4. Support multiple data types – JSON support string, number, array, Boolean but XML data are all strings.

Expansion of JSON is “JavaScript Object Notation”, It is a much lighter and readable ALTERNATIVE to XML. It is an INDEPENDENT and easily parse-able in all PROGRAMMING languages. It is primarily used for Communicating between CLIENT – server or server -server communication. It is a much lighter and readable alternative to XML.

Expansion of JSON is “JavaScript Object Notation”, It is a much lighter and readable alternative to XML. It is an independent and easily parse-able in all programming languages. It is primarily used for Communicating between client – server or server -server communication. It is a much lighter and readable alternative to XML.

We cannot inherit a CONSTRUCTOR. We create an instance of a subclass using a constructor of one of its superclass. Because OVERRIDE the superclass constructor is not our wish so that, we override a superclass constructor, then we destroy the ENCAPSULATION abilities of the LANGUAGE.

We cannot inherit a constructor. We create an instance of a subclass using a constructor of one of its superclass. Because override the superclass constructor is not our wish so that, we override a superclass constructor, then we destroy the encapsulation abilities of the language.

We can fetch records from the DATABASE by the query method of JdbcTemplate. There are TWO INTERFACES to do this:
1. ResultSetExtractor
2. ROWMAPPER

We can fetch records from the database by the query method of JdbcTemplate. There are two interfaces to do this:
1. ResultSetExtractor
2. RowMapper

IOC container is responsible to:
• CREATE the instance
• CONFIGURE the instance, and
• assemble the DEPENDENCIES

IOC container is responsible to:
• create the instance
• configure the instance, and
• assemble the dependencies

A cookie is a small PIECE of information, this piece of information sends to the browser by a web server. The browser stores the cookies for every Web server in a local file. In a future request or future REFERENCE, the browser sends all stored cookies for that DETAILED Web server.
The difference between cookies and sessions are:
• The session is working, regardless of the SETTINGS on the client browser. The client may have SELECTED to disable cookies.
• The session and cookies also differ in storing the amount of information. The HTTP session is able to store any Java object, while a cookie can only store String objects.

A cookie is a small piece of information, this piece of information sends to the browser by a web server. The browser stores the cookies for every Web server in a local file. In a future request or future reference, the browser sends all stored cookies for that detailed Web server.
The difference between cookies and sessions are:
• The session is working, regardless of the settings on the client browser. The client may have selected to disable cookies.
• The session and cookies also differ in storing the amount of information. The HTTP session is able to store any Java object, while a cookie can only store String objects.

JSP IMPLICIT OBJECTS are those Java objects that the JSP Container makes available to developers in every PAGE. A developer can able to CALL them directly, without being explicitly declared. JSP Implicit Objects are also known as pre-defined variables. The following objects are considered implicit in a JSP page:
• application
• page
• request
• response
• session
• exception
• out
• config
• pageContext

JSP implicit objects are those Java objects that the JSP Container makes available to developers in every page. A developer can able to call them directly, without being explicitly declared. JSP Implicit Objects are also known as pre-defined variables. The following objects are considered implicit in a JSP page:
• application
• page
• request
• response
• session
• exception
• out
• config
• pageContext

The EXPRESSION LANGUAGE is used in JSP to SIMPLIFY the accessibility of objects and It PROVIDES many objects that can be used directly like PARAM, requestScope, sessionScope, applicationScope, request, session etc.

The expression language is used in JSP to simplify the accessibility of objects and It provides many objects that can be used directly like param, requestScope, sessionScope, applicationScope, request, session etc.

• Custom tags can manipulate JSP content, but BEANS cannot.
• Composite operations can be reduced to a considerably simpler form with custom tags than with beans.
• Custom tags require REASONABLY a BIT more WORK to set up than do beans.
• Custom tags are available only in JSP 1.1 and so on, but beans can be used in all JSP 1.x VERSIONS

• Custom tags can manipulate JSP content, but beans cannot.
• Composite operations can be reduced to a considerably simpler form with custom tags than with beans.
• Custom tags require reasonably a bit more work to set up than do beans.
• Custom tags are available only in JSP 1.1 and so on, but beans can be used in all JSP 1.x versions

• This METHOD RETURNS a hash CODE VALUE (an integer number).
• And also returns the same integer number, if two keys (by calling equals() method) are same.
• But in sometimes two hash code numbers can have different or same keys.

We are using SYNCHRONIZED block because
• It HELPS to LOCK an object for EVERY shared resource.
• The scope of synchronized block is smaller than the method.

We are using Synchronized block because
• It helps to lock an object for every shared resource.
• The scope of synchronized block is smaller than the method.

We can make the Collection readOnly by USING the following lines code:

General : Collections.unmodifiableCollection(Collection c)Collections.unmodifiableMap(MAP m)

Collections.unmodifiableList(List L)

Collections.unmodifiableSet(Set s)

We can make the Collection readOnly by using the following lines code:

General : Collections.unmodifiableCollection(Collection c)Collections.unmodifiableMap(Map m)

Collections.unmodifiableList(List l)

Collections.unmodifiableSet(Set s)

Collections.synchronizedCollection(COLLECTION collectionObj) will CONVERT a GIVEN collection to SYNCHRONIZED collection.

Collections.synchronizedCollection(Collection collectionObj) will convert a given collection to synchronized collection.

In Hashtable , if two different KEYS have the same HASH value then it leads to hash -collision. A BUCKET of type LINKED LIST used to hold the different keys of same hash value.

In Hashtable , if two different keys have the same hash value then it leads to hash -collision. A bucket of type linked list used to hold the different keys of same hash value.

If we MARK a class as mutable=”false”, the class will be TREATED as an immutable class. The DEFAULT VALUE of mutable is “true”.

If we mark a class as mutable=”false”, the class will be treated as an immutable class. The default value of mutable is “true”.

The states of an object in hibernate are

1. Transient
2. Persistent
3. Detached

Transient: The object is in the transient STATE if it is just CREATED but has no primary key (IDENTIFIER) and it is not associated with the session.
Persistent: The object is in the persistent state if the session is OPEN, and we just saved the instance in the database or retrieved the instance from the database.
Detached: The object is in the detached state if the session is closed. After detached state, the object comes to persistent state if we call lock() or update() method.

The states of an object in hibernate are

Transient: The object is in the transient state if it is just created but has no primary key (identifier) and it is not associated with the session.
Persistent: The object is in the persistent state if the session is open, and we just saved the instance in the database or retrieved the instance from the database.
Detached: The object is in the detached state if the session is closed. After detached state, the object comes to persistent state if we call lock() or update() method.

The DISPATCHER Servlet class works as the front CONTROLLER in SPRING MVC.

The Dispatcher Servlet class works as the front controller in Spring MVC.

BINDING is the process of ASSOCIATING or REGISTERING a name for a REMOTE object, which can be used as a further, in ORDER to look up that remote object. A remote object can be associated with a name using the bind / rebind methods of the Naming class.

Binding is the process of associating or registering a name for a remote object, which can be used as a further, in order to look up that remote object. A remote object can be associated with a name using the bind / rebind methods of the Naming class.

. PRIVATE void sortUsingJava8(List NAMES){

Collections.sort(names, (p1, P2) -> p1.compareTo(p2));

}

. private void sortUsingJava8(List names){

Collections.sort(names, (p1, p2) -> p1.compareTo(p2));

}

A PERSON who COMBINES J2EE components and modules into deployable application UNITS.

A person who combines J2EE components and modules into deployable application units.

The process that verifies the identity of a user, DEVICE, or other entity in a computer SYSTEM, usually as a prerequisite to allowing access to resources in a system. The Java servlet specification requires THREE TYPES of AUTHENTICATION-basic, form-based, and mutual-and supports digest authentication.

The process that verifies the identity of a user, device, or other entity in a computer system, usually as a prerequisite to allowing access to resources in a system. The Java servlet specification requires three types of authentication-basic, form-based, and mutual-and supports digest authentication.

A QUALIFIER on an XML TAG that PROVIDES ADDITIONAL INFORMATION.

A qualifier on an XML tag that provides additional information.

A Java-based BUILD tool that can be extended USING Java CLASSES. The CONFIGURATION files are XML-based, calling out a target tree where various tasks GET executed.

A Java-based build tool that can be extended using Java classes. The configuration files are XML-based, calling out a target tree where various tasks get executed.

The PROCESS of SAVING the STATE of an OBJECT and RESTORING it.

The process of saving the state of an object and restoring it.

An XML file used to CONFIGURE RESOURCES for a Java Server Faces application, to define NAVIGATION rules for the application, and to register converters, Validator, listeners, RENDERS, and components with the application.

An XML file used to configure resources for a Java Server Faces application, to define navigation rules for the application, and to register converters, Validator, listeners, renders, and components with the application.

A VENDOR that provides the Java CLASSES that implement COMPONENTS' methods, JSP page definitions, and any REQUIRED deployment descriptors.

A vendor that provides the Java classes that implement components' methods, JSP page definitions, and any required deployment descriptors.

A software UNIT that consists of one or more CLASSES and an APPLICATION client DEPLOYMENT descriptor.

A software unit that consists of one or more classes and an application client deployment descriptor.

A CONTAINER that SUPPORTS APPLICATION CLIENT COMPONENTS.

A container that supports application client components.

A first-tier J2EE CLIENT component that executes in its own Java VIRTUAL machine. Application clients have ACCESS to some J2EE platform APIs.

A first-tier J2EE client component that executes in its own Java virtual machine. Application clients have access to some J2EE platform APIs.

A tag library that encapsulates core functionality common to many JSP applications. JSTL has support for common, structural tasks such as iteration and conditionals, TAGS for manipulating XML documents, internationalization and locale-specific FORMATTING tags, SQL tags, and functions.

A tag library that encapsulates core functionality common to many JSP applications. JSTL has support for common, structural tasks such as iteration and conditionals, tags for manipulating XML documents, internationalization and locale-specific formatting tags, SQL tags, and functions.

An extensible Web TECHNOLOGY that uses static DATA, JSP elements, and server-side JAVA objects to generate dynamic content for a client. Typically the static data is HTML or XML elements, and in MANY cases the client is a Web browser.

An extensible Web technology that uses static data, JSP elements, and server-side Java objects to generate dynamic content for a client. Typically the static data is HTML or XML elements, and in many cases the client is a Web browser.

A SIMPLE expression LANGUAGE used by a JavaServer Faces UI component tag attributes to bind the associated component to a bean property or to bind the associated component's value to a method or an external data SOURCE, such as a bean property. Unlike JSP EL expressions, JavaServer Faces EL expressions are EVALUATED by the JavaServer Faces implementation rather than by the Web CONTAINER.

A simple expression language used by a JavaServer Faces UI component tag attributes to bind the associated component to a bean property or to bind the associated component's value to a method or an external data source, such as a bean property. Unlike JSP EL expressions, JavaServer Faces EL expressions are evaluated by the JavaServer Faces implementation rather than by the Web container.

In SPRING DAO CLASSES only THROWS SQLEXCEPTION.

In spring DAO classes only throws SQLException.