Enterprise Spring

• Hitting the database
• Managing transactions
• Securing Spring
• Spring messaging
• Spring and Enterprise Java Beans
• Accessing Enterprise Services

Client-Side Spring

• Handling web requests
• Rendering web views
• Using Spring web flow
• Integrating with other web framework

JAVA Training in Kolkata

Kolkata is eastern India’s IT hub where there are more than 1600 IT companies working. These companies comprise of smaller, medium sized as well as bigger and MNCs like TCS, Capgemini, IBM, Ericson etc.

Most of the IT companies are based in Kolkata’s Salt Lake City. Because of being good IT environment and easy communication, most of the companies prefer Salt Lake City. But, there are several other IT companies also which are at other places of Kolkata.

Though smaller companies normally do not work on JAVA but medium size and bigger companies work on JAVA technology. So, if you learn JAVA properly there is high chance that you will get placement also. But it’s very important to understand that your concept of JAVA should be clear or else just doing JAVA class is not going to help you to get job.

Normally, thecompanies which work on JAVA technology have foreign clients. So, they need candidates having experience that have done projects on JAVA during training. We at Acesoftech Academy, a premier JAVA Training institute in Kolkata, pays special attention on projects. In this JAVA training you will do at least 3 projects. So that your concept of JAVA will be clear and you will get confidence on JAVA technology.

If you search JAVA Training canter in Kolkata, you will get several results of Java training Institute but what Acesoftech Academy sets apart from others is that we have dedicated and knowledge trainer having industry experience as well as great skill of JAVA training. If you are looking for good salaried package career. You can go for JAVA course. Because JAVA is the language which has been here for last 20 years.

WHY Acesoftech Academy for JAVA Training in Kolkata

• Acesoftech Academy is one of the Premier JAVA training institutes in Kolkata which guarantees you advanced and Industrial JAVA Training.
• The Course has been designed by JAVA expert.
• The trainer has done MCA and he has been training JAVA as well as working on JAVA for long.
• Minimum 3 projects along with this course. Projects are not optional but compulsory at our canter.
• Week-end classes are also available.
• Flexible time and flexible dates are available.
• Personal care and help in project also.
• Even your course is finished; our relation does not end here. You can also take help through phone, emails Facebook etc.
• We provide certificate also after completing the course.
• Fee hosting will be provided for live projects.

10 Reasons Why You Should Learn Java

• Java is high paying job programing language
• Java is platform independent and also Versatile
• Java is based on Popular OOPS pattern
• Java is ubiquitous, you find Java everywhere
• Several Java Development Tools
• Java applications can be for desktop, mobile as well as websites
• Huge Resources & Community Support
• Java has Rich API to work with
• Several new features has been added in Java 9 onwards
• Java is Easy to understand and it’s also Open Source

    Question and Answer




1. What is JAVA?

Java is the object-oriented high-level and secure programming language with high performance, Multithreaded, and portable programming language which is platform-independent.

2. Who developed JAVA and when?

in June 1991 James Gosling developed it.

3. What are the differences between C++ and Java?

1. C++
a)Platform dependent
b) Used for System Programming
c) Supports goto statement
d) It uses compiler only
2. JAVA
a)Platform independent
b) Used for application programming
c) Does not supports goto statement
d) It uses both compiler & interpreter


4. What do you mean by JVM (Java virtual machine)?

JVM is a virtual machine that allows the computer to run the Java program. JVM acts like a run-time engine which calls the main method present in the Java code. The Java code is totally compiled by JVM to convert it into Bytecode which is machine independent.

5. What is the difference between JDK, JRE, and JVM?

JVM: It is an abstract machine which provides the runtime environment to execute Java bytecode. It specifies the working of Java Virtual Machine and Oracle as well as some other companies provided its implementation. Its implementation is known as JRE.

JRE: JRE stands for Java Runtime Environment. It is the implementation of JVM. The JRE is a set of software tools which are used to develop Java applications and also to provide the runtime environment for it. It contains a set of libraries + other files that JVM uses at runtime.

JDK: JDK is an acronym for Java Development Kit. It is a software development environment which is used to develop Java applications and applets. It contains JRE + development tools.

6. What is JIT (Just-In-Time) compiler?

(JIT) compiler is used to improve the performance. JIT compiles parts of the bytecode that have similar functionality at the same time, and hence reduces the amount of time needed for compilation.

7. What do you mean by the term platform?

A platform is the hardware or software environment in which execution of a piece of software takes place. There are two types of platforms: software-based and hardware-based. Java provides the software-based platform

8. Is Java platform independent?

Yes. Java is a platform independent language. We can write java code on one platform and run it on another platform. For e.g. we can write and compile the code on windows and can run the generated bytecode on Linux or any other supported platform.

9. How many types of memory areas are allocated by JVM?

Many types:

1. Class(Method) Area: It stores per-class structures such as the runtime constant field, method data, and the code for methods.

2. Heap: It is the runtime data area in which an objects is assigned the memory.

3. Stack: It holds local variables and partial results, and plays a part in method invocation and return. Each thread has a private JVM stack which is created at the time of thread. A new frame is created each time a method is invoked and destroyed when its method invocation completes.

4. Program Counter Register: PC (program counter) register contains the address of the Java virtual machine instruction which is currently executed.

5. Native Method Stack: It contains all the native methods which are used in the creation of an application.

10. What gives Java its 'write once and run anywhere' nature?

Java compiler converts the Java programs into the class file (i.e.Byte Code) which is the intermediate language between source code and machine code. This bytecode is not platform dependent and can be executed on any computer

11. Is Empty.java file name a valid source file name?

Yes, Java allows to save our java file by .java only, we need to compile it by javac .java and run by java classname Let's take a simple example:
//save by .java only
class A{
public static void main(String args[]){
System.out.println("Hello java");
}
}
It will be compile by javac .java
It will run by java A


12. ) Explain public static void main(String args[])

public : It is an identifier which allows a Class, Method, Field to be accessible from anywhere.

static : static is a keyword which tells that this method can be accessed without creating the instance of the class.

void this main method returns no value.

main It is the name of the method from where a program initially starts.

String args[]: The args is an array of String type. This contains the command line arguments that we can pass while running the program.

13. What is javac ?

The javac is a compiler that compiles the source code of a program and generates bytecode.

14. What are the various access specifiers for Java classes?

The types of access specifiers for classes are:
1. Public : Class, Method, Field is accessible from anywhere.

2. Protected: Method, Field can be accessed from the same class to which they belong or from the sub-classes, and from the class of same package, but not from outside.

3. Default: Method, Field, class can be accessed only from the same package and not from outside of it's native package.

4. Private: Method, Field can be accessed from the same class to which they belong.

15. What is the base class of all classes?

In Java, among all the classes, java.lang.Object is the base class (super class).

16. What is a wrapper class in Java?

A wrapper class is a class that converts the primitive data type to the objects of their respective classes. For example, int is a primitive data type which is converted into its object class as Integer by the wrapper class.

17. What is Unicode?

Unicode defines a fully international character set that can represent all of the characters found in human languages or world’s writing system. Java uses Unicode to represent the characters.

18. What is the purpose of static methods and variables?

The static methods or variables are shared among all the objects of the class. The static is the part of the class and not of the object. The static variables not need to create the object. Therefore, static is used in the case, where we need to define variables or methods which are common to all the objects of the class.

19. What are Java Packages?

In Java, package is a collection of classes and interfaces which relates to each other as they are bundled together.

20. What is data encapsulation and what's its significance?

Encapsulation means the combining of behaviours and methods together in a single unit. It helps programmers to develop software with a modular approach as each object has its own set of methods and variables and performs all the functions independently with respect to other objects.

21. What is a singleton class? Give a practical example of its usage.

A singleton class in java can have only one instance and hence all its methods and variables belong to just one instance. Singleton class concept is useful for the situations when there is a need to limit the number of objects for a class.

22. What are Loops in Java?

In Java, Loops are used to execute a statement or a block of statement repeatedly.

23. How many kinds of Loops are there in Java?

In Java, there are three kinds of loops: For, while and do-while.

24. What is the difference between continue and break statement?

When a break keyword is used in a loop, loop is stop instantly while when continue keyword is used, current iteration is broken and loop continues with next iteration.

25. Does java support multiple inheritance? Why?

Java doesn't support multiple inheritance because to avoid ambiguity error. But through the interface, multiple inheritance in Java is possible.

26. What do you mean by Inheritance?

Inheritance is a mechanism by which one object of a class acquires all the properties and behaviours of another object of base or another class.

27. Why is Inheritance used in Java?

In Java, Inheritance is used to create new classes that are built upon the classes which are already exists. Actually we inherit from the parent class to reuse methods and all the fields of the parent class.

28. How many types of inheritance are there?

There are five types of inheritance in Java. i. Single-level inheritance ii.Multi-level inheritance iii.Multiple Inheritance iv. Hierarchical Inheritance v.Hybrid Inheritance

29. What is a pointer? Does Java support pointers?

Pointer is a reference handle to a memory location. Java doesn't support the usage of pointers because improper handling of pointers leads to leakage of memory and reliability issues.

30.What is the difference between double and float variables in Java?

In java, Double takes 8 bytes in memory while Float takes 4 bytes in memory. Double is twice precision floating point decimal number while float is single precision decimal number.

31. What is Final Keyword in Java?

In java, Final keyword is used to declare a constant. Once a value assigned which can't be changed.

32. What is ternary operator?

Conditional operator is also called Ternary operator which is used to assign a value to a variable based on a Boolean value evaluation (i.e. true or false). It is represented as “?”.

33. Can main() method in Java can return any data?

In java, main() method can't return any value and hence it is declared as return type “void”.

34. Does Importing a package imports its sub-packages as well in Java?

In java, when a package is imported, its sub-packages aren't imported and if required to import sub-packages, the developer needs to import them separately.

35. Can we declare the main method of our class as private?

In java, main method is always public static in order to run any application properly. If main method is declared as private, it will not get executed and will give a runtime error.

36. can we pass argument to a function by reference instead of pass by value?

In java, we can pass argument to a function only by value and not by reference

37. Is it compulsory for a Try Block to be followed by a Catch Block in Java for Exception handling?

After every Try block there should be either Catch block or Finally block or both. To catch and display any error during execution a Catch block or Finally block.

38. Is there any way to skip Finally block of exception even if some exception occurs in the exception block?

If an error is occurred in Try block then the control passes to catch block if it exists otherwise to finally block. The only way to avoid the use of Finally block is by using the following line of code at the end of try block: System.exit(0);

39. How is Final different from Finally and Finalize?

Final is a keyword which can be applied to a class or a method or a variable. Finally is block which is followed by a Try block, an exception handling code section which gets executed whether an exception is raised or not by the try block. finalize() is a method of Object class which will be executed by the JVM just before garbage collecting object to give a final chance for resource releasing activity.

40. Can we declare a class as Abstract without having any abstract method?

Yes it is possible to create an abstract class just by using abstract keyword before class name even if it doesn't have any abstract method. However, a class must be declared as an abstract if it has one abstract method otherwise it will give an error.

41. What's the difference between an Abstract Class and Interface in Java?

The main difference between an interface and abstract class is that an interface only possess declaration of public static methods with no concrete implementation while an abstract class can have members with or without concrete implementation but with access specifiers (public, private etc). A class can only extend one abstract class as it has implemented multiple interfaces.

42. Is String a data type in java

In Java, String is not a primitive data type but it is actually an object of Java.Lang.String class that gets created. So, after creation of this string object, all built-in methods of String class can apply on the string object.

43. Why Strings in Java are called as Immutable?

In java, when a string object is declared and once value has been assigned to it, it can't be changed and if changed , a new object has been created. It is called immutable. So when a new value is assigned to it, a new string object gets created and the reference moved to the new object.

44. What is the constructor?

The special type of method or function which is used to initialize the state of an object is called constructor. When the class is instantiated, and the memory is allocated for the object, then the constructor is invoked.

45. How many types of constructors are used in Java?

There are two kinds of constructors. They are: i. Default Constructor: Default constructor is the one which does not accept any value. It is mainly used to initialize the instance variable with the default values. If there is no constructor defined in the class, then the default constructor is invoked implicitly by the compiler. ii. Parameterized Constructor: The constructor which can initialize the instance variables with the given values. Or, we can say that the constructors which can accept the values from the other functions are called parameterized constructors.

46. What is the function of a default constructor?

The function of the default constructor is to initialize the default value to the objects. If there is no constructor in the class, the java compiler implicitly creates a default constructor.

47. Does constructor return any value?

Yes, the constructor implicitly returns the current instance of the class (We can't use an explicit return type within the constructor)

48. When is a constructor called?

When an object is created using new() keyword then always one constructor is called. It calls a default constructor.

49. What are the rules for creating Java constructor?

There are three rules to create a constructor. 1. Constructor name must be the same as its class name 2. A Constructor must have no explicit return type 3. A Java constructor cannot be abstract, static, final, and synchronized

50. Difference between constructor and method in Java?

1. Java Constructor
a) Implicitly invoked
b) Name should be same as class.
c) Should not have return type.

2. Java Method
a) Explicitly invoked
b) Name should not be same as class
c) Must have return type

51. What is Exception in Java?

In Java, an event which disrupts the normal flow of the program is called an exception. It is an object which is thrown at runtime.

52. What is Exception Handling?

Exception Handling is an operations to handle runtime bugs such as IOException, SQLException, ClassNotFoundException, RemoteException, etc.

53. What is the advantage of Exception Handling in Java?

Exception handling has one core advantage that is to maintain the normal flow of the application. An exception normally disrupts the normal flow of the application hence we use exception handling.

54. What is Java Inner Classes?

Java inner class is a class which is declared within the class or interface. It is also called nested class.

55. What are the advantage of java inner classes?

There are mainly three advantages of inner classes. They are as mentioned:
1) Inner classes represent a special type of relationship that is it can access all the members of outer class including private.
2) Inner classes are used to develop more readable and maintainable code because it logically group all the classes and interfaces in one place only.
3) It requires less code to write.


56. What is a thread?

A thread is the smallest unit of processing which is a lightweight sub-process. To attain multitasking both multiprocessing and multithreading are used.

57. What is Multithreading?

In Java, Multithreading is a process of executing multiple threads simultaneously. Games, animation, etc. are created using java multithreading.

58. What are the Advantages of Java Multithreading?

i. It saves time so we can perform many operations together.
ii. It doesn't affect other threads if an exception occurs in a single thread as because threads are independent.
iii. User are not blocked because threads are independent.


59. What is Multitasking?

The process by which multiple tasks executes simultaneously is called multitasking. CPU provides multitasking concept.

60. By how many ways multitasking can be achieved?

Multitasking can be achieved in two ways:
i. Process-based Multitasking (Multiprocessing)
ii. Thread-based Multitasking (Multithreading)

61. What is AWT?

AWT (Abstract Window Toolkit) is an API to develop GUI or window-based applications.

62. Is AWT platform-dependent?

Yes, Java AWT components are platform-dependent because components are displayed according to the view of operating system

63. Which package provides classes for AWT api?

The java.awt package provides classes for AWT api such as TextField, Label, List, etc.

64. What is an API?

API is a set of functions and procedures that creates an applications and access the features or data of an operating system, application, or other service.

65. What is a Container?

In AWT, the Container is a component that can contain another components like buttons, textfields, labels etc.

66. What is a Panel?

The Panel is the container that contain components like button, textfield etc. but it doesn't contain title bar and menu bars.

67. What is a FRAME?

The Frame is the window container that contains both title bar and menu bars. And It also have other components like button, textfield etc.

68. Give an example of Java AWT?

import java.awt.*;
class First extends Frame{
First(){
Button bt = new Button("Tap me");
bt.setBounds(35,100,80,35);// setting button
position
add(bt);//adding button into frame
setSize(350,350);//frame size 300 width and 300
height
setLayout();//no layout manager
setVisible(true);//now frame will be visible, by
default not visible
}
public static void main(String args[]){
First fm = new First();
}
}


69. Can you have virtual functions in Java?

Yes, all functions in Java are virtual by default.

70. What is an abstraction?

Abstraction is a way of hiding the implementation details and shows all the functions to the user only. It displays just the important things to the user and hides all the internal information.

71. What is the difference between abstraction and encapsulation?

Abstraction is the process which hides all the implementation details whereas encapsulation wraps code and data into a single unit.

72. How to make a read-only class in Java?

A class can be made read-only when all the fields are made private. The read-only class will have only getter methods which return the private property of the class to the main method.

73. How to make a write-only class in Java?

A class can be made write-only when all the fields are made private which have only setter methods and set the value passed from the main method to the private fields.

74. How to create packages in Java?

If you are using the programming IDEs like Eclipse, NetBeans, etc. click on file->new->project and NetBeans will ask you to enter a name for the package. And finally select the path and click on the Finish button

75. Do I need to import java.lang package any time? Why?

No. By default JVM loaded it internally.

76. What is the output of the following Java program?

public class ExceptionHandlingExample {
public static void main(String args[]) {
try{
int a = 1/0;
System.out.println("a = "+a);
}
catch(Exception e){System.out.println(e);}
catch(ArithmeticException
ex){System.out.println(ex);
}}}
exception ArithmeticException has already been caught ^ 1 error

77. What is an applet?

An applet is a small size java program that runs within the browser and generates dynamic content. It is bind in the webpage and runs on the client side.

78. Write the architecture of an Applet?

Object -> Component -> Container -> Panel -> Applet -> JApplet

79. What is a JavaBean?

JavaBean is a software component which is reusable written in the Java programming language, designed to be manipulated visually by a software development environment.

80. How to perform Linear Search in Java?

import java.util.Scanner;
public class Linear_Search {
public static void main(String []args) throws
IOException {
int[] arr = {10, 23, 15, 8, 4, 3, 25, 30, 34, 2,
19};
int item,flag=0;
Scanner sc = new Scanner(System.in);
System.out.println("Enter the Item to be
searched?");
item = sc.nextInt();
for(int i = 0; i<10; i++) {
if(arr[i]==item){
flag = i+1;
break; }
else
flag = 0; }
if(flag != 0) {
System.out.println("Item found at location " +
flag); }
else
System.out.println("Item not found");
}
}
Output:
Enter the Item to be searched?
23
Item found at location 2
Enter the Item to be searched?
22
Item not found


81. How to perform Binary Search in Java?

import java.util.*;
public class Binary_Search {
public static void main(String []args) throws
IOException {
int[] arr = {16, 19, 20, 23, 45, 56, 78, 90, 96,
100};
int item, location = -1;
System.out.println("Enter the item which you want to
search");
Scanner sc = new Scanner(System.in);
item = sc.nextInt();
location = binarySearch(arr,0,9,item);
if(location != -1)
System.out.println("the location of the item is
"+location);
else
System.out.println("Item not found");
}
public static int Binary_Search(int[] a, int beg, int
end, int item)
{
int mid;
if(end >= beg)
{
mid = (beg + end)/2;
if(a[mid] == item)
{
return mid+1;
}
else if(a[mid] {
return Binary_Search(a,mid+1,end,item);
}
else
{
return BinarySearch(a,beg,mid-1,item);
}
}
return -1;
}
}
Output:
Enter the item which you want to search
45
the location of the item is 5


82. How to perform Quick sort in Java?

public class Quick_Sort {
public static void main(String[] args) {
int i;
int[] arr={91,24,101,5,65,12,67,79,34,14};
quickSort(arr, 0, 9);
System.out.println("\n The sorted array is: \n");
for(i=0;i<10;i++)
System.out.println(arr[i]);
}
public static int partition(int a[], int beg, int end)
{
int left, right, temp, loc, flag;
loc = left = beg;
right = end;
flag = 0;
while(flag != 1)
{
while((a[loc] <= a[right]) && (loc!=right))
right--;
if(loc==right)
flag =1;
elseif(a[loc]>a[right])
{
temp = a[loc];
a[loc] = a[right];
a[right] = temp;
loc = right;
}
if(flag!=1)
{
while((a[loc] >= a[left]) && (loc!=left))
left++;
if(loc==left)
flag =1;
elseif(a[loc] {
temp = a[loc];
a[loc] = a[left];
a[left] = temp;
loc = left;
}
}
}
returnloc;
}
static void quick_Sort(int a[], int beg, int end)
{
int loc;
if(beg {
loc = partition(a, beg, end);
quick_Sort(a, beg, loc-1);
quick_Sort(a, loc+1, end);
}
}
}
Output:
The sorted array is:
5
12
14
24
34
65
67
79
91
101


83. What is the difference between wait() and sleep() method?

wait( ) method is defined in the object class and it releases the lock whereas sleep() method is defined in the thread class and it does not releases the lock.

84. What is a servlet?

Java Servlet is a technologies of server-side which extends the capability of web servers by providing support for dynamic response and data persistence. The javax.servlet and javax.servlet.http packages provide interfaces and classes for writing our own servlets.

85. What are the differences between Get and Post methods?

Get
a) Limited amount of data is send
b) Data is sent in the header
c) Can be bookmarked
Post
a) Large amount of data is send.
b) Data is sent in the body
c) Cannot be bookmarked


86. What is Request Dispatcher?

RequestDispatcher is the interface which is used to forward the request to another resource that can be HTML, JSP or another servlet in same application.

87. What is life-cycle of a servlet?

A servlet has 5 stages in its lifecycle:
1. Servlet is loaded
2. Servlet is instantiated
3. Servlet is initialized
4. Service the request
5. Servlet is destroyed


88. How does cookies work in Servlets?

Cookies are the data in the form of sent to the client by server and it gets saved at the client local machine. Servlet API provides cookies which is supported by javax.servlet.http.Cookie class that implement both the interfaces, Serializable and Cloneable. Since there is no point of adding Cookie to request, there are no methods to set or add cookie to request, hence HttpServletRequest getCookies() method is provided to get the array of Cookies from request,. Similarly HttpServletResponse addCookie(Cookie c) method is provided to attach cookie in response header, there are no getter methods for cookie.

89. What are the different methods of session management in servlets?

Some of the common ways of session management in servlets are:
1. User Authentication
2. HTML Hidden Field
3. Cookies
4. URL Rewriting
5. Session Management API


90. What is JDBC Driver?

JDBC (Java DataBase Connectivity) Driver is a software component that allows java application to interact with the database. There are 4 types of JDBC drivers:
1. JDBC-ODBC bridge driver
2. Native-API driver (partially java driver)
3. Network Protocol driver (fully java driver)
4. Thin driver (fully java driver)


91. What are the steps to connect to a database in java?

1. Registering the driver class
2. Creating the connection
3. Creating the statement
4. Executing the queries
5. Closing the connection


92. What are the JDBC API components?

The java.sql package contains interfaces and classes for JDBC API.
Interfaces:
• Connection
• Statement
• PreparedStatement
• ResultSet
• ResultSetMetaData, etc.
Classes:
• DriverManager
• SQLException, etc.


93. What is the role of JDBC DriverManager class?

The DriverManager class manages all the registered drivers. It is used to register as well unregister drivers. It provides a method which acts as a factory that returns the instance of Connection.

94. What is the difference between execute, executeQuery, execute Update?

execute(String query) statement is used to execute any SQL query and if the result is an
ResultSet such as running Select queries then it returns TRUE otherwise it returns FALSE. We can use getResultSet() to get the ResultSet and getUpdateCount() method to retrieve the update count. executeQuery(String query) statement is used to execute Select queries and returns the ResultSet. ResultSet can never returned null even if there are no records matching the query. If someone tries to execute insert/update statement using executeQuery, then it will throw java.sql.SQLException with message “executeQuery method cannot be used for update”.
executeUpdate(String query) statement is used to execute Insert/Update/Delete (DML) statements or DDL statements that returns nothing. For SQL Data Manipulation Language (DML) statements the output is int and equals to the number of rows. For DDL statements, the output is 0.

95. What is Spring?

It a lightweight and integrated application framework and inversion of control container for the Java platform that can be used for developing enterprise applications

96. Name the different modules of the Spring framework.

Some of the important Spring Framework modules are:
• Spring Context :– for dependency injection.
• Spring AOP :– for aspect oriented programming.
• Spring DAO :– for database operations using DAO pattern
• Spring JDBC :– for JDBC and DataSource support.
• Spring ORM :– for ORM tools support such as Hibernate
• Spring Web Module :– for creating web applications.
• Spring MVC :– Model-View-Controller implementation for
creating web applications, web services etc.


97. List some of the important annotations in annotation-based Spring configuration.

The important annotations that are used in Spring configuration are as follows:
• @Required
• @Autowired
• @Qualifier
• @Resource
• @PostConstruct
• @PreDestroy


98. Explain Bean in Spring.

The objects that form the backbone of a Spring application is called the Bean. They are managed by the Spring IoC container. Alternatively, a bean is an object that is instantiated, assembled, and managed by a Spring IoC container.

99. What are some of the important Spring annotations which you have used?

Some of the Spring annotations that I have used in my project are:
@Controller – for controller classes in Spring MVC project.
@RequestMapping – for configuring URI mapping in controller handler methods.
@ResponseBody – for sending Object as response, usually for sending XML or JSON data as response.
@PathVariable – for mapping dynamic values from the URI to handler method arguments.
@Autowired – for autowiring dependencies in spring beans.
@Qualifier – with @Autowired annotation to avoid confusion when multiple instances of bean type is present.
@Service – for service classes.
@Scope – for configuring the scope of the spring bean.
@Configuration, @ComponentScan and @Bean – for java based configurations.
AspectJ annotations for configuring aspects and advices ,
@Aspect, @Before, @After, @Around, @Pointcut, etc.


100. What is the significance of packages?

In Java, packages helps to modularize all the codes and group the code so that it can be re-used properly. Once code has been packaged in Packages, it can be imported in other classes and used.

    JAVA FAQs




1. Is Acesoftech Academy an IT Company or a Training Institute?

Acesoftech Academy is a training institute which has been actively involved in ‘Class-room training’, ‘online training’ and ‘corporate training’

2. In what respect AcesoftechAcademy is different from other Java Training institutes in Kolkata?

The main difference between Acesoftech Academy and other Training centres is the quality of the training as well as the training procedure of the course. Fundamentally, if you compare our course content of Java to other training institutes then you will find that the modules/curriculum of all training centres of Java are almost same, but the core difference is in the teaching quality and methodology/implementation of the course. And this can be achieved only if the institute has quality trainers as well as dedicated trainers. It is the trainers who has key role to play in teaching. If the trainers are knowledgeable and qualified, training shall surely be good. Another problem is ‘trainers switching’ if trainer leaves the institute.Which is very common in this field? Normally trainers leave the job in-between and ultimately it’s the students who offer. We have our own dedicated andhighly qualified and experienced trainer.

3. Shall I work on live project during my Training?

Yes, in our Java training course, there are 3 projects involved, the projects are compulsory so that you get in-depth. Knowledge and also confidence.

4. Shall I receive Project and Training Certificate?

Yes, you will get training certificate after successful completion of the course. Apart from that we assign the group projects. If you complete that, you will get trainee certificate also from UNA WEBTECH, our sister IT Company of Acesoftech Academy

5. Is Java training available in the weekend also?

Yes, we are 7 days open. If you are college students or working professionals you can enrol for this course in the weekend also

6. Is there any provision of taking breaks during exams?

Yes, students are allowed to take break for exams. You need to show your exam date proof and we provide you break for exam preparation. Also, your course content will not be cut and you will be taught the full-course content.

7. What is the fee of training programs?

Basically, we have two types of Java Course, one is basic and another one is advanced. The course fee of the both courses you can know after contacting our academic counsellor.

8. Is there any facility of group discounts?

Yes, Acesoftech Academy provides group discounts also. The discount varies form number of students.

9. Can Course Fee be paid in Instalments?

Yes, instalments facility is also available. You can talk to our academic counsellor for that or you can send query through contact form as well as whatsApp.

10. What is the office timing of AcesoftechAcadedmy?

Our office-timing is from morning 10 am to evening 7 pm. And Sunday from 10 am to 2 pm.

11. What is the duration of classes?

In Week days (Monday to Friday) 2 hours 3 days in a week and in the week-end 3 hours 2 days in a week.

12. Is there any Job Assistance after Training?

Yes, we provide placement assistance also after successful completion of the course.

13. Does Acesoftech Academy provide summer training also?

Yes, we provide short-term summer training also

14. Shall I receive Project and Training Certificate?

Yes, Acesoftech Academy helps in college and university projects also.

15. How many students are there in a batch?

Batch strength differs from technology to technology. Minimum batch strength at Acesoftech Academy is 3 and maximum batch strength is ten.

16. Are programming assignments given to trainees during Training?

Yes, we assign project to the students which they have to submit. Depending upon the accuracy and complexity of the project, we provide grade also.

17. Can I give certification examination at Acesoftech Academy?

No, AcesoftechAcademy is not a prometric centre. We only deal in certification preparation.

18. My question is not listed in this FAQs section. How where to know the answer of more questions?

We have made contacting as easer as possible. You can ask the question through our enquiry form or WhatsApp.

    Features of Java




Why is Java so important today? What makes Java so popular? Why are the most developers using Java over other languages?, etc. There are many such questions which make Java so demanding now-a-days. So, are you excited to explore all these features of Java Programming Language? Let us begin!

List of features of Java programming languages-
1. Simple
2. Object-Oriented
3. Portable
4. Platform Independent
5. Secured
6. Robust
7. Architecture Neutral
8. Dynamic
9. High Performance
10. Multi-Threaded
11. Distributed
* Simple: The Java language is very easy to learn. Java coding is easy to read, understand and write.
* Object-Oriented programming language: Unlike C++ which is semi object-oriented and use the OS environment to execute, Java is a fully object-oriented programming language which has its own environment to run. It has all OOP features such as abstraction, encapsulation, inheritance and polymorphism.
* Portable: In Java, all source codes are converted into Java Byte code which can be carried out in any platform. Not an implementation dependent features. Everything is predefined related to storage, example: size of primitive data types
* Platform Independence: Java language is a platform independent language, that means it does not depend on the software environment. Java is guaranteed to be write-once, run-anywhere language. Java can run on multiple platforms as the program written is compiled first and then generated the bytecodes which is platform independent.
Java offers the feature “Write Once, Run Anywhere (WORA)”.
* Secure: Java is a secure programming language because of the following features:
• Java has no explicit pointer.
• Programs are run in a virtual machine sandbox.
• Java adds a class loader which separates the classes for a package of the local file system from imported ones from a network.
• It has a bytecode verifier which checks the code fragments for any illegal code that violate the access right.
• It as a security manager that defines the access for Java classes. All these features make java applications secured that can’t be invaded from outside even viruses cannot attacked Java applications.
* Robust:
Java is a strong (i.e. robust) language. Java lacks pointer so it helps applications to be more secured. It has exceptional handling and also type checking mechanism which makes Java a strong language. Java also maintain strong memory management system
* Architecture Neutral:
In Java, source codes are first compiled and then generate bytecodes. These bytecodes are platform independent which allows it to run on any computer architecture.
* Dynamic:
Java is a dynamic language because it can create links with all new Java class libraries, Java objects, and Java methods dynamically. It also allows the functions from its native languages such as C and C++.
* High Performance:
As Java is an interpreted language, so it will never be as fast as a compiled language like C or C++. But, JIT compiler enables high performance to Java applications. Java virtual machine (JVM) also executes Java applications at a very high speed.
* Multithreaded:
Java multithreading feature provides multi-tasking mechanism simultaneously. It utilizes same memory and other resources to execute multiple threads at the same time. We can build applications with many concurrent threads of activity, which results in highly interactive and responsive applications.
* Distributed Applications:
By using RMI and EJB features Java can create distributed applications. This feature of Java allows the user to invoke any file by calling any method on any computer.

    Future Scope and application of with Java




In Financial Services: All the major financial websites like HDFC Bank, ICIC Bank, SBI etc. are building using Java. In Big Data:HadoopMapReduce framework is written using Java.

Banking and Stock Exchange:
Stock market: To write algorithms as to which company they should invest in.
Railways: Billing applications that you usually see in a store/restaurant are mostly written in Java. Example: www.indianrailways.gov.in

Android: The popularAndroid Apps are either written in Java or use Java API.
Scientific and Research Community: To deal with huge amount of data.

    Job Roles and their average salaries




Some of the job roles available after learning Java are, Java Programmer- The average salary of a Java Programmer is INR 429,947 per year.
Java Developer- The average pay for a Java Developer is INR 434,304 per year. Senior Java Developer- The average pay of a Senior Java Developer is INR 650, 000 per year.

Web Developer- The average salary of a Web Developer is INR 2.75 to 3.5 lakhs per annum. J2EE / Java EE Developer- The average salary of a J2EE/ Java EE developer is INR 383,040 per annum.

Enterprise Application Developer and Architect- The average pay for an Enterprise Application Developer and Architect, IT is INR 2,248,345 per year.

Data Architect- The average salary of a Data Architect is INR 1,591,394 per year. Solution Architect- The average salary of a Solution Architect per year is INR 1,955 K. Enterprise Architect- The average pay for an Enterprise Architect, IT is Rs 2,248,345 per year.

Mobile Application Developer and Architect- The average salary for a Mobile Applications Developer and Architect is Rs 348,785 per year.

    Who can attendthe Java Training in Kolkata?




Our Java training in Kolkata is suitable for: Anyone who is interested in becoming Java developer College Students/School Students/Freshers Anyone who is seeing Job Software and application developers Programming enthusiasts Engineering graduates who wants to build career in Java Anyone who want to learn to develop Mobile Apps Anyone who want to learn software testing