M9PSv.png' alt='Java Verify Zip File' title='Java Verify Zip File' />Java Interview Questions tutorialspoint. Dear readers, these Java Interview Questions have been designed especially to get you acquainted with the nature of questions you may encounter during your interview for the subject of Java Programming Language. As per my experience, good interviewers hardly planned to ask any particular question during your interview, normally questions start with some basic concept of the subject and later they continue based on further discussion and what you answer What do you know about Java Java is a high level programming language originally developed by Sun Microsystems and released in 1. Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX. Java Verify Zip File' title='Java Verify Zip File' />What are the supported platforms by Java Programming Language Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIXLinux like HP Unix, Sun Solaris, Redhat Linux, Ubuntu, Cent. Java Verify Zip File' title='Java Verify Zip File' />OS, etc. List any five features of Java Some features include Object Oriented, Platform Independent, Robust, Interpreted, Multi threaded Why is Java Architectural Neutral Its 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. How Java enabled High PerformanceI have a JAR file and I need to get the name of all classes inside this JAR file. How can I do that I googled it and saw something about JarFile or Java ClassLoader. Collection of machine learning algorithms for solving data mining problems implemented in Java and open sourced under the GPL. Features documentation and related. This documentation can be obtained by invoking TestNG without any arguments. You can also put the command line switches in a text file, say ccommand. Java Verify Zip File' title='Java Verify Zip File' />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. Why Java is considered dynamic 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. What is Java Virtual Machine and how it is considered in context of Javas platform independent feature When Java is compiled, it is not compiled into platform specific machine, rather into platform independent byte code. This byte code is distributed over the web and interpreted by virtual Machine JVM on whichever platform it is being run. List two Java IDEs Netbeans, Eclipse, etc. List some Java keywordsunlike C, C keywords Some Java keywords are import, super, finally, etc. What do you mean by ObjectObject is a runtime entity and its state is stored in fields and behavior is shown via methods. Methods operate on an objects internal state and serve as the primary mechanism for object to object communication. Define class 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. What kind of variables a class can consist of A class consist of Local variable, instance variables and class variables. What is a Local Variable 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. What is a Instance Variable Instance variables are variables within a class but outside any method. These variables are instantiated when the class is loaded. What is a Class VariableThese are variables declared with in a class, outside any method, with the static keyword. What is Singleton class Singleton class control object creation, limiting the number to one but allowing the flexibility to create more objects if the situation changes. What do you mean by Constructor 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. List the three steps for creating an Object for a class An Object is first declared, then instantiated and then it is initialized. What is the default value of byte datatype in Java Default value of byte datatype is 0. What is the default value of float and double datatype in Java Default value of float and double datatype in different as compared to CC. For float its 0. 0f and for double its 0. When a byte datatype is used 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. What is a static variable Class variables also known as static variables are declared with the static keyword in a class, but outside a method, constructor or a block. What do you mean by Access Modifier 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. What is protected access modifierVariables, 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. Movie Websites To Download Free Movies. What do you mean by synchronized Non Access Modifier Java provides these modifiers for providing functionalities other than Access Modifiers, synchronized used to indicate that a method can be accessed by only one thread at a time. According to Java Operator precedence, which operator is considered to be with highest precedence Postfix operators i. Variables used in a switch statement can be used with which datatypes Variables used in a switch statement can only be a string, enum, byte, short, int, or char. When parse. Int method can be used This method is used to get the primitive data type of a certain String. Why is String class considered immutableThe String class is immutable, so that once it is created a String object cannot be changed. Since String is immutable it can safely be shared between many threads ,which is considered very important for multithreaded programming. Why is String. Buffer called mutable 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 String. Buffer should be used. What is the difference between String. Buffer and String. Builder class Use String. Builder whenever possible because it is faster than String. Buffer. But, if thread safety is necessary then use String. Buffer objects. Which package is used for pattern matching with regular expressions Pattern class, Matcher class and Pattern. Syntax. Exception class. What is finalize methodIt is possible to define a method that will be called just before an objects final destruction by the garbage collector. This method is called finalize, and it can be used to ensure that an object terminates cleanly. What is an Exception An exception is a problem that arises during the execution of a program. Exceptions are caught by handlers positioned along the threads method invocation stack. What do you mean by Checked Exceptions It is an exception that is typically a user error or a problem that cannot be foreseen by the programmer. For example, if a file is to be opened, but the file cannot be found, an exception occurs. These exceptions cannot simply be ignored at the time of compilation. Explain Runtime Exceptions It is an exception that occurs that probably could have been avoided by the programmer. As opposed to checked exceptions, runtime exceptions are ignored at the time of compliation. Which are the two subclasses under Exception class The Exception class has two main subclasses IOException class and Runtime.