Why use classpath

So tell me Why is required?? September 26, at AM Augusto said December 13, at AM Myle said Thanks in advance March 31, at AM Manju said April 30, at AM Unknown said November 27, at PM Anonymous said I like your posts March 18, at PM student said April 30, at AM Anonymous said July 7, at AM Vikas Prasad said Awesome article.

January 30, at PM javin paul said February 6, at AM Unknown said February 23, at AM Anonymous said August 2, at PM Unknown said August 5, at PM javin paul said August 5, at PM Vikram S said December 1, at PM Anonymous said Newer Post Older Post Home. Subscribe to: Post Comments Atom. Subscribe for Discounts and Updates Follow. Search This Blog. Interview Questions core java interview question data structure and algorithm 78 Coding Interview Question 75 interview questions 70 design patterns 35 SQL Interview Questions 34 object oriented programming 34 thread interview questions 30 spring interview questions 28 collections interview questions 25 database interview questions 16 servlet interview questions 15 Programming interview question 6 hibernate interview questions 6.

How to design a vending machine in Java? How HashMap works in Java? Why String is Immutable in Java? Translate This Blog.

How to Solve java. ClassNotFoundException: org How to use var to declare local variables in Java? Example What is SuppressWarnings annotation in Java? Difference between Process and Thread in Java - Ex Spring Transactional Annotation Example - How to How to create thread safe Singleton in Java - Java How to Code in Dart Programing language?

Dart Hell Inner class and nested Static Class in Java with E How to append text into File in Java — FileWriter Top 5 Courses to learn Unreal Engine in - Bes How to add, subtract days, months, years, hours fr What is final in Java?

Final variable , Method and What is Type Casting in Java? Casting one Class to How to use Lombok Library in Java? Observer design Pattern in Java with Real world co How to get current date, month, year and day of we How to convert milliseconds to Date in Java - Tuto How to check if a number is a palindrome or not in How to check if String contains another SubString Difference between mvn install, release and deploy How to check if a String is numeric in Java?

Use i How to remove duplicates elements from ArrayList i How to read input from command line in Java using Top 3 Free and Best Svelte. What is Constructor in Java with Example — Constru How to sort HashMap by key and value in Java - Has How to comment uncomment single line and block of Top 10 Coursera Certifications, Courses, and Speci How to split String in Java by WhiteSpace or tabs?

How to Check if two Rectangles Overlap in Java? Top 5 Computer Vision Certifications and Courses f How to do static import in Eclipse - Java Example When to make a method final in Java? Before we talk about how the classpath is set, let's talk about. First, let's suppose that MyClass is something you built as part of your project, and it is in a directory in your project called output.

In order to get to that file, your path would simply need to contain the folder 'output', not the whole package structure, since your import statement provides all that information to the VM. Now let's suppose that you bundle CoolFramework up into a. The first way everyone seems to learn is with environment variables.

On a unix machine, you can say something like:. On a Windows machine you have to go to your environment settings and either add or modify the value that is already there. A variant of this is the third way which is often done with a. There is a "gotcha" with all of the above. In windowsm the separator is the semicolon ';'. Setting stuff globally via environment variables is bad, generally for the same kinds of reasons that global variables are bad.

The -cp is the way to go. I generally make sure my CLASSPATH environment variable is an empty string where I develop, whenever possible, so that I avoid global classpath issues some tools aren't happy when the global classpath is empty though - I know of two common, mega-thousand dollar licensed J2EE and Java servers that have this kind of issue with their command-line tools. The classpath is the path where the Java Virtual Machine look for user-defined classes, packages and resources in Java programs.

The classpath in this context is exactly what it is in the general context: anywhere the VM knows it can find classes to be loaded, and resources as well such as output. I'd understand Velocity expects to find a file named output. This can be a JAR, regular folder, The root of any of the locations in the application's classpath. The classpath is one of the fundamental concepts in the Java world and it's often misunderstood or not understood at all by java programmes, especially beginners.

Simply put, the classpath is just a set of paths where the java compiler and the JVM must find needed classes to compile or execute other classes. Let's start with an example, suppose we have a Main. I'll explain why, first of all, the name of the class that we want ro tun is org. Main not Main , or Main. This is how things works with classes declared under packages. Thats where the classpath comes into picture.

Using -cp flag shortcut for -classpath , we tell the JVM that our Main. In fact, not really, we tell it to just go to the Desktop directory, and, because of the name of the class org. Main, the JVM is smart and it will go from Desktop to org directory, and from org to example directory, searching for Main. Now lets suppose that inside the Main class we want to work with another class named org. Include all the directories which contain. It means the only current directory searched.

Put a dot. The classes can be stored in directories or archives files. The classes of the Java platform are stored in rt. In the above command, The set is an internal DOS command that allows the user to change the variable value. The semicolon is a separator, and after the ; there is the PATH of rt.

The classes which are available within JARs in the ext directory are available to Java applications. The mechanism will pick up all. The implementation of this is that if one can change the name of a jar placed in a classpath directory to have an extension other than. This technique will not work with the extension directory. Compile the A. Place this JAR file into another directory than the compiled B.

To demonstrate the use of the classpath, we place the A. We found that B can still load the A. It is useful to set the PATH environment variable permanently so it will persist after rebooting. The precise procedure varies depending on the version of Windows:.

However, you should set the path variable if you want to be able to run the executables javac , java , javadoc , and so on from any directory without having to type the full path of the command. This will print the version of the java tool, if it can find it. If the version is old or you get the error java: Command not found , then the path is not properly set.

For ksh , the startup file is named by the environment variable, ENV.