If you are using or higher, then you can simply execute java JavaHelloWorldProgram.java and it will compile and execute the program for you. No need to explicitly compile and then run the java program. Java Hello World Program important points. Any java source file can have multiple classes but they can have only one public class.
Hello World Example in Java. System.out.println is used print statement. As displayed in the above diagram, write the MyFirstJavaProgram program of java in notepad and saved it as MyFirstJavaProgram.java. To compile and run this program, you need to open command prompt by Start - All Programs - Accessories - command prompt.
The java source file name should be same as public class name. That’s why the file name we saved our program was JavaHelloWorldProgram.java. When we compile the code, it generates byte code and save it as ClassName.class extension. If you look at the directory where we compiled the java file, you will notice a new file created JavaHelloWorldProgram.class. When we execute the class file, we don’t need to provide full file name. We need to use only the public class name. When we run the program using java command, it loads the class into and looks for the in the class and runs it.
The main function syntax should be same as specified in the program, else it won’t run and throw exception as Exception in thread 'main' java.lang.NoSuchMethodError: main.I have recently created a short video for Java Hello World Program using Notepad and then Eclipse. Watch it for better understanding.
![Java Hello World Java Hello World](/uploads/1/2/5/5/125507944/894378934.png)
Example.java.helloworldThis is 'Hello World' Example for Java.The structure HelloWorld package is like this: example.java.helloworld/ - HelloWorld `- Main.java - LICENSE - Manifest.txt`- README.mdCompile classFor compile the main class for package, execute the follow command: javac HelloWorld/Main.javaThis generate the Main.class file into HelloWorld directory. Run classFor run the main class for package, execute the follow command: java -cp. HelloWorld.MainThis show the Hello world message. Create a JAR fileFor pack the main class for package as a JAR file, execute the follow command: jar cfme Main.jar Manifest.txt HelloWorld.Main HelloWorld/Main.classRun a JAR fileFor run the JAR file packed, execute the follow command: java -jar Main.jarThis show the Hello world message.