Running Java program from the command prompt

Source: http://www.tutorialspoint.com/junit/junit_environment_setup.htm

Step 1 - verify Java installation in your machine

Now open console and execute the following java command.

OS	Task	Command
Windows	Open Command Console	c:\> java -version
Linux	Open Command Terminal	$ java -version
Mac	Open Terminal	machine:~ joseph$ java -version

Let's verify the output for all the operating systems:

OS	Output
Windows	java version "1.6.0_21" Java(TM) SE Runtime Environment (build 1.6.0_21-b07) Java HotSpot(TM) Client VM (build 17.0-b17, mixed mode, sharing)
Linux	java version "1.6.0_21" Java(TM) SE Runtime Environment (build 1.6.0_21-b07) Java HotSpot(TM) Client VM (build 17.0-b17, mixed mode, sharing)
Mac	java version "1.6.0_21" Java(TM) SE Runtime Environment (build 1.6.0_21-b07) Java HotSpot(TM)64-Bit Server VM (build 17.0-b17, mixed mode, sharing)

If you do not have Java installed, install the Java Software Development Kit (SDK) fromhttp://www.oracle.com/technetwork/java/javase/downloads/index.html. We are assuming Java 1.6.0_21 as installed version for this tutorial.

Step 2: Set JAVA environment

Set the JAVA_HOME environment variable to point to the base directory location where Java is installed on your machine. For example

OS	Output
Windows	Set the environment variable JAVA_HOME to C:\Program Files\Java\jdk1.6.0_21
Linux	export JAVA_HOME=/usr/local/java-current
Mac	export JAVA_HOME=/Library/Java/Home

Append Java compiler location to System Path.

OS	Output
Windows	Append the string ;C:\Program Files\Java\jdk1.6.0_21\bin to the end of the system variable, Path.
Linux	export PATH=$PATH:$JAVA_HOME/bin/
Mac	not required

Verify Java Installation using java -version command explained above.

Step 3: Download Junit archive

Download latest version of JUnit jar file from http://www.junit.org. At the time of writing this tutorial, I downloaded Junit-4.10.jar and copied it into C:\>JUnit folder.

OS	Archive name
Windows	junit4.10.jar
Linux	junit4.10.jar
Mac	junit4.10.jar

Step 4: Set JUnit environment

Set the JUNIT_HOME environment variable to point to the base directory location where JUNIT jar is stored on your machine. Assuming, we've stored junit4.10.jar in JUNIT folder on various Operating Systems as follows.

OS	Output
Windows	Set the environment variable JUNIT_HOME to C:\JUNIT
Linux	export JUNIT_HOME=/usr/local/JUNIT
Mac	export JUNIT_HOME=/Library/JUNIT

Step 5: Set CLASSPATH variable

Set the CLASSPATH environment variable to point to the JUNIT jar location. Assuming, we've stored junit4.10.jar in JUNIT folder on various Operating Systems as follows.

OS	Output
Windows	Set the environment variable CLASSPATH to %CLASSPATH%;%JUNIT_HOME%\junit4.10.jar;.;
Linux	export CLASSPATH=$CLASSPATH:$JUNIT_HOME/junit4.10.jar:.
Mac	export CLASSPATH=$CLASSPATH:$JUNIT_HOME/junit4.10.jar:.

Step 6: Test JUnit Setup

Create a java class file name TestJunit in C:\ > JUNIT_WORKSPACE

   
import org.junit.Test;
import static org.junit.Assert.assertEquals;
public class TestJunit {
   @Test
   public void testAdd() {
      String str= "Junit is working fine";
      assertEquals("Junit is working fine",str);
   }
}

Create a java class file name TestRunner in C:\ > JUNIT_WORKSPACE to execute Test case(s)

import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;

public class TestRunner {
   public static void main(String[] args) {
      Result result = JUnitCore.runClasses(TestJunit.class);
      for (Failure failure : result.getFailures()) {
         System.out.println(failure.toString());
      }
      System.out.println(result.wasSuccessful());
   }
}   

Step 7: Verify the Result

Compile the classes using javac compiler as follows

C:\JUNIT_WORKSPACE>javac TestJunit.java TestRunner.java

Now run the Test Runner to see the result

C:\JUNIT_WORKSPACE>java TestRunner

Verify the output.

true

Practical:
- Write a java program in a notepad
- Save it with same name as that of its class name
- Open the command prompt, set path and class path

path:
set path = "c:\java 1.5\bin"

C:\ YourFolder >javac YourCode.java

Note: If you set the class path you can execute java code from anywhere.

set classpath = c:\java\jre\lib; %classpath%


Execute java program on your local machine without SDK:

Syntax:
- Set path="JDK path" //set up jdk path:
- javac "path/filename.java" //compile java file by giving full path of the file
- java "path/filename" //execute the file by giving full path of the file


Validation:
java -version // this will check your jre version
javac -version // this will check your java compiler version if you installed