How can I have a command line prompt call a method in Java?

You can't directly call methods from the command line, since the code is compiled. If it was a language that is only interpreted, such as Python, you would be able to do that by simply typing the name of the method with it's arguments. What you can do is use something such as a java.io.BufferedReader or java.util.Scanner and such to read what the user types into the command line and interpret it. For example: Scanner s = new Scanner(System.in); String line = s.readLine(); if(line.startsWith("myMethod")){ java.util.StringTokenizer st = new java.util.StringTokenizer(line.substring… line.length() - 1), ",", false); String arg0 = st.nextToken(); String arg1 = st.nextToken(); String arg2 = st.nextToken(); myMethod(arg0, arg1, arg2); } What I did: I created a Scanner object, read one line from the command line (System.in). If that line starts with "myMethod", then we assume the user wants to call the method myMethod, which takes 3 arguments.Then we substring the line to get everything in between the parenthesys and make a StringTokenizer with it. Then we separate the tokens by ",", then supply the tokens to the method. Of course, you should handle cases where, for example, the user types too many or too few arguments. Also handle other argument types, like integers, with Integer.parseInt(). EDIT--- If you mean calling the method while the program is NOT running, do the following, assuming you method's name is myMethod() and it takes two arguments. public class MyClass{ public static void main(String[] args){ myMethod(args[0], args[1]); } public static void myMethod(String arg0, String arg1){ //do your stuff here } } Compile it: >javac MyClass.java Then type the following at the command line: >java MyClass

Not enough information, really. If the method is static, and in another class, then use: OtherClass.printItOut(...args...); ...and maybe assign the result. If the method is static and defined in the same class, then you don't need the classname. part: printItOut(..args...); If it is not static, then it's an instance method and you'll have to create an instance of that class and then use that instance to invoke the method: OtherClass anObject = new OtherClass(); anObject.printItOut(..args...); In this case, you probably also have arguments to the constructor, or other method calls, to supply the anObject instance with what to print and/or where to print it.

import java.util.Properties main() { try { Process P=Runtime.getRuntime().exec("C:\\windows… } catch(IOException E){} } The above will start notepad. Here, we assume notedpad.exe is available in C:\windows directory If you want to run your program, insert its exe file name along with path informatio and argument. Read about processbuilder class and use if needed

Not quite sure what you're asking but You can run the .class that contains the main(..) method file from the command line with dir>java myClass