JPad Functions

JPad provides a class specifically to make life easier for JPad users. See javadoc for function specifications. The JPad class allows:

Running Terminal Or Console Commands
Writing to CSV Files
Caching results to prevent repeating work
Accepting User Input / Command Line Arguments

Running Terminal Or Console Commands

Running a command, capturing it's output and reporting back the result as a string can be achieved using the cmd function:

// JPad.cmd runs commands as if entered at the command line.

// Run command line in array format
// useful to reduce need for escaping quotes etc.
Dump(JPad.cmd(new String[] { "echo","hello world!"} ));


// Run command -  String format as you would write at terminal
Dump(JPad.cmd("java -version"));

Console Output

hello world!

java version "1.8.0_31"
Java(TM) SE Runtime Environment (build 1.8.0_31-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.31-b07, mixed mode)

Writing Objects to CSV Files

The JPad.writeCsv function writes objects to CSV using the JPad object to table converter.

final File file = new File("c:\\temp\\outt.csv");
Object o = new int[] {1,2,3};

JPad.writeCsv(o, file);

// read file back to check what was written
Dump(Files.readAllLines(file.toPath()));

Console Output

[int[], 1, 2, 3]

Caching results to prevent repeating work

Jpad.cache can be used to prevent repeating expensive calls on each run The callable only gets ran if a cache entry does not already exist.

// Uncomment either one of these lines and it forces the calculation to be done each time.
//JPad.cacheClear("b");
//JPad.cacheClearAll();

Callable<Integer> c = () -> {	
	Dump("calcing"); 
	return 22; 
	};

// By using Cache callable, the function only gets called to generate the value once.
// The remainder of the time, it is retrieved from cache.
Integer b = JPad.cache("b", Integer.class, c);
b = JPad.cache("b", Integer.class, c);
b = JPad.cache("b", Integer.class, c);
b = JPad.cache("b", Integer.class, c);
Dump("b = " + b);

Accepting User Input / Command Line Arguments

int num = JPad.getArg(args, 0, "number", 300);
Dump("num x 2: " + (num*2));

JPad profiles functions to allow easy script input in multiple forms:

Command Line Arguments
Terminal Text Entry
GUI Dialog Entry

It does this using the JPad.getArg(args, idx, title, defaultValue) function. The arguments are:

args - String[] array holding command line arguments.
idx - index position into arguments.
title - title of value that is wanted..
defaultValue - default value shown to user and assumed if user enters nothing.

This means whether the user wants to run it interactively in the GUI or terminal that it will always work. Like so

Interactive Terminal

C:>jpad getArg.jpad
Please enter number:[300]
22
num x 2: 44

Interactive GUI

Command Line

C:>jpad getArg.jpad -args 22
num x 2: 44

JPad Functions

Running Terminal Or Console Commands

Console Output

Writing Objects to CSV Files

Console Output

Caching results to prevent repeating work

Accepting User Input / Command Line Arguments

Interactive Terminal

Interactive GUI

Command Line

See Also