Learning Rhino 2

Hello Rhino
First, look at my examples' file structure:

RhinoTest
	lib
		js.jar
	scripts
		hello.js
		file1.js
	run.bat

My first rhino example is hello.js:

for (var i = 0; i < arguments.length; i++) {
    print('arguments[' + i + '] = ' + arguments[i]);
}

function add() {
    var result = 0;
    for (var i = 0; i < arguments.length; i++) {
        result += arguments[i];
    }
    return result;
}
print('2 + 5 + 3 = ' + add(2, 5, 3));

The hello.js is executed through batch file run.bat:

@echo off

echo.
echo ---------- hello ----------
java -cp libjs.jar org.mozilla.javascript.tools.shell.Main scriptshello.js Hello Rhino

And the result:

arguments[0] = Hello
arguments[1] = Rhino
2 + 5 + 3 = 10

How to get user’s current working directory
We all know java.lang.System class contains several useful fields and methods.
The getProperties method can be used to determine the current system properties.

var System = Packages.java.lang.System;

print('Working directory = ' + System.getProperty('user.dir'));
print('Home directory = ' + System.getProperty('user.home'));
print('Account name = ' + System.getProperty('user.name'));
print('Line separator ("\n" on UNIX) = ' + (String(System.getProperty('line.separator')) === 'rn' ? '\r\n' : '\n'));
print('File separator ("/" on UNIX) = ' + System.getProperty('file.separator'));

Output:

Working directory = D:documentsRhinoTest
Home directory = C:Documents and Settingssanshi
Account name = sanshi
Line separator ("n" on UNIX) = rn
File separator ("/" on UNIX) = 

File or Path exist

var System = Packages.java.lang.System;
var File = Packages.java.io.File;
var userDir = System.getProperty('user.dir');

var file = new File(userDir + "\scripts\hello.js");
print(file.exists());   /* true */
print(new File(userDir + "\scripts").exists());   /* true */

Read File to string
Use LineNumberReader to read file to string:

var System = Packages.java.lang.System;
var File = Packages.java.io.File;
var lineSeparator = System.getProperty('line.separator');
var userDir = System.getProperty('user.dir');

var reader = new Packages.java.io.LineNumberReader(
    new Packages.java.io.FileReader(userDir + "\scripts\hello.js"));
var lines = [];
while (line = reader.readLine()) {
    lines.push(line);
    lines.push(lineSeparator);
}
reader.close();
print(lines.join(''));

Write string to file
Refer to BufferedWriter

var System = Packages.java.lang.System;
var userDir = System.getProperty('user.dir');

var writer = new Packages.java.io.PrintWriter(
    new Packages.java.io.BufferedWriter(
	    new Packages.java.io.FileWriter(userDir + "\scripts\output.txt")));
writer.write("This is file content.rnIt's easy!");
writer.flush();
writer.close();

Refer to JsDoc Toolkit