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Code Block

title	Java.from examples

var File = Java.type("java.io.File")
var listHomeDir = new File("~").listFiles()

// Java array to JavaScript array conversion by Java.from
var jsListHome = Java.from(listHomeDir)

var jpegModifiedDates = jsListHome
    .filter(function(val) { return val.getName().endsWith(".jpg") })
    .map(function(val) { return val.lastModified() })

Java.to function

Given a script object and a Java type, converts the script object into the desired Java type. Currently it performs shallow creation of Java arrays, as well as wrapping of objects in Lists and Dequeues. Example:

Code Block

title	Java.to example

var anArray = [1, "13", false]

// Java.to used to convert script array to a Java int array
var javaIntArray = Java.to(anArray, "int[]")

print(javaIntArray[0])  // prints 1
print(javaIntArray[1])  // prints 13, as string "13" was converted to number 13 
                        // as per ECMAScript ToNumber conversion
print(javaIntArray[2])  // prints 0, as boolean false was converted to number 0
                        // as per ECMAScript ToNumber conversion

Java._super function

When given an object created using Java.extend() or equivalent mechanism (that is, any JavaScript-to-Java adapter), returns an object that can be used to invoke superclass methods on that object. E.g.:

Code Block

title	Java.super example

var CharArray = Java.type("char[]")
var jString = Java.type("java.lang.String")
var Character = Java.type("java.lang.Character")

function capitalize(s) {
    if(s instanceof CharArray) {
        return new jString(s).toUpperCase()
    }
    if(s instanceof jString) {
        return s.toUpperCase()
    }
    return Character.toUpperCase(s) // must be int
}

var sw = new (Java.type("java.io.StringWriter"))

var FilterWriterAdapter = Java.extend(Java.type("java.io.FilterWriter"))

var cw = new FilterWriterAdapter(sw) {
    write: function(s, off, len) {
        s = capitalize(s)
        // Must handle overloads by arity
        if(off === undefined) {
            cw_super.write(s, 0, s.length())
        } else if (typeof s === "string") {
            cw_super.write(s, off, len)
        }
    }
}
var cw_super = Java.super(cw)

cw.write("abcd")
cw.write("e".charAt(0))
cw.write("fgh".toCharArray())
cw.write("**ijk**", 2, 3)
cw.write("***lmno**".toCharArray(), 3, 4)
cw.flush()
print(sw)

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Old Version 9

New Version 10

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