[Gradle] Rename images and store them in js file

import java.security.MessageDigest;

buildscript {
	repositories {
		mavenCentral()
	}
}

task rename(type: Copy) {
    from 'in'
    into 'out'
    // Use a closure to map the file name
    rename { String fileName ->
        generateMD5(fileName)+fileExtension(fileName);
    }

}
task createList2() {
	File srcDir
	File list = new File("images.js")
	list.createNewFile()
	list.write("[")
	
	FilenameFilter fnf = {d, f-> f ==~ '\\.*'  } as FilenameFilter 
    // Create a file collection using a closure
    FileCollection collection = files { srcDir.listFiles([accept:{d, f-> f.indexOf(".") > 0 }] as FilenameFilter) }
    
    Collection c = []

    srcDir = file('in')
    println "Contents of $srcDir.name"
    collection.collect { it.name }.sort().each { c.add(it); }
    
    if(!c.isEmpty())
    {
    	Object last = c.pop();
    	c.each { list <<"{\"name\":\"" + it +"\"}," }
		list <<"{\"name\":\"" + last +"\"}"
	}
    list << "]"
}

task createList() {
	File srcDir
	File list = new File("out.js")
	list.createNewFile()
	list << "["
    // Create a file collection using a closure
    FileCollection collection = files { srcDir.listFiles() }
    
    Collection c = []

    srcDir = file('out')
    println "Contents of $srcDir.name"
    collection.collect { it.name }.sort().each { c.add(it); }
    Object last = c.pop();
    c.each { list <<"{\"name\":\"" + it +"\"}," }
	list <<"{\"name\":\"" + last +"\"}"
    list << "]"
}


 def generateMD5(String s) {
    MessageDigest digest = MessageDigest.getInstance("MD5")
    digest.update(s.bytes);
    new BigInteger(1, digest.digest()).toString(16).padLeft(32, '0')
 } 
 
 def fileExtension(String s) {
 s.substring(s.lastIndexOf("."));
 }