FileUtils.groovy

import java.nio.*

/**
 * Fast copy with java.nio.channels
 *  
 * Usage:
 *  
 *  FileUtils.fastCopy(new File("from.bin"), new File("to.bin"))
 * 
 * @author Marcel Maatkamp (m.maatkamp avec gmail dot com)
 */
class FileUtils { 

  static fastCopy(from, to) { 
    def ic=null, oc=null

    assert from.canRead()
    assert to.canWrite()

    try { 
      if(!to.exists()) { 
        to.createNewFile()
      }

      ic = new FileInputStream(from).channel
      oc = new FileOutputStream(to).channel
      oc.transferFrom(ic, 0, ic.size())

    } finally {
      if(ic) ic.close()
      if(oc) oc.close()
    }
  }
}