Translating Java to Scala

Java code to translate

   public byte[] getBytes(String path) throws IOException,
   ClassNotFoundException {
       System.out.println("reading: " + path);
       File f = new File(classpath + (classpath.length()==0?"":File.separator)
               + path.replace('.', File.separatorChar) + ".class");
       int length = (int) (f.length());
       if (length == 0) {
           System.out.println("File length is zero");
           throw new IOException("File length is zero: " + path);
       } else {
           byte[] bytecodes;
           FileInputStream fin = null;
           DataInputStream in = null;
           try {
               fin = new FileInputStream(f);
               in = new DataInputStream(fin);

               bytecodes = new byte[length];
               in.readFully(bytecodes);
           } finally {
               try {
                   in.close();
               } catch (IOException e) {
                   // We tried - keep going - the bytecodes may still be ok
               }
               try {
                   fin.close();
               } catch (IOException e) {
                   // We tried - keep going - the bytecodes may still be ok
               }
           }
           return bytecodes;
       }
   }

First attempt

 def getBytes(path: String) : Array[Byte] = {
   println("reading: " + path);
   val f = new File(classpath + (if (classpath.length()==0) "" else File.separator)  + path.replace('.', File.separatorChar) + ".class");
   val length:Int = f.length().asInstanceOf[Int];
   if (length == 0) {
     println("File length is zero");
     throw new IOException("File length is zero: " + path);
   } else {
     var fin: FileInputStream = null
     var in: DataInputStream = null
     var bytecodes:Array[Byte] = null
     try {
       fin = new FileInputStream(f);
       in = new DataInputStream(fin);
       bytecodes = new Array[Byte](length);
       in.readFully(bytecodes);
     } finally {
       try { in.close(); } catch { case _ => }
       try { fin.close(); } catch { case _ => }
     }

     return bytecodes;
   }
 }

Much nicer using resource management

 def getBytes(path: String) : Array[Byte] = {
   println("reading: " + path);
   val f = new File(classpath + (if (classpath.length()==0) "" else File.separator)  + path.replace('.', File.separatorChar) + ".class");
   val length:Int = f.length().asInstanceOf[Int];
   if (length == 0) {
     println("File length is zero");
     throw new IOException("File length is zero: " + path);
   } else {
     val bytecodes = new Array[Byte](length);
     withDataInputStream(f) { dis =>
       dis.readFully(bytecodes);
     }
     return bytecodes;
   }
 }

 def withDataInputStream(f: File)(operation: DataInputStream => Unit) {
   val fin = new FileInputStream(f)
   val in = new DataInputStream(fin);
   try {
     operation(in)
   } finally {
     try { in.close(); } catch { case _ => }
     try { fin.close(); } catch { case _ => }
   }
 }