; showing class and object operations using a StringBuffer.

.class public StringBufferDemo
.super java/lang/Object

.method public <init>()V
  aload_0
  invokespecial java/lang/Object/<init>()V
  return
.end method

.method private static sbDemo(Ljava/lang/Object;)V
  .limit stack 2
  .limit locals 2
  ; local 0 contains the sb, cast it from 
  ; java.lang.Object to java.lang.StringBuffer

  aload_0
  ; this cast is required
  checkcast java/lang/StringBuffer
  ldc "Hello, mundo!"
  ; append string to sb
  invokevirtual java/lang/StringBuffer/append(Ljava/lang/String;)Ljava/lang/StringBuffer;
  return
.end method

.method public static main([Ljava/lang/String;)V
  .limit stack 3
  .limit locals 2

  ; create a new StringBuffer
  new java/lang/StringBuffer
  dup
  invokespecial java/lang/StringBuffer/<init>()V
  astore_1 ; sb is now in local 1

  ; initialise sb with value
  aload_1
  ;checkcast java/lang/Object
  ; auto-cast to Object
  invokestatic StringBufferDemo/sbDemo(Ljava/lang/Object;)V

  ; print the contents of the initialised sb
  getstatic java/lang/System/out Ljava/io/PrintStream;
  aload_1
  invokevirtual java/lang/StringBuffer/toString()Ljava/lang/String;
  invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V
  return
.end method