code: def emit_java_headers(target, source, env):
      class_suffix = env.get('JAVACLASSSUFFIX', '.class')
      classdir = env.get('JAVACLASSDIR')
      if not classdir:
          try:
              s = source[0]
          except IndexError:
              classdir = '.'
          else:
              try:
                  classdir = s.attributes.java_classdir
              except AttributeError:
                  classdir = '.'
      classdir = env.Dir(classdir).rdir()
      if str(classdir) == '.':
          c_ = None
      else:
          c_ = str(classdir) + os.sep
      slist = []
      for src in source:
          try:
              classname = src.attributes.java_classname
          except AttributeError:
              classname = str(src)
              if c_ and classname[:len(c_)] == c_:
                  classname = classname[len(c_):]
              if class_suffix and classname[-len(class_suffix):] == class_suffix:
                  classname = classname[:-len(class_suffix)]
              classname = SCons.Tool.javac.classname(classname)
          s = src.rfile()
          s.attributes.java_classname = classname
          slist.append(s)
      s = source[0].rfile()
      if not hasattr(s.attributes, 'java_classdir'):
          s.attributes.java_classdir = classdir
      if target[0].__class__ is SCons.Node.FS.File:
          tlist = target
      else:
          if not isinstance(target[0], SCons.Node.FS.Dir):
              target[0].__class__ = SCons.Node.FS.Dir
              target[0]._morph()
          tlist = []
          for s in source:
              fname = s.attributes.java_classname.replace('.', '_') + '.h'
              t = target[0].File(fname)
              t.attributes.java_lookupdir = target[0]
              tlist.append(t)
      return tlist, source