diff --git a/.gitignore b/.gitignore
index 0422adf44..26dbde73d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 *.pyc
 *.pyo
+*.class
 *~
 *.DS_Store
 wine-py2exe/
@@ -32,4 +33,4 @@ test/testdata
 .tox
 youtube-dl.zsh
 .idea
-.idea/*
\ No newline at end of file
+.idea/*
diff --git a/Makefile b/Makefile
index cb449b7e6..afd7f4032 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,7 @@ all: youtube-dl README.md CONTRIBUTING.md README.txt youtube-dl.1 youtube-dl.bas
 clean:
 	rm -rf youtube-dl.1.temp.md youtube-dl.1 youtube-dl.bash-completion README.txt MANIFEST build/ dist/ .coverage cover/ youtube-dl.tar.gz youtube-dl.zsh youtube-dl.fish *.dump *.part *.info.json *.mp4 *.flv *.mp3 *.avi CONTRIBUTING.md.tmp youtube-dl youtube-dl.exe
 	find . -name "*.pyc" -delete
+	find . -name "*.class" -delete
 
 PREFIX ?= /usr/local
 BINDIR ?= $(PREFIX)/bin
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 210c47fce..91c9d8200 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -465,6 +465,10 @@ def encodeFilename(s, for_subprocess=False):
     if not for_subprocess and sys.platform == 'win32' and sys.getwindowsversion()[0] >= 5:
         return s
 
+    # Jython assumes filenames are Unicode strings though reported as Python 2.x compatible
+    if sys.platform.startswith('java'):
+        return s
+
     return s.encode(get_subprocess_encoding(), 'ignore')
 
 
@@ -1215,13 +1219,23 @@ def _unlock_file(f):
             raise OSError('Unlocking file failed: %r' % ctypes.FormatError())
 
 else:
-    import fcntl
+    # Some platforms, such as Jython, is missing fcntl
+    try:
+        import fcntl
 
-    def _lock_file(f, exclusive):
-        fcntl.flock(f, fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH)
+        def _lock_file(f, exclusive):
+            fcntl.flock(f, fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH)
 
-    def _unlock_file(f):
-        fcntl.flock(f, fcntl.LOCK_UN)
+        def _unlock_file(f):
+            fcntl.flock(f, fcntl.LOCK_UN)
+    except ImportError:
+        UNSUPPORTED_MSG = 'file locking is not supported on this platform'
+
+        def _lock_file(f, exclusive):
+            raise IOError(UNSUPPORTED_MSG)
+
+        def _unlock_file(f):
+            raise IOError(UNSUPPORTED_MSG)
 
 
 class locked_file(object):
@@ -1385,6 +1399,12 @@ def fix_xml_ampersands(xml_str):
 
 def setproctitle(title):
     assert isinstance(title, compat_str)
+
+    # ctypes in Jython is not complete
+    # http://bugs.jython.org/issue2148
+    if sys.platform.startswith('java'):
+        return
+
     try:
         libc = ctypes.cdll.LoadLibrary('libc.so.6')
     except OSError: