def train(model_filename, featuresets, quiet=True):
        # Make sure we can find java & weka.
        config_weka()
        
        # Build an ARFF formatter.
        formatter = ARFF_Formatter.from_train(featuresets)
    
        temp_dir = tempfile.mkdtemp()
        try:
            # Write the training data file.
            train_filename = os.path.join(temp_dir, 'train.arff')
            formatter.write(train_filename, featuresets)
    
            # Train the weka model.
            cmd = ['weka.classifiers.bayes.NaiveBayes',
                   '-d', model_filename, '-t', train_filename]
            if quiet: stdout = subprocess.PIPE
            else: stdout = None
            java(cmd, classpath=_weka_classpath, stdout=stdout)

            # Return the new classifier.
            return WekaClassifier(formatter, model_filename)
        
        finally:
            for f in os.listdir(temp_dir):
                os.remove(os.path.join(temp_dir, f))
            os.rmdir(temp_dir)

    def train(cls, model_filename, featuresets,
              classifier='naivebayes', options=[], quiet=True):
        # Make sure we can find java & weka.
        config_weka()
        
        # Build an ARFF formatter.
        formatter = ARFF_Formatter.from_train(featuresets)
    
        temp_dir = tempfile.mkdtemp()
        try:
            # Write the training data file.
            train_filename = os.path.join(temp_dir, 'train.arff')
            formatter.write(train_filename, featuresets)

            if classifier in cls._CLASSIFIER_CLASS:
                javaclass = cls._CLASSIFIER_CLASS[classifier]
            elif classifier in cls._CLASSIFIER_CLASS.values():
                javaclass = classifier
            else:
                raise ValueError('Unknown classifier %s' % classifier)
    
            # Train the weka model.
            cmd = [javaclass, '-d', model_filename, '-t', train_filename]
            cmd += list(options)
            if quiet: stdout = subprocess.PIPE
            else: stdout = None
            java(cmd, classpath=_weka_classpath, stdout=stdout)

            # Return the new classifier.
            return WekaClassifier(formatter, model_filename)
        
        finally:
            for f in os.listdir(temp_dir):
                os.remove(os.path.join(temp_dir, f))
            os.rmdir(temp_dir)

    def batch_tag(self, sentences):
        encoding = self._encoding
        default_options = ' '.join(_java_options)
        config_java(options=self.java_options, verbose=False)

        # Create a temporary input file
        _input_fh, self._input_file_path = tempfile.mkstemp(text=True)

        if encoding:
            self._cmd.extend(['-encoding', encoding])

        # Write the actual sentences to the temporary input file
        _input_fh = os.fdopen(_input_fh, 'w')
        _input = '\n'.join((' '.join(x) for x in sentences))
        if isinstance(_input, compat.text_type) and encoding:
            _input = _input.encode(encoding)
        _input_fh.write(_input)
        _input_fh.close()

        # Run the tagger and get the output
        stanpos_output, _stderr = java(self._cmd,classpath=self._stanford_jar, \
                                                       stdout=PIPE, stderr=PIPE)
        if encoding:
            stanpos_output = stanpos_output.decode(encoding)

        # Delete the temporary file
        os.unlink(self._input_file_path)

        # Return java configurations to their default values
        config_java(options=default_options, verbose=False)

        return self.parse_output(stanpos_output)

    def _batch_classify(self, featuresets, options):
        # Make sure we can find java & weka.
        config_weka()
        
        temp_dir = tempfile.mkdtemp()
        try:
            # Write the test data file.
            test_filename = os.path.join(temp_dir, 'test.arff')
            self._formatter.write(test_filename, featuresets)
            
            # Call weka to classify the data.
            cmd = ['weka.classifiers.bayes.NaiveBayes', 
                   '-l', self._model, '-T', test_filename] + options
            (stdout, stderr) = java(cmd, classpath=_weka_classpath,
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.PIPE)

            # Check if something went wrong:
            if stderr and not stdout:
                if 'Illegal options: -distribution' in stderr:
                    raise ValueError('The installed verison of weka does '
                                     'not support probability distribution '
                                     'output.')
                else:
                    raise ValueError('Weka failed to generate output:\n%s'
                                     % stderr)

            # Parse weka's output.
            return self.parse_weka_output(stdout.split('\n'))

        finally:
            for f in os.listdir(temp_dir):
                os.remove(os.path.join(temp_dir, f))
            os.rmdir(temp_dir)

    def _execute(self, cmd, input_, verbose=False):
        encoding = self._encoding
        cmd.extend(['-charset', encoding])
        _options_cmd = self._options_cmd
        if _options_cmd:
            cmd.extend(['-options', self._options_cmd])

        default_options = ' '.join(_java_options)

        # Configure java.
        config_java(options=self.java_options, verbose=verbose)

        # Windows is incompatible with NamedTemporaryFile() without passing in delete=False.
        with tempfile.NamedTemporaryFile(mode='wb', delete=False) as input_file:
            # Write the actual sentences to the temporary input file
            if isinstance(input_, text_type) and encoding:
                input_ = input_.encode(encoding)
            input_file.write(input_)
            input_file.flush()

            cmd.append(input_file.name)

            # Run the tagger and get the output.
            stdout, stderr = java(cmd, classpath=self._stanford_jar,
                                  stdout=PIPE, stderr=PIPE)
            stdout = stdout.decode(encoding)

        os.unlink(input_file.name)

        # Return java configurations to their default values.
        config_java(options=default_options, verbose=False)

        return stdout

    def tag(self, text, options=['-mx2g']):
        command = ['edu.stanford.nlp.tagger.maxent.MaxentTagger']
        command.extend(['-model', self._model])
        command.extend(['-outputFormat', 'xml'])
        command.extend(['-outputFormatOptions', 'lemmatize'])
        command.extend(options)

        with tempfile.NamedTemporaryFile(mode='wb', delete=False) as text_file:
            text_file.write(text.encode('utf-8'))
            text_file.flush()

            command.extend(['-textFile', text_file.name])

            stderr = subprocess.DEVNULL if not self._verbose else None
            stdout, _ = java(command, classpath=self._libs,
                             stderr=stderr, stdout=subprocess.PIPE)
            output = stdout.decode('utf-8')

        tagged = []
        for line in output.splitlines():
            match = self._xml_regex.fullmatch(line)
            if match:
                tagged.append((match.group(3), match.group(2), match.group(1)))

        return tagged

    def _batch_classify(self, featuresets, options):
        # Make sure we can find java & weka.
        config_weka()

        temp_dir = tempfile.mkdtemp()
        try:
            # Write the test data file.
            test_filename = os.path.join(temp_dir, "test.arff")
            self._formatter.write(test_filename, featuresets)

            # Call weka to classify the data.
            cmd = ["weka.classifiers.bayes.NaiveBayes", "-l", self._model, "-T", test_filename] + options
            (stdout, stderr) = java(cmd, classpath=_weka_classpath, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

            # Check if something went wrong:
            if stderr and not stdout:
                if "Illegal options: -distribution" in stderr:
                    raise ValueError(
                        "The installed version of weka does " "not support probability distribution " "output."
                    )
                else:
                    raise ValueError("Weka failed to generate output:\n%s" % stderr)

            # Parse weka's output.
            return self.parse_weka_output(stdout.decode(stdin.encoding).split("\n"))

        finally:
            for f in os.listdir(temp_dir):
                os.remove(os.path.join(temp_dir, f))
            os.rmdir(temp_dir)

    def _execute(self, cmd, input_, verbose=False):
        encoding = self._encoding
        cmd.extend(['-encoding', encoding])
        if self.corenlp_options:
            cmd.append(self.corenlp_options)

        default_options = ' '.join(_java_options)

        # Configure java.
        config_java(options=self.java_options, verbose=verbose)

        # Windows is incompatible with NamedTemporaryFile() without passing in delete=False.
        with tempfile.NamedTemporaryFile(mode='wb', delete=False) as input_file:
            # Write the actual sentences to the temporary input file
            if isinstance(input_, text_type) and encoding:
                input_ = input_.encode(encoding)
            input_file.write(input_)
            input_file.flush()

            # Run the tagger and get the output.
            if self._USE_STDIN:
                input_file.seek(0)
                stdout, stderr = java(
                    cmd,
                    classpath=self._classpath,
                    stdin=input_file,
                    stdout=PIPE,
                    stderr=PIPE,
                )
            else:
                cmd.append(input_file.name)
                stdout, stderr = java(
                    cmd, classpath=self._classpath, stdout=PIPE, stderr=PIPE
                )

            stdout = stdout.replace(b'\xc2\xa0', b' ')
            stdout = stdout.replace(b'\x00\xa0', b' ')
            stdout = stdout.decode(encoding)

        os.unlink(input_file.name)

        # Return java configurations to their default values.
        config_java(options=default_options, verbose=False)

        return stdout

    def detokenize(self, text, options=['-mx2g']):
        command = ['edu.stanford.nlp.process.PTBTokenizer', '-untok']
        command.extend(options)

        stderr = subprocess.DEVNULL if not self._verbose else None
        jproc = java(command, classpath=self._libs, blocking=False,
                         stderr=stderr, stdout=subprocess.PIPE, stdin=subprocess.PIPE)
        stdout, _ = jproc.communicate(text.encode('utf-8'))
        output = stdout.decode('utf-8')

        return output

def call_mxpost(classpath=None, stdin=None, stdout=None, stderr=None,
                blocking=False):
    if not classpath:
        config_mxpost()
    
    if not classpath:
        classpath = _mxpost_classpath
    elif 'mxpost.jar' not in classpath:
        classpath += ':%s' % _mxpost_classpath
    
    cmd = ['tagger.TestTagger', '%s/%s' % (_mxpost_home, 'wsj-02-21.mxpost')]
    return java(cmd, classpath, stdin, stdout, stderr, blocking)

    def _execute(self, cmd, verbose=False):
        encoding = self._encoding
        #cmd.extend(['-inputEncoding', encoding])
        _options_cmd = self._options_cmd
        if _options_cmd:
            cmd.extend(['-options', self._options_cmd])
 
        default_options = ' '.join(_java_options)
 
        config_java(options=self.java_options, verbose=verbose)     # Configure java.
        stdout, _stderr = java(cmd,classpath=self._stanford_jar, stdout=PIPE, stderr=PIPE)
        stdout = stdout.decode(encoding)
        config_java(options=default_options, verbose=verbose)       # Return java configurations to their default values.
 
        return stdout

def call_mallet(cmd, classpath=None, stdin=None, stdout=None, stderr=None, blocking=True):
    """
    Call `nltk.internals.java` with the given command, and with the classpath
    modified to include both ``nltk.jar`` and all the ``.jar`` files defined by
    Mallet.

    See `nltk.internals.java` for parameter and return value descriptions.
    """
    if _mallet_classpath is None:
        config_mallet()

    # Set up the classpath
    if classpath is None:
        classpath = _mallet_classpath
    else:
        classpath += os.path.pathsep + _mallet_classpath
    # Delegate to java()
    return java(cmd, classpath, stdin, stdout, stderr, blocking)

    def _classify_using_weka(self, test_comments, feature_extractor):
        test_set = nltk.classify.util.apply_features(feature_extractor.extract, test_comments)
        
        temp_dir = tempfile.mkdtemp()
        self.test_filename = os.path.join(temp_dir, 'test.arff')               
        
        logger.info('Writing Test WEKA File: ' + self.test_filename)
        self._write_ARFF_file(self.test_filename, test_set)

        cmd = [self.javaclass, '-t', self.train_filename, '-T', self.test_filename] + ['-p', '0']
        
        logger.info('Executing WEKA: ' + str(cmd))
        
        config_java(options='-Xmx2000M')
        (stdout, stderr) = java(cmd, classpath=weka_classpath,
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.PIPE)
        
        return self.parse_weka_output(stdout.split('\n'))

    def _batch_classify(self, featuresets, options):
        # Make sure we can find java & weka.
        config_weka()
        
        temp_dir = tempfile.mkdtemp()
        try:
            # Write the test data file.
            test_filename = os.path.join(temp_dir, 'test.arff')
            self._formatter.write(test_filename, featuresets)
            
            # Call weka to classify the data.
            cmd = ['weka.classifiers.bayes.NaiveBayes', 
                   '-l', self._model, '-T', test_filename] + options
            (stdout, stderr) = java(cmd, classpath=_weka_classpath,
                                    stdout=subprocess.PIPE)

            # Parse weka's output.
            return self.parse_weka_output(stdout.split('\n'))

        finally:
            for f in os.listdir(temp_dir):
                os.remove(os.path.join(temp_dir, f))
            os.rmdir(temp_dir)

    def start(self):
        import requests

        cmd = ['edu.stanford.nlp.pipeline.StanfordCoreNLPServer']

        if self.corenlp_options:
            cmd.extend(self.corenlp_options)

        # Configure java.
        default_options = ' '.join(_java_options)
        config_java(options=self.java_options, verbose=self.verbose)

        try:
            # TODO: it's probably a bad idea to pipe stdout, as it will
            #       accumulate when lots of text is being parsed.
            self.popen = java(
                cmd,
                classpath=self._classpath,
                blocking=False,
                stdout='pipe',
                stderr='pipe',
            )
        finally:
            # Return java configurations to their default values.
            config_java(options=default_options, verbose=self.verbose)

        # Check that the server is istill running.
        returncode = self.popen.poll()
        if returncode is not None:
            _, stderrdata = self.popen.communicate()
            raise CoreNLPServerError(
                returncode,
                'Could not start the server. '
                'The error was: {}'.format(stderrdata.decode('ascii'))
            )

        for i in range(30):
            try:
                response = requests.get(requests.compat.urljoin(self.url, 'live'))
            except requests.exceptions.ConnectionError:
                time.sleep(1)
            else:
                if response.ok:
                    break
        else:
            raise CoreNLPServerError(
                'Could not connect to the server.'
            )

        for i in range(60):
            try:
                response = requests.get(requests.compat.urljoin(self.url, 'ready'))
            except requests.exceptions.ConnectionError:
                time.sleep(1)
            else:
                if response.ok:
                    break
        else:
            raise CoreNLPServerError(
                'The server is not ready.'
            )