public static void index(String[] args) {
        String usage = "java org.apache.lucene.demo.IndexFiles"
                + " [-index INDEX_PATH] [-docs DOCS_PATH] [-update]\n\n"
                + "This indexes the documents in DOCS_PATH, creating a Lucene index"
                + "in INDEX_PATH that can be searched with SearchFiles";
        String indexPath = "index2";
        String docsPath = null;
        boolean create = true;
        for (int i = 0; i < args.length; i++) {
            if ("-index".equals(args[i])) {
                indexPath = args[i + 1];
                i++;
            } else if ("-docs".equals(args[i])) {
                docsPath = args[i + 1];
                i++;
            } else if ("-update".equals(args[i])) {
                create = false;
            }
        }

        if (docsPath == null) {
            System.err.println("Usage: " + usage);
            System.exit(1);
        }

        final File docDir = new File(docsPath);
        if (!docDir.exists() || !docDir.canRead()) {
            System.out.println("Document directory '" + docDir.getAbsolutePath() + "' does not exist or is not readable, please check the path");
            System.exit(1);
        }

        Date start = new Date();
        try {
            System.out.println("Indexing to directory '" + indexPath + "'...");

            Directory dir = FSDirectory.open(new File(indexPath));
            // :Post-Release-Update-Version.LUCENE_XY:
            Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_4_10_0);
            IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_4_10_0, analyzer);

            if (create) {
                // Create a new index in the directory, removing any
                // previously indexed documents:
                iwc.setOpenMode(OpenMode.CREATE);
            } else {
                // Add new documents to an existing index:
                iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
            }

            // Optional: for better indexing performance, if you
            // are indexing many documents, increase the RAM
            // buffer.  But if you do this, increase the max heap
            // size to the JVM (eg add -Xmx512m or -Xmx1g):
            //
            // iwc.setRAMBufferSizeMB(256.0);

            IndexWriter writer = new IndexWriter(dir, iwc);
            indexDocs(writer, docDir);

            // NOTE: if you want to maximize search performance,
            // you can optionally call forceMerge here.  This can be
            // a terribly costly operation, so generally it's only
            // worth it when your index is relatively static (ie
            // you're done adding documents to it):
            //
            // writer.forceMerge(1);

            writer.close();

            Date end = new Date();
            System.out.println(end.getTime() - start.getTime() + " total milliseconds");

        } catch (IOException e) {
            System.out.println(" caught a " + e.getClass() +
                    "\n with message: " + e.getMessage());
        }
    }