indexing - Lucene 4.7 long text index -

i'm trying index long texts lucene 4.7, thought fine realise search hits not complete.

after long search found web page said "when try index long text in lucene, lucene index first n characters prevent stackoverflows."

i want index full texts , don't know how ¿some hel please?. here code:

    file indexdir = new file(indexpath);     directory directory = fsdirectory.open(indexdir);     indexwriterconfig config = new indexwriterconfig(version.lucene_47, analyzer);     config.setopenmode(indexwriterconfig.openmode.create);     writer = new indexwriter(directory, config);     document doc = new document();     doc.add(new doublefield("textid", textid, field.store.yes));     doc.add(new textfield("text", text, field.store.no));     doc.add(new textfield("title", title, field.store.no));     doc.add(new stringfield("discourse", discourse, stringfield.store.yes));     writer.adddocument(doc);