【Lucene4.8教程之四】分析

		Directory returnIndexDir = FSDirectory.open(indexDir);

		IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_48,
				new StandardAnalyzer(Version.LUCENE_48));

		IndexWriter writer = new IndexWriter(returnIndexDir, iwc);

QueryParser parser = new QueryParser(Version.LUCENE_48, "contents",
				new SimpleAnalyzer(Version.LUCENE_48));

• WhitespaceAnalyzer, as the name implies, simply splits text into tokens on whitespace characters and makes no other effort to normalize the tokens.
• SimpleAnalyzer first splits tokens at non-letter characters, then lowercases each token. Be careful! This analyzer quietly discards numeric characters.
• StopAnalyzer is the same as SimpleAnalyzer, except it removes common words (called stop words, described more in section XXX). By default it removes common words in the English language (the, a, etc.), though you can pass in your own set.
• StandardAnalyzer is Lucene’s most sophisticated core analyzer. It has quite a bit of logic to identify certain kinds of tokens, such as company names,

<span>		</span>IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_48,
<span>				</span>new StandardAnalyzer(Version.LUCENE_48));

<span>		</span>writer = new IndexWriter(returnIndexDir, iwc);

便在每次向writer中加入文档时。能够针对该文档指定一个分析器，如

writer.addDocument(doc, new SimpleAnalyzer(Version.LUCENE_48));