Lucene

http://lucene.apache.org/core/3_6_1/demo.html

CLASSPATH

• OK
• export CLASSPATH=/home/mac/xxxx/xxx/xxx.jar:/home/mac/yyyy/yyy/yyy.jar
• export CLASSPATH=/home/mac/xxxx/xxx/*:/home/mac/yyyy/yyy/*
• Not OK
• export CLASSPATH=/home/mac/xxxx/xxx/*.jar:/home/mac/yyyy/yyy/*.jar
• export CLASSPATH=/home/mac/xxxx/xxx/:/home/mac/yyyy/yyy/

http://lucene.apache.org/core/3_6_1/demo2.html

• Need to detect doc language and change to use correct analyzer.

Create Index

• open an directory to put index files (dir)
• new an Analyzer (analyzer)
• new an IndexWriterConfig (iwc)
• do some settings on IndexWriterConfig
• use dir and iwc to new a IndexWriter (writer)
• add documents
• new a Document (doc)
• add several fields
• new a Field (pathField)
• Field pathField = new Field("path", file.getPath(), Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS);
• pathField.setIndexOptions(IndexOptions.DOCS_ONLY);
• doc.add(pathField);
• new a NumericField (modifiedField)
• NumericField modifiedField = new NumericField("modified");
• modifiedField.setLongValue(file.lastModified());
• doc.add(modifiedField);
• Add real content by reading actual file
• doc.add(new Field("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));
• Add / Update index
• Add: writer.addDocument(doc);
• Update: writer.updateDocument(new Term("path", file.getPath()), doc);
• close writer

Search

• Create an IndexReader by assigning a directory (reader)
• new a IndexSearcher by assign reader (searcher)
• new an Analyzer (analyzer)
• new a QueryParser (parser) // need to indicate which field will be searched.
• QueryParser parser = new QueryParser(Version.LUCENE_31, field, analyzer);
• create Query (query)
• Query query = parser.parse(line)
• do search
• Normal search
• searcher.search(query, null, 100); // get top 100 hits. (null is for filter)
• Do search with paging
• There is a simple sample code in the demo source