Apache Lucene API

X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.4.0/lucene/src/java/overview.html?ds=sidebyside diff --git a/lucene-java-3.4.0/lucene/src/java/overview.html b/lucene-java-3.4.0/lucene/src/java/overview.html deleted file mode 100644 index 4958370..0000000 --- a/lucene-java-3.4.0/lucene/src/java/overview.html +++ /dev/null @@ -1,191 +0,0 @@ - - - - - Apache Lucene API - - - -

Apache Lucene is a high-performance, full-featured text search engine library. -Here's a simple example how to use Lucene for indexing and searching (using JUnit -to check if the results are what we expect):

- - - - - - -

-    Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT);
-
-    // Store the index in memory:
-    Directory directory = new RAMDirectory();
-    // To store an index on disk, use this instead:
-    //Directory directory = FSDirectory.open("/tmp/testindex");
-    IndexWriter iwriter = new IndexWriter(directory, analyzer, true,
-                                          new IndexWriter.MaxFieldLength(25000));
-    Document doc = new Document();
-    String text = "This is the text to be indexed.";
-    doc.add(new Field("fieldname", text, Field.Store.YES,
-        Field.Index.ANALYZED));
-    iwriter.addDocument(doc);
-    iwriter.close();
-    
-    // Now search the index:
-    IndexSearcher isearcher = new IndexSearcher(directory, true); // read-only=true
-    // Parse a simple query that searches for "text":
-    QueryParser parser = new QueryParser("fieldname", analyzer);
-    Query query = parser.parse("text");
-    ScoreDoc[] hits = isearcher.search(query, null, 1000).scoreDocs;
-    assertEquals(1, hits.length);
-    // Iterate through the results:
-    for (int i = 0; i < hits.length; i++) {
-      Document hitDoc = isearcher.doc(hits[i].doc);
-      assertEquals("This is the text to be indexed.", hitDoc.get("fieldname"));
-    }
-    isearcher.close();
-    directory.close();

- - - - - -

The Lucene API is divided into several packages:

- -

-org.apache.lucene.analysis -defines an abstract Analyzer -API for converting text from a java.io.Reader -into a TokenStream, -an enumeration of token Attributes. -A TokenStream can be composed by applying TokenFilters -to the output of a Tokenizer. -Tokenizers and TokenFilters are strung together and applied with an Analyzer. -A handful of Analyzer implementations are provided, including StopAnalyzer -and the grammar-based StandardAnalyzer.
-org.apache.lucene.document -provides a simple Document -class. A Document is simply a set of named Fields, -whose values may be strings or instances of java.io.Reader.
-org.apache.lucene.index -provides two primary classes: IndexWriter, -which creates and adds documents to indices; and IndexReader, -which accesses the data in the index.
-org.apache.lucene.search -provides data structures to represent queries (ie TermQuery -for individual words, PhraseQuery -for phrases, and BooleanQuery -for boolean combinations of queries) and the abstract Searcher -which turns queries into TopDocs. -IndexSearcher -implements search over a single IndexReader.
-org.apache.lucene.queryParser -uses JavaCC to implement a -QueryParser.
-org.apache.lucene.store -defines an abstract class for storing persistent data, the Directory, -which is a collection of named files written by an IndexOutput -and read by an IndexInput. -Multiple implementations are provided, including FSDirectory, -which uses a file system directory to store files, and RAMDirectory -which implements files as memory-resident data structures.
-org.apache.lucene.util -contains a few handy data structures and util classes, ie BitVector -and PriorityQueue.

-To use Lucene, an application should: -

-Create Documents by -adding -Fields;
-Create an IndexWriter -and add documents to it with addDocument();
-Call QueryParser.parse() -to build a query from a string; and
-Create an IndexSearcher -and pass the query to its search() -method.

-Some simple examples of code which does this are: -

- IndexFiles.java creates an -index for all the files contained in a directory.
- SearchFiles.java prompts for -queries and searches an index.

-To demonstrate these, try something like: -

> java -cp lucene.jar:lucene-demo.jar:lucene-analyzers-common.jar org.apache.lucene.demo.IndexFiles rec.food.recipes/soups -
adding rec.food.recipes/soups/abalone-chowder -
[ ... ] - -
> java -cp lucene.jar:lucene-demo.jar:lucene-analyzers-common.jar org.apache.lucene.demo.SearchFiles -
Query: chowder -
Searching for: chowder -
34 total matching documents -
1. rec.food.recipes/soups/spam-chowder -
[ ... thirty-four documents contain the word "chowder" ... ] - -
Query: "clam chowder" AND Manhattan -
Searching for: +"clam chowder" +manhattan -
2 total matching documents -
1. rec.food.recipes/soups/clam-chowder -
[ ... two documents contain the phrase "clam chowder" -and the word "manhattan" ... ] -
[ Note: "+" and "-" are canonical, but "AND", "OR" -and "NOT" may be used. ]

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