source: greenstone3/trunk/web/sites/localsite/collect/gberg/java/Indexer.java@ 20341

import org.greenstone.gsdl3.util.GSEntityResolver;

import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
//import org.xml.sax.SAXParseException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
//import org.apache.lucene.document.DateField;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
//import org.apache.lucene.analysis.SimpleAnalyzer;

import java.util.Stack;
import java.io.FileInputStream;
import java.io.File;
import java.net.URL;



public class Indexer extends DefaultHandler {
    IndexWriter writer = null;
    SAXParser sax_parser = null;
    Stack stack = null;
    String path = "";
    String current_node = "";
    String current_contents = "";
    Document current_doc = null;
    String scope = "";
    protected String file_id = null;
    private String base_path = null;
    /** pass in true if want to create a new index, false if want to use the existing one */
    public Indexer (File index_dir, boolean create) {
    try {
        stack = new Stack();
        SAXParserFactory sax_factory = SAXParserFactory.newInstance();
        sax_parser = sax_factory.newSAXParser();
        writer = new IndexWriter(index_dir.getPath(), new StandardAnalyzer(), create);
        if (create) {
        writer.optimize();
        }

    } catch (Exception e) {

    }
    }

    /** index one document */
    public void index (String file_id, File file) {
    this.file_id = file_id;
    this.path = "";
    this.base_path = file.getPath();
    this.base_path = this.base_path.substring(0, this.base_path.lastIndexOf(File.separatorChar));
    try {
            sax_parser.parse(new InputSource(new FileInputStream(file)), this);
        }
        catch (Exception e) {
        println("parse error:");
            e.printStackTrace();
    }
    }
    
    /** optimise the index */
    public void finish() {
    try {
        writer.optimize();
        writer.close();
    } catch (Exception e) {}
    }

    protected void println(String s) { System.out.println(s); }

    public void startDocument() throws SAXException {
        println("Starting to index " + file_id);
    }
    public void endDocument() throws SAXException {
        println("... indexing finished.");
    }
    public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
    path = appendPathLink(path, qName, atts);
    if (XMLTagInfo.isScopable(qName)) {
        scope = qName;
    }
    if (XMLTagInfo.isIndexable(qName)) {
        pushOnStack();
        current_node = qName;   
        System.out.println("going to index "+qName );
        String node_id = "";
        String id = "<"+qName;
        for (int i=0; i<atts.getLength(); i++) {
        String name = atts.getQName(i);
        String value = atts.getValue(i);
        if (name!=null && value != null) {
            id += " "+name+"="+value;
        }
        if (name.equals("gs3:id")) {
            node_id = value;
        }
        }
        id += "/>";

        if (scope.equals(qName)) {

            current_doc.add(new Field("nodeID", this.file_id+"."+qName,
                      Field.Store.YES,Field.Index.NO));
        } else {
        current_doc.add(new Field("nodeID", this.file_id+"."+scope+"."+qName+"."+node_id,
                      Field.Store.YES,Field.Index.NO));
        }
    }
    }
    public void endElement(String uri, String localName, String qName) throws SAXException {
    if (XMLTagInfo.isIndexable(qName) && qName.equals(current_node)) {
        current_doc.add(new Field("content", current_contents,
                      Field.Store.NO,Field.Index.TOKENIZED));
        try {
        writer.addDocument(current_doc);
        } catch (java.io.IOException e) {
        e.printStackTrace();
        }
        popOffStack();
    }
    
    path = removePathLink(path);
    }

    public void characters(char ch[], int start, int length) throws SAXException {
    String data = new String(ch, start, length).trim();
    if (data.length() > 0 ) {
        current_contents += data;
    }
    }
    
    protected String appendPathLink(String path, String qName, Attributes atts) {

    path = path + "/"+qName;
    if (atts.getLength()>0) {
        String id = atts.getValue("gs3:id");
        if (id != null) {
        path +=  "[@gs3:id='"+id+"']";
        }
    }
    return path;
    }
    protected String  removePathLink(String path) {

    int i=path.lastIndexOf('/');
    if (i==-1) {
        path="";
    } else {
        path = path.substring(0, i);
    }
    return path;
    }
    /** these are what we save on the stack */
    private class MyDocument {

    public Document doc = null;
    public String contents = null;
    public String tagname = "";
    
    }
    protected void pushOnStack() {
    if (current_doc != null) {
        MyDocument save = new MyDocument();
        save.doc = current_doc;
        save.contents = current_contents;
        save.tagname = current_node;
        stack.push(save);
    }
    current_doc = new Document();
    current_contents = "";
    current_node = "";
    }

    protected void popOffStack() {
    if (!stack.empty()) {
        MyDocument saved = (MyDocument)stack.pop();
        current_doc = saved.doc;
        current_contents = saved.contents;
        current_node = saved.tagname;
    } else {
        current_doc = new Document();
        current_contents = "";
        current_node = "";
    }
    }

    public InputSource resolveEntity (String public_id, String system_id) {
    
    if (system_id.startsWith("file://")) {
        return new InputSource(system_id);
    }
    if (!system_id.startsWith(File.separator)) {
        system_id = base_path+File.separatorChar+system_id;
    }
    return new InputSource("file://"+system_id);
    }

}