public static void main(String[] args) throws Exception {
// the IndexReader object is the main handle that will give you
// all the documents, terms and inverted index
IndexReader r = IndexReader.open(FSDirectory.open(new File("index")));
// You can figure out the number of documents using the maxDoc() function
System.out.println("The number of documents in this index is: " + r.maxDoc());
int i = 0;
// You can find out all the terms that have been indexed using the terms() function
TermEnum t = r.terms();
while (t.next()) {
// Since there are so many terms, let us try printing only term #100000-#100010
if (i > 100000) System.out.println("[" + i + "] " + t.term().text());
if (++i > 100010) break;
}
// You can create your own query terms by calling the Term constructor, with the field
// 'contents'
// In the following example, the query term is 'brute'
Term te = new Term("contents", "brute");
// You can also quickly find out the number of documents that have term t
System.out.println("Number of documents with the word 'brute' is: " + r.docFreq(te));
// You can use the inverted index to find out all the documents that contain the term 'brute'
// by using the termDocs function
TermDocs td = r.termDocs(te);
while (td.next()) {
System.out.println(
"Document number ["
+ td.doc()
+ "] contains the term 'brute' "
+ td.freq()
+ " time(s).");
}
// You can find the URL of the a specific document number using the document() function
// For example, the URL for document number 14191 is:
Document d = r.document(14191);
String url =
d.getFieldable("path")
.stringValue(); // the 'path' field of the Document object holds the URL
System.out.println(url.replace("%%", "/"));
// -------- Now let us use all of the functions above to make something useful --------
// The following bit of code is a worked out example of how to get a bunch of documents
// in response to a query and show them (without ranking them according to TF/IDF)
Scanner sc = new Scanner(System.in);
String str = "";
System.out.print("query> ");
while (!(str = sc.nextLine()).equals("quit")) {
String[] terms = str.split("\\s+");
for (String word : terms) {
Term term = new Term("contents", word);
TermDocs tdocs = r.termDocs(term);
while (tdocs.next()) {
String d_url =
r.document(tdocs.doc()).getFieldable("path").stringValue().replace("%%", "/");
System.out.println("[" + tdocs.doc() + "] " + d_url);
}
}
System.out.print("query> ");
}
}
public static void main(String[] args) throws Exception {
if (args.length < 2) {
System.err.println("TermDumper [-c|-v value] field <index...>");
System.exit(1);
}
boolean count = false;
String value = null;
boolean all = false;
int i = 0;
for (; i < args.length; i++) {
String arg = args[i];
if ("-h".equals(arg) || "--help".equals(arg)) {
System.err.println("TermDumper [-c|-v value] field <index...>");
System.exit(1);
} else if ("-c".equals(arg) || "--count".equals(arg)) {
count = true;
} else if ("-v".equals(arg) || "--vaue".equals(arg)) {
value = args[++i];
} else if ("-a".equals(arg) || "--all".equals(arg)) {
all = true;
} else {
break;
}
}
String field = args[i++];
java.util.ArrayList<IndexReader> readers =
new java.util.ArrayList<IndexReader>(args.length - 1);
for (; i < args.length; i++) {
String arg = args[i];
try {
IndexReader reader = IndexReader.open(new MMapDirectory(new File(arg)), true);
readers.add(reader);
} catch (IOException ioe) {
System.err.println("Error reading: " + arg);
}
}
for (IndexReader reader : readers) {
TermDocs termDocs = reader.termDocs();
TermEnum termEnum = reader.terms(new Term(field));
try {
do {
Term term = termEnum.term();
if (term == null || !field.equals(term.field())) break;
if (value == null) {
if (count) {
termDocs.seek(termEnum);
int c = 0;
for (; termDocs.next(); c++) ;
System.out.print(c + " ");
}
System.out.println(term.text());
} else if (value.equals(term.text())) {
termDocs.seek(termEnum);
while (termDocs.next()) {
if (all) {
Document d = reader.document(termDocs.doc());
System.out.println(termDocs.doc());
for (Object o : d.getFields()) {
Field f = (Field) o;
System.out.println(f.name() + " " + d.get(f.name()));
}
} else {
System.out.println(
termDocs.doc() + " " + reader.document(termDocs.doc()).get("url"));
}
}
}
} while (termEnum.next());
} finally {
termDocs.close();
termEnum.close();
}
}
}