class IndexReader {
/** Deletes all documents that have a given <code>term</code> indexed.
* This is useful if one uses a document field to hold a unique ID string for
* the document. Then to delete such a document, one merely constructs a
* term with the appropriate field and the unique ID string as its text and
* passes it to this method.
* See {@link #deleteDocument(int)} for information about when this deletion will
* become effective.
*
* @return the number of documents deleted
* @throws StaleReaderException if the index has changed
* since this reader was opened
* @throws CorruptIndexException if the index is corrupt
* @throws LockObtainFailedException if another writer
* has this index open (<code>write.lock</code> could not
* be obtained)
* @throws IOException if there is a low-level IO error
*/
public int deleteDocuments(Term term) throws StaleReaderException, CorruptIndexException, LockObtainFailedException, IOException {
ensureOpen();
TermDocs docs = termDocs(term);
if (docs == null) return 0;
int n = 0;
try {
while (docs.next()) {
deleteDocument(docs.doc());
n++;
}
} finally {
docs.close();
}
return n;
}
}
