建立數值索引是用 NumericField 取代原本的 Field，查詢數值索引時改用 NumericRangeQuery。
另外，除了純數值欄位外，還有一種文數字混合的欄位，也就是字串裡有數值存在，這可以當作是一種文字來處理。
public class RangeTestCase extends TestCase {
private static final Version VERSION = Version.LUCENE_36;
private static final String F_TITLE = "title";
private static final String F_PRICE = "price";
private static final String F_PUBLICATION_TIME = "pTime";
private Directory directory = new RAMDirectory();
private IndexWriter writer;
private IndexReader reader;
private IndexSearcher searcher;
@Override
protected void setUp() throws Exception {
super.setUp();
// create index
this.writer = this.createWriter();
// this.writer.setInfoStream(System.out);
System.out.println("addDocument...");
this.writer.addDocument(this.createDocument("Lucene in action", 44.95,
new Date(104, 11, 1)));
this.writer.addDocument(this.createDocument("Lucene in action, 2 Edition",
49.99, new Date(110, 6, 28)));
this.writer.addDocument(this.createDocument("Spring in action", 7.89,
new Date(104, 11, 1)));
this.writer.addDocument(this.createDocument("Spring in action, 2 Edition",
11.44, new Date(107, 7, 23)));
this.writer.addDocument(this.createDocument("Spring in action, 3 Edition",
49.99, new Date(111, 5, 29)));
System.out.println("commit...");
// 資料太多時，可以分批 commit
// commit後（沒有close）就可以使用 IndexReader
this.writer.commit();
// 沒有 close 或 commit，不能使用 IndexReader
// this.closeWriter();
}
private Document createDocument(String title, double price, Date date) {
Document doc = new Document();
// 文字欄位用 Field
doc.add(new Field(RangeTestCase.F_TITLE, title, Field.Store.YES,
Field.Index.ANALYZED));
// 數值欄位用 NumericField
doc.add(new NumericField(RangeTestCase.F_PRICE, Field.Store.YES, true).setDoubleValue(price));
// 日期欄位一樣是用 NumericField，只要轉成 long 值就可以了
doc.add(new NumericField(RangeTestCase.F_PUBLICATION_TIME, Field.Store.YES,
true).setLongValue(date.getTime()));
return doc;
}
@Override
protected void tearDown() throws Exception {
super.tearDown();
this.closeWriter();
this.closeSearcher();
}
/**
* 查詢文字中的數字
*/
public void testTextWithNumberQuery() {
System.out.println("testTextWithNumberQuery...");
try {
// 必須用 WhitespaceAnalyzer 或 StandardAnalyzer
// 不可用會丟掉數字的 SimpleAnalyzer 或 StopAnalyzer
IndexSearcher searcher = this.createSearcher();
TopDocs hits = searcher.search(new TermQuery(new Term(
RangeTestCase.F_TITLE, "3")), 100);
this.showDocuments(searcher, hits);
assertEquals(1, hits.totalHits);
}
catch (IOException e) {
Assert.fail(e.getMessage());
}
}
/**
* 查詢數值欄位，包含起訖
*/
public void testNumericRangeQueryInclusive() {
System.out.println("testNumericRangeQueryInclusive...");
try {
// 查詢 double
NumericRangeQuery<Double> q = NumericRangeQuery.newDoubleRange(
RangeTestCase.F_PRICE, 7.89, 44.95, true, true);
IndexSearcher searcher = this.createSearcher();
TopDocs hits = searcher.search(q, 100);
this.showDocuments(searcher, hits);
assertEquals(3, hits.totalHits);
}
catch (IOException e) {
Assert.fail(e.getMessage());
}
}
/**
* 查詢數值欄位，不包含起訖
*/
public void testNumericRangeQueryExclusive() {
System.out.println("testNumericRangeQueryExclusive...");
try {
// 查詢 double
NumericRangeQuery<Double> q = NumericRangeQuery.newDoubleRange(
RangeTestCase.F_PRICE, 7.89, 44.95, false, false);
IndexSearcher searcher = this.createSearcher();
TopDocs hits = searcher.search(q, 100);
this.showDocuments(searcher, hits);
assertEquals(1, hits.totalHits);
}
catch (IOException e) {
Assert.fail(e.getMessage());
}
}
/**
* 查詢日期欄位，包含起訖
*/
public void testDateRangeQuery() {
System.out.println("testDateRangeQuery...");
try {
// 查詢 long 日期
NumericRangeQuery<Long> q = NumericRangeQuery.newLongRange(
RangeTestCase.F_PUBLICATION_TIME, new Date(107, 7, 23).getTime(),
new Date(110, 6, 28).getTime(), true, true);
IndexSearcher searcher = this.createSearcher();
TopDocs hits = searcher.search(q, 100);
this.showDocuments(searcher, hits);
assertEquals(2, hits.totalHits);
}
catch (IOException e) {
Assert.fail(e.getMessage());
}
}
/**
* 倒出文章
*/
private void showDocuments(IndexSearcher searcher, TopDocs hits)
throws CorruptIndexException, IOException {
Document d;
for (ScoreDoc sd : hits.scoreDocs) {
d = searcher.doc(sd.doc);
System.out.println(d.get(F_TITLE) + " - " + d.get(F_PRICE) + " - "
+ new Date(Long.parseLong(d.get(F_PUBLICATION_TIME))));
}
}
private IndexWriter createWriter() throws CorruptIndexException,
LockObtainFailedException, IOException {
IndexWriterConfig config = new IndexWriterConfig(RangeTestCase.VERSION,
new StandardAnalyzer(RangeTestCase.VERSION));
config.setOpenMode(OpenMode.CREATE);
return new IndexWriter(this.directory, config);
}
private IndexSearcher createSearcher() throws CorruptIndexException,
IOException {
return new IndexSearcher(this.createReader());
}
private IndexReader createReader() throws CorruptIndexException, IOException {
return IndexReader.open(this.directory);
}
private void closeWriter() {
if (this.writer != null) {
try {
this.writer.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
private void closeSearcher() {
this.closeReader();
if (this.searcher != null) {
try {
this.searcher.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
private void closeReader() {
if (this.reader != null) {
try {
this.reader.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
}
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