java是Lucene 4中允许对数值字段进行范围查询的最简单方法
我正在重温最初为Lucene 3.0编写的代码(然后我对其进行了更新,使其适用于4.0,但尚未充分利用4.0的所有改进)
对于我希望能够进行范围查询的数字字段,我将字段添加到文档中,如下所示:
BytesRef bytes = new BytesRef(NumericUtils.BUF_SIZE_INT);
NumericUtils.intToPrefixCoded(value, 0, bytes);
doc.add(new Field(fieldname, bytes.utf8ToString(),
new FieldType(StringField.TYPE_NOT_STORED)));
然后我必须有一个自定义的查询解析器来覆盖方法newTermQuery()和new RangeQuery()
即
public class ReleaseQueryParser extends MultiFieldQueryParser
{
public ReleaseQueryParser(String[] strings, Analyzer a)
{
super(LuceneVersion.LUCENE_VERSION, strings, a);
}
protected Query newTermQuery(Term term)
{
if (
(term.field().equals(ReleaseIndexField.NUM_TRACKS.getName())) ||
(term.field().equals(ReleaseIndexField.NUM_TRACKS_MEDIUM.getName())) ||
(term.field().equals(ReleaseIndexField.NUM_MEDIUMS.getName()))
)
{
try
{
int number = Integer.parseInt(term.text());
BytesRef bytes = new BytesRef(NumericUtils.BUF_SIZE_INT);
NumericUtils.intToPrefixCoded(number, 0, bytes);
TermQuery tq = new TermQuery(new Term(term.field(), bytes.utf8ToString()));
return tq;
}
catch (NumberFormatException nfe)
{
//If not provided numeric argument just leave as is, won't give matches
return super.newTermQuery(term);
}
}
else
{
return super.newTermQuery(term);
}
}
@Override
public Query newRangeQuery(String field,
String part1,
String part2,
boolean startInclusive,
boolean endInclusive)
{
if (
(field.equals(ReleaseIndexField.NUM_TRACKS.getName())) ||
(field.equals(ReleaseIndexField.NUM_TRACKS_MEDIUM.getName())) ||
(field.equals(ReleaseIndexField.NUM_MEDIUMS.getName()))
)
{
BytesRef bytes1 = new BytesRef(NumericUtils.BUF_SIZE_INT);
BytesRef bytes2 = new BytesRef(NumericUtils.BUF_SIZE_INT);
NumericUtils.intToPrefixCoded(Integer.parseInt(part1), 0, bytes1);
NumericUtils.intToPrefixCoded(Integer.parseInt(part2), 0, bytes2);
part1 = bytes1.utf8ToString();
part2 = bytes2.utf8ToString();
}
TermRangeQuery query = (TermRangeQuery)
super.newRangeQuery(field, part1, part2, startInclusive, endInclusive);
return query;
}
}
我一直认为这段代码很笨重,想知道它现在是否可以简化一些
更新
试图按如下方式使用IntField
医生。添加(新的IntField(field.getName(),value,新的FieldType(StringField.TYPE_NOT_STORED))
编译好了,但我的索引构建测试方法
Fields fields = MultiFields.getFields(ir);
Terms terms = fields.terms(field.getName());
TermsEnum termsEnum = terms.iterator(null);
termsEnum.next();
assertEquals(value, NumericUtils.prefixCodedToInt(termsEnum.term()));
因条款上的NullPointerException而失败。迭代器()行
改为
doc.add(new IntField(field.getName(), value, new FieldType(IntField.TYPE_NOT_STORED)));
这很管用,但令我惊讶的是
NumericUtils.prefixCodedToInt(termsEnum.term())
仍然有效,我猜IntField只是我最初拥有的ByteRef代码的包装器
然后重写QueryParser,如下所示
public class ReleaseQueryParser extends MultiFieldQueryParser
{
public ReleaseQueryParser(String[] strings, Analyzer a)
{
super(LuceneVersion.LUCENE_VERSION, strings, a);
}
protected Query newTermQuery(Term term)
{
if (
(term.field().equals(ReleaseIndexField.NUM_TRACKS.getName())) ||
(term.field().equals(ReleaseIndexField.NUM_TRACKS_MEDIUM.getName())) ||
(term.field().equals(ReleaseIndexField.NUM_MEDIUMS.getName()))
)
{
return NumericRangeQuery.newIntRange(term.field(), Integer.parseInt(term.text()), Integer.parseInt(term.text()), true, true);
}
else
{
return super.newTermQuery(term);
}
}
@Override
public Query newRangeQuery(String field,
String part1,
String part2,
boolean startInclusive,
boolean endInclusive)
{
if (
(field.equals(ReleaseIndexField.NUM_TRACKS.getName())) ||
(field.equals(ReleaseIndexField.NUM_TRACKS_MEDIUM.getName())) ||
(field.equals(ReleaseIndexField.NUM_MEDIUMS.getName()))
)
{
return NumericRangeQuery.newIntRange(field, Integer.parseInt(part1), Integer.parseInt(part2),startInclusive, endInclusive);
}
else
{
return super.newRangeQuery(field, part1, part2, startInclusive, endInclusive);
}
}
}
这很管用,我真的不想在newTermQuery(术语)中使用范围查询,但我找不到更简单的方法
# 1 楼答案
使用lucene提供的
IntField
或LongField
类。然后,您可以使用指定类型的标准NumericRangeQuery
查询索引