cn.juque.lucenecandy.helper.LuceneHelper 对lucene的增删改查API进行了统一封装，目的在提供较为统一的API调度。
- 查询
该方法根据查询条件返回文档集合。需要注意的是，该方法的响应时间与返回的结果集成正比，所以使用该方法应合理评估涉及的结果集大小。
public List<Document> search(String index, BooleanQuery.Builder builder, Sort sort, Set<String> fieldToLoad) {
Assert.notNull(index);
Assert.notNull(builder);
Assert.notNull(sort);
try {
long start = System.currentTimeMillis();
IndexReader indexReader = this.indexReaderCache.get(index, false);
IndexSearcher indexSearcher = new IndexSearcher(indexReader);
int size = 10000;
TopDocs topDocs;
ScoreDoc lastDoc = null;
List<Document> result = CollUtil.newArrayList();
do {
topDocs = indexSearcher.searchAfter(lastDoc, builder.build(), size, sort);
if (topDocs.scoreDocs.length > 0) {
lastDoc = topDocs.scoreDocs[topDocs.scoreDocs.length - 1];
result.addAll(this.toDocument(indexSearcher, topDocs, fieldToLoad));
}
} while (topDocs.scoreDocs.length > 0);
long cost = System.currentTimeMillis() - start;
log.debug("search index:{} query:{}, size:{}, cost:{}ms", index, builder.build(), CollUtil.size(result), cost);
return result;
} catch (IndexNotFoundException e) {
return new ArrayList<>(0);
} catch (Exception e) {
log.error("search index:{} 查询异常", index, e);
}
throw new AppException(MessageEnum.SYSTEM_ERROR);
}
- 分页查询
lucene并没有提供类似mysql的分页查询API，所以，我做了一次页数合并，只考虑两种情况：第一页和非第一页。第一页很好理解，直接限定返回数量即可；非第一页则是把(n-1)页合并起来，查询出(n-1)的最后一个文档，从(n-1)开始限定返回数量。这个查询逻辑成立的前提是，排序条件必不可少！
public List<Document> searchByPage(String index, BooleanQuery.Builder builder, Sort sort, PageInfo pageInfo, Set<String> fieldToLoad) {
long start = System.currentTimeMillis();
List<Document> docList;
try {
IndexReader indexReader = this.indexReaderCache.get(index, false);
IndexSearcher indexSearcher = new IndexSearcher(indexReader);
// 查询出前一页最后一条记录，然后再查当前页
if (pageInfo.getPage() <= 1) {
TopDocs topDocs = indexSearcher.search(builder.build(), pageInfo.getLimit(), sort);
pageInfo.setTotal(topDocs.totalHits.value);
docList = this.toDocument(indexSearcher, topDocs, fieldToLoad);
} else {
int size = pageInfo.getLimit() * (pageInfo.getPage() - 1);
TopDocs topDocs = indexSearcher.search(builder.build(), size, sort);
ScoreDoc lastDoc = topDocs.scoreDocs[topDocs.scoreDocs.length - 1];
topDocs = indexSearcher.searchAfter(lastDoc, builder.build(), pageInfo.getLimit(), sort);
pageInfo.setTotal(topDocs.totalHits.value);
docList = this.toDocument(indexSearcher, topDocs, fieldToLoad);
}
long end = System.currentTimeMillis() - start;
if (end > 0) {
log.debug("searchByPage index:{} query:{}, size:{}, cost time:{}ms", index, builder.build(), pageInfo.getTotal(), end);
}
return docList;
} catch (IndexNotFoundException e) {
return new ArrayList<>(0);
} catch (Exception e) {
log.error(" index:{} document searchByPage error", index, e);
}
throw new AppException(MessageEnum.SYSTEM_ERROR);
}
- 新增文档
public void addDocuments(String index, List<Document> docList) {
if (CollUtil.isEmpty(docList)) {
return;
}
IndexWriter indexWriter = this.indexWriterCache.get(index, false);
try {
indexWriter.addDocuments(docList);
} catch (Exception e) {
log.error(" index:{} add documents error", index, e);
throw new AppException(MessageEnum.SYSTEM_ERROR);
}
}
- 根据条件更新文档
lucene的更新操作可以理解为“先删除，后新增”，区别于关系型数据库的更新，是整个文档的所有字段的全量更新。
public void updateByQuery(String index, Query query, Document document) {
IndexWriter indexWriter = this.indexWriterCache.get(index, false);
try {
// 删除
indexWriter.deleteDocuments(query);
// 新增
indexWriter.addDocument(document);
} catch (Exception e) {
log.error(" index:{} update document error", index, e);
throw new AppException(MessageEnum.SYSTEM_ERROR);
}
}
- 根据查询条件删除文档
public void deleteDocuments(String index, Query... query) {
IndexWriter indexWriter = this.indexWriterCache.get(index, false);
try {
indexWriter.deleteDocuments(query);
} catch (Exception e) {
log.error(" index:{} delete document error", index, e);
throw new AppException(MessageEnum.SYSTEM_ERROR);
}
}
