elasticsearch 常用API调用

常用API调用"/>

elasticsearch 常用API调用

前言

本文是对 23个最有用的Elasticseaerch检索技巧 一文提到的ES检索技巧进行 Java API 的简单实现，但仅限于简单实现，并不考虑包括参数校验，异常处理，日志处理，安全等问题，仅供参考

代码见 UsefullESSearchSkill ,原查询语句请对照原文

运行环境

JDK version : 10.0.2
gradle version : 4.7
Elasticsearch version : 6.3.2
IDEA version : 2018.2

运行前请启动 ES 实例，并修改 application.properties 文件中的ES配置

类介绍

实体类 Book

注意：日期 publish_date 的类型设置为 String 是避免 Java 到 ES 之间复杂的转换工作，在ES中该字段仍然被识别为 date 类型

public class Book {public static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");private String id;private String title;private List<String> authors;private String summary;private String publish_date;private Integer num_reviews;private String publisher;...
}

公共类 Constants

定义了一些常用的常量

public class Constants {// 字段名public static String ID = "id";public static String TITLE = "title";public static String AUTHORS = "authors";public static String SUMMARY = "summary";public static String PUBLISHDATE = "publish_date";public static String PUBLISHER = "publisher";public static String NUM_REVIEWS = "num_reviews";public static String TITLE_KEYWORD = "title.keyword";public static String PUBLISHER_KEYWORD = "publisher.keyword";// 过滤要返回的字段public static String[] fetchFieldsTSPD = {ID, TITLE, SUMMARY, PUBLISHDATE};public static String[] fetchFieldsTA = {ID, TITLE, AUTHORS};public static String[] fetchFieldsSA = {ID, SUMMARY, AUTHORS};public static String[] fetchFieldsTSA = {ID, TITLE, SUMMARY, AUTHORS};public static String[] fetchFieldsTPPD = {ID, TITLE, PUBLISHER, PUBLISHDATE};public static String[] fetchFieldsTSPN = {ID, TITLE, SUMMARY, PUBLISHER, NUM_REVIEWS};// 高亮public static HighlightBuilder highlightS = new HighlightBuilder().field(SUMMARY);
}

公共类 EsConfig

创建 ES 客户端实例，ES 客户端用于与 ES 集群进行交互

@Configuration
public class EsConfig {@Value("${elasticsearch.cluster-nodes}")private String clusterNodes;@Value("${elasticsearch.cluster-name}")private String clusterName;@Beanpublic Client client() {Settings settings = Settings.builder().put("cluster.name", clusterName).put("client.transport.sniff", true).build();TransportClient client = new PreBuiltTransportClient(settings);try {if (clusterNodes != null && !"".equals(clusterNodes)) {for (String node : clusterNodes.split(",")) {String[] nodeInfo = node.split(":");client.addTransportAddress(new TransportAddress(InetAddress.getByName(nodeInfo[0]), Integer.parseInt(nodeInfo[1])));}}} catch (UnknownHostException e) {}return client;}
}

数据获取工具类 DataUtil

这里的数据也就是 23个最有用的ES检索技巧 文中用于实验的4条数据

public class DataUtil {public static SimpleDateFormat dateFormater = new SimpleDateFormat("yyyy-MM-dd");/*** 模拟获取数据*/public static List<Book> batchData() {List<Book> list = new LinkedList<>();Book book1 = new Book("1", "Elasticsearch: The Definitive Guide", Arrays.asList("clinton gormley", "zachary tong"),"A distibuted real-time search and analytics engine", "2015-02-07", 20, "oreilly");Book book2 = new Book("2", "Taming Text: How to Find, Organize, and Manipulate It", Arrays.asList("grant ingersoll", "thomas morton", "drew farris"),"organize text using approaches such as full-text search, proper name recognition, clustering, tagging, information extraction, and summarization","2013-01-24", 12, "manning");Book book3 = new Book("3", "Elasticsearch in Action", Arrays.asList("radu gheorge", "matthew lee hinman", "roy russo"),"build scalable search applications using Elasticsearch without having to do complex low-level programming or understand advanced data science algorithms","2015-12-03", 18, "manning");Book book4 = new Book("4", "Solr in Action", Arrays.asList("trey grainger", "timothy potter"), "Comprehensive guide to implementing a scalable search engine using Apache Solr","2014-04-05", 23, "manning");list.add(book1);list.add(book2);list.add(book3);list.add(book4);return list;}public static Date parseDate(String dateStr) {try {return dateFormater.parse(dateStr);} catch (ParseException e) {}return null;}

公共查询工具类 CommonQueryUtils

对执行完ES查询请求后的数据进行解析

public class CommonQueryUtils {public static Gson gson = new GsonBuilder().setDateFormat("YYYY-MM-dd").create();/*** 处理ES返回的数据，封装*/public static List<Book> parseResponse(SearchResponse searchResponse) {List<Book> list = new LinkedList<>();for (SearchHit hit : searchResponse.getHits().getHits()) {// 用gson直接解析Book book = gson.fromJson(hit.getSourceAsString(), Book.class);list.add(book);}return list;}/*** 解析完数据后，构建 Response 对象*/public static Response<List<Book>> buildResponse(SearchResponse searchResponse) {// 超时处理if (searchResponse.isTimedOut()) {return new Response<>(ResponseCode.ESTIMEOUT);}// 处理ES返回的数据List<Book> list = parseResponse(searchResponse);// 有shard执行失败if (searchResponse.getFailedShards() > 0) {return new Response<>(ResponseCode.FAILEDSHARDS, list);}return new Response<>(ResponseCode.OK, list);}...
}

数据准备

BulkTests

创建索引，以及使用 bulk API 批量插入数据

@RunWith(SpringRunner.class)
@SpringBootTest
public class BulkTests {// 在Test中 Autowired需要引入包 org.elasticsearch.plugin:transport-netty4-client:6.3.2，否则异常找不到Transport类@Autowiredprivate Client client;@Value("${elasticsearch.bookIndex}")private String bookIndex;@Value("${elasticsearch.bookType}")private String bookType;private Gson gson = new GsonBuilder().setDateFormat("YYYY-MM-dd").create();/*** 创建索引，设置 settings，设置mappings*/@Testpublic void createIndex() {int settingShards = 1;int settingReplicas = 0;// 判断索引是否存在，存在则删除IndicesExistsResponse indicesExistsResponse = client.admin().indices().prepareExists(bookIndex).get();if (indicesExistsResponse.isExists()) {System.out.println("索引 " + bookIndex + " 存在！");// 删除索引，防止报异常  ResourceAlreadyExistsException[index [bookdb_index/yL05ZfXFQ4GjgOEM5x8tFQ] already existsDeleteIndexResponse deleteResponse = client.admin().indices().prepareDelete(bookIndex).get();if (deleteResponse.isAcknowledged()){System.out.println("索引" + bookIndex + "已删除");}else {System.out.println("索引" + bookIndex + "删除失败");}} else {System.out.println("索引 " + bookIndex + " 不存在！");}// 设置SettingsCreateIndexResponse response = client.admin().indices().prepareCreate(bookIndex).setSettings(Settings.builder().put("index.number_of_shards", settingShards).put("index.number_of_replicas", settingReplicas)).get();// 查看结果GetSettingsResponse getSettingsResponse = client.admin().indices().prepareGetSettings(bookIndex).get();System.out.println("索引设置结果");for (ObjectObjectCursor<String, Settings> cursor : getSettingsResponse.getIndexToSettings()) {String index = cursor.key;Settings settings = cursor.value;Integer shards = settings.getAsInt("index.number_of_shards", null);Integer replicas = settings.getAsInt("index.number_of_replicas", null);System.out.println("index:" + index + ", shards:" + shards + ", replicas:" + replicas);Assert.assertEquals(java.util.Optional.of(settingShards), java.util.Optional.of(shards));Assert.assertEquals(java.util.Optional.of(settingReplicas), java.util.Optional.of(replicas));}}/*** Bulk 批量插入数据*/@Testpublic void bulk() {List<Book> list = DateUtil.batchData();BulkRequestBuilder bulkRequestBuilder = client.prepareBulk();// 添加index操作到 bulk 中list.forEach(book -> {// 新版的API中使用setSource时，参数的个数必须是偶数，否则需要加上 setSource(json, XContentType.JSON)bulkRequestBuilder.add(client.prepareIndex(bookIndex, bookType, book.getId()).setSource(gson.toJson(book), XContentType.JSON));});BulkResponse responses = bulkRequestBuilder.get();if (responses.hasFailures()) {// bulk有失败for (BulkItemResponse res : responses) {System.out.println(res.getFailure());}Assert.assertTrue(false);}}
}

开始查询

控制类

查询接口

@RestController
@RequestMapping("basicmatch")
public class BasicMatchQueryController {@Autowiredprivate BasicMatchQueryService basicMatchQueryService;/*** 1.1 对 "guide" 执行全文检索* 测试：http://localhost:8080/basicmatch/multimatch?query=guide*/@RequestMapping("multimatch")public Response<List<Book>> multiMatch(@RequestParam(value = "query", required = true) String query) {return basicMatchQueryService.multiBatch(query);}/*** 1.2 指定特定字段检索* 测试：http://localhost:8080/basicmatch/match?title=in action&from=0&size=4*/@RequestMapping("match")public ResponsePage<List<Book>> match(MatchForm form) {return basicMatchQueryService.match(form);}/*** 2 对 "guide" 执行多字段检索* 测试：http://localhost:8080/basicmatch/multifield?query=guide*/@RequestMapping("multifield")public Response<List<Book>> multiField(@RequestParam(value = "query", required = true) String query) {return basicMatchQueryService.multiField(query);}/*** 3、 Boosting提升某字段得分的检索( Boosting): 将“摘要”字段的得分提高了3倍* 测试：http://localhost:8080/basicmatch/multifieldboost?query=elasticsearch guide*/@RequestMapping("multifieldboost")public Response<List<Book>> multiFieldboost(@RequestParam(value = "query", required = true) String query) {return basicMatchQueryService.multiFieldboost(query);}/*** 4、Bool检索( Bool Query)* 测试：http://localhost:8080/basicmatch/bool?shouldTitles=Elasticsearch&shouldTitles=Solr&mustAuthors=clinton gormely&mustNotAuthors=radu gheorge*/@RequestMapping("bool")public Response<List<Book>> bool(@ModelAttribute BoolForm form) {return basicMatchQueryService.bool(form);}/*** 5、 Fuzzy 模糊检索( Fuzzy Queries)*/@RequestMapping("fuzzy")public Response<List<Book>> fuzzy(String query) {return basicMatchQueryService.fuzzy(query);}/*** 6、 Wildcard Query 通配符检索* 测试：http://localhost:8080/basicmatch/wildcard?pattern=t**/@RequestMapping("wildcard")public Response<List<Book>> wildcard(String pattern) {return basicMatchQueryService.wildcard(Constants.AUTHORS, pattern);}/*** 7、正则表达式检索( Regexp Query)* 测试：http://localhost:8080/basicmatch/regexp*/@RequestMapping("regexp")public Response<List<Book>> regexp(String regexp) {// 由于Tomcat的原因，直接接收有特殊字符的 正则表达式 会异常，所以这里写死，不过多探究// 若regexp = "t[a-z]*y";return basicMatchQueryService.regexp(Constants.AUTHORS, regexp);}/*** 8、匹配短语检索( Match Phrase Query)* 测试：http://localhost:8080/basicmatch/phrase?query=search engine*/@RequestMapping("phrase")public Response<List<Book>> phrase(String query) {return basicMatchQueryService.phrase(query);}/*** 9、匹配词组前缀检索* 测试：http://localhost:8080/basicmatch/phraseprefix?query=search en*/@RequestMapping("phraseprefix")public Response<List<Book>> phrasePrefix(String query) {return basicMatchQueryService.phrasePrefix(query);}/*** 10、字符串检索（ Query String）* 测试：http://localhost:8080/basicmatch/querystring?query=(saerch~1 algorithm~1) AND (grant ingersoll)  OR (tom morton)*/@RequestMapping("querystring")public Response<List<Book>> queryString(String query) {return basicMatchQueryService.queryString(query);}/*** 11、简化的字符串检索 （Simple Query String）* 测试：http://localhost:8080/basicmatch/simplequerystring?query=(saerch~1 algorithm~1) AND (grant ingersoll)  OR (tom morton)*/@RequestMapping("simplequerystring")public Response<List<Book>> simplequerystring(String query) {// 这里写死，仅为测试query = "(saerch~1 algorithm~1) + (grant ingersoll)  | (tom morton)";return basicMatchQueryService.simpleQueryString(query);}/*** 12、Term=检索（指定字段检索）* 测试：http://localhost:8080/basicmatch/term?query=manning*/@RequestMapping("term")public Response<List<Book>> term(String query) {return basicMatchQueryService.term(query);}/*** 13、Term排序检索-（Term Query - Sorted）* 测试：http://localhost:8080/basicmatch/termsort?query=manning*/@RequestMapping("termsort")public Response<List<Book>> termsort(String query) {return basicMatchQueryService.termsort(query);}/*** 14、范围检索（Range query）* 测试：http://localhost:8080/basicmatch/range?startDate=2015-01-01&endDate=2015-12-31*/@RequestMapping("range")public Response<List<Book>> range(String startDate, String endDate) {return basicMatchQueryService.range(startDate, endDate);}/*** 15. 过滤检索* 测试：http://localhost:8080/basicmatch/filter?query=elasticsearch>e=20*/@RequestMapping("filter")public Response<List<Book>> filter(String query, Integer gte, Integer lte) {return basicMatchQueryService.filter(query, gte, lte);}/*** 17、 Function 得分：Field值因子（ Function Score: Field Value Factor）* 测试：http://localhost:8080/basicmatch/fieldvaluefactor?query=search engine*/@RequestMapping("fieldvaluefactor")public Response<List<Book>> fieldValueFactor(String query) {return basicMatchQueryService.fieldValueFactor(query);}/*** 18、 Function 得分：衰减函数( Function Score: Decay Functions )* 测试：http://localhost:8080/basicmatch/decay?query=search engines&origin=2014-06-15*/@RequestMapping("decay")public Response<List<Book>> decay(String query, @RequestParam(value = "origin", defaultValue = "2014-06-15") String origin) {return basicMatchQueryService.decay(query, origin);}/*** 19、Function得分：脚本得分（ Function Score: Script Scoring ）* 测试：ES需要配置允许groovy脚本运行才可以*/@RequestMapping("script")public Response<List<Book>> script(String query, @RequestParam(value = "threshold", defaultValue = "2015-07-30") String threshold) {return basicMatchQueryService.script(query, threshold);}
}

服务类

@Service
public class BasicMatchQueryService {@Autowiredprivate Client client;@Value("${elasticsearch.bookIndex}")private String bookIndex;@Value("${elasticsearch.bookType}")private String bookType;/*** 进行ES查询，执行请求前后打印出 查询语句 和 查询结果*/private SearchResponse requestGet(String queryName, SearchRequestBuilder requestBuilder) {System.out.println(queryName + " 构建的查询：" + requestBuilder.toString());SearchResponse searchResponse = requestBuilder.get();System.out.println(queryName + " 搜索结果：" + searchResponse.toString());return searchResponse;}...
}

1.1 对 "guide" 执行全文检索 Multi Match Query

    public Response<List<Book>> multiBatch(String query) {MultiMatchQueryBuilder queryBuilder = new MultiMatchQueryBuilder(query);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder);SearchResponse searchResponse = requestGet("multiBatch", requestBuilder);return CommonQueryUtils.buildResponse(searchResponse);}

1.2 在标题字段(title)中搜索带有 "in action" 字样的图书

    public ResponsePage<List<Book>> match(MatchForm form) {MatchQueryBuilder matchQueryBuilder = new MatchQueryBuilder("title", form.getTitle());// 高亮HighlightBuilder highlightBuilder = new HighlightBuilder().field("title").fragmentSize(200);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(matchQueryBuilder).setFrom(form.getFrom()).setSize(form.getSize()).highlighter(highlightBuilder)// 设置 _source 要返回的字段.setFetchSource(Constants.fetchFieldsTSPD, null);...}

多字段检索 (Multi-field Search)

    public Response<List<Book>> multiField(String query) {MultiMatchQueryBuilder queryBuilder = new MultiMatchQueryBuilder(query).field("title").field("summary");SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder);...}

3、 Boosting提升某字段得分的检索( Boosting),将“摘要”字段的得分提高了3倍

    public Response<List<Book>> multiFieldboost(String query) {MultiMatchQueryBuilder queryBuilder = new MultiMatchQueryBuilder(query).field("title").field("summary", 3);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder);...}

4、Bool检索( Bool Query)

    /*** 在标题中搜索一本名为 "Elasticsearch" 或 "Solr" 的书，* AND由 "clinton gormley" 创作，但NOT由 "radu gheorge" 创作*/public Response<List<Book>> bool(BoolForm form) {BoolQueryBuilder boolQuery = new BoolQueryBuilder();// 搜索标题 shouldBoolQueryBuilder shouldTitleBool = new BoolQueryBuilder();form.getShouldTitles().forEach(title -> {shouldTitleBool.should().add(new MatchQueryBuilder("title", title));});boolQuery.must().add(shouldTitleBool);// match 作者form.getMustAuthors().forEach(author -> {boolQuery.must().add(new MatchQueryBuilder("authors", author));});// not match 作者form.getMustNotAuthors().forEach(author -> {boolQuery.mustNot().add(new MatchQueryBuilder("authors", author));});...}

5、 Fuzzy 模糊检索( Fuzzy Queries)

    public Response<List<Book>> fuzzy(String query) {MultiMatchQueryBuilder queryBuilder = new MultiMatchQueryBuilder(query).field("title").field("summary").fuzziness(Fuzziness.AUTO);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSPD, null).setSize(2);...}

6、 Wildcard Query 通配符检索

    /*** 要查找具有以 "t" 字母开头的作者的所有记录*/public Response<List<Book>> wildcard(String fieldName, String pattern) {WildcardQueryBuilder wildcardQueryBuilder = new WildcardQueryBuilder(fieldName, pattern);HighlightBuilder highlightBuilder = new HighlightBuilder().field(Constants.AUTHORS, 200);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(wildcardQueryBuilder).setFetchSource(Constants.fetchFieldsTA, null).highlighter(highlightBuilder);}

7、正则表达式检索( Regexp Query)

    public Response<List<Book>> regexp(String fieldName, String regexp) {RegexpQueryBuilder queryBuilder = new RegexpQueryBuilder(fieldName, regexp);HighlightBuilder highlightBuilder = new HighlightBuilder().field(Constants.AUTHORS);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setQuery(queryBuilder).setTypes(bookType).highlighter(highlightBuilder).setFetchSource(Constants.fetchFieldsTA, null);}

8、匹配短语检索( Match Phrase Query)

    public Response<List<Book>> phrase(String query) {MultiMatchQueryBuilder queryBuilder = new MultiMatchQueryBuilder(query).field(Constants.TITLE).field(Constants.SUMMARY).type(MultiMatchQueryBuilder.Type.PHRASE).slop(3);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSPD, null);}

9、匹配词组前缀检索

    public Response<List<Book>> phrasePrefix(String query) {MatchPhrasePrefixQueryBuilder queryBuilder = new MatchPhrasePrefixQueryBuilder(Constants.SUMMARY, query).slop(3).maxExpansions(10);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSPD, null);}

10、字符串检索（ Query String）

    public Response<List<Book>> queryString(String query) {QueryStringQueryBuilder queryBuilder = new QueryStringQueryBuilder(query);queryBuilder.field(Constants.SUMMARY, 2).field(Constants.TITLE).field(Constants.AUTHORS).field(Constants.PUBLISHER);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSA, null);}

11、简化的字符串检索 （Simple Query String）

    public Response<List<Book>> simpleQueryString(String query) {SimpleQueryStringBuilder queryBuilder = new SimpleQueryStringBuilder(query);queryBuilder.field(Constants.SUMMARY, 2).field(Constants.TITLE).field(Constants.AUTHORS).field(Constants.PUBLISHER);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSA, null).highlighter(Constants.highlightS);}

12、Term/Terms检索（指定字段检索）

    public Response<List<Book>> term(String query) {TermQueryBuilder termQueryBuilder = new TermQueryBuilder(Constants.PUBLISHER, query);// terms 查询/*String[] values = {"manning", "oreilly"};TermsQueryBuilder termsQueryBuilder = new TermsQueryBuilder(Constants.PUBLISHER, values);*/SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(termQueryBuilder).setFetchSource(Constants.fetchFieldsTPPD, null);}

13、Term排序检索-（Term Query - Sorted）

    public Response<List<Book>> termsort(String query) {TermQueryBuilder termQueryBuilder = new TermQueryBuilder(Constants.PUBLISHER, query);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(termQueryBuilder).addSort(Constants.PUBLISHER_KEYWORD, SortOrder.DESC).addSort(Constants.TITLE_KEYWORD, SortOrder.ASC).setFetchSource(Constants.fetchFieldsTPPD, null);}

14、范围检索（Range query）

    public Response<List<Book>> range(String startDate, String endDate) {RangeQueryBuilder queryBuilder = new RangeQueryBuilder(Constants.PUBLISHDATE).gte(startDate).lte(endDate);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTPPD, null);}

15. 过滤检索

    public Response<List<Book>> filter(String query, Integer gte, Integer lte) {BoolQueryBuilder queryBuilder = new BoolQueryBuilder();queryBuilder.must().add(new MultiMatchQueryBuilder(query).field(Constants.TITLE).field(Constants.SUMMARY));if (gte != null || lte != null) {RangeQueryBuilder rangeQueryBuilder = new RangeQueryBuilder(Constants.NUM_REVIEWS);if (gte != null) {rangeQueryBuilder.gte(gte);}if (lte != null) {rangeQueryBuilder.lte(lte);}queryBuilder.filter().add(rangeQueryBuilder);}SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSPN, null);}

17、 Function 得分：Field值因子（ Function Score: Field Value Factor）

    public Response<List<Book>> fieldValueFactor(String query) {// queryMultiMatchQueryBuilder multiMatchQueryBuilder = new MultiMatchQueryBuilder(query).field(Constants.TITLE).field(Constants.SUMMARY);// fieldValueFactorFieldValueFactorFunctionBuilder fieldValueFactor = ScoreFunctionBuilders.fieldValueFactorFunction(Constants.NUM_REVIEWS).factor(2).modifier(FieldValueFactorFunction.Modifier.LOG1P);// functionscoreFunctionScoreQueryBuilder queryBuilder = QueryBuilders.functionScoreQuery(multiMatchQueryBuilder, fieldValueFactor);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSPN, null);}

18、 Function 得分：衰减函数( Function Score: Decay Functions )

    public Response<List<Book>> decay(String query, String origin) {MultiMatchQueryBuilder multiMatchQueryBuilder = new MultiMatchQueryBuilder(query).field(Constants.TITLE).field(Constants.SUMMARY);ExponentialDecayFunctionBuilder exp = ScoreFunctionBuilders.exponentialDecayFunction(Constants.PUBLISHDATE, origin, "30d", "7d");FunctionScoreQueryBuilder queryBuilder = QueryBuilders.functionScoreQuery(multiMatchQueryBuilder, exp).boostMode(CombineFunction.REPLACE);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSPN, null);}

19、Function得分：脚本得分（ Function Score: Script Scoring ）

    public Response<List<Book>> script(String query, String threshold) {MultiMatchQueryBuilder multiMatchQueryBuilder = new MultiMatchQueryBuilder(query).field(Constants.TITLE).field(Constants.SUMMARY);// 参数Map<String, Object> params = new HashMap<>();params.put("threshold", threshold);// 脚本String scriptStr = "publish_date = doc['publish_date'].value; num_reviews = doc['num_reviews'].value; if (publish_date > Date.parse('yyyy-MM-dd', threshold).getTime()) { return log(2.5 + num_reviews) }; return log(1 + num_reviews);";Script script = new Script(ScriptType.INLINE, "painless", scriptStr, params);ScriptScoreFunctionBuilder scriptScoreFunctionBuilder = ScoreFunctionBuilders.scriptFunction(script);FunctionScoreQueryBuilder queryBuilder = QueryBuilders.functionScoreQuery(multiMatchQueryBuilder, scriptScoreFunctionBuilder);SearchRequestBuilder requestBuilder = client.prepareSearch(bookIndex).setTypes(bookType).setQuery(queryBuilder).setFetchSource(Constants.fetchFieldsTSPN, null);}

SearchRequestBuilder常用方法说明

(1) setIndices(String... indices)：上文中描述过，参数可为一个或多个字符串，表示要进行检索的index；(2) setTypes(String... types)：参数可为一个或多个字符串，表示要进行检索的type，当参数为0个或者不调用此方法时，表示查询所有的type；setSearchType(SearchType searchType)：执行检索的类别，值为org.elasticsearch.action.search.SearchType的元素，SearchType是一个枚举类型的类，其值如下所示：QUERY_THEN_FETCH:查询是针对所有的块执行的，但返回的是足够的信息，而不是文档内容（Document）。结果会被排序和分级，基于此，只有相关的块的文档对象会被返回。由于被取到的仅仅是这些，故而返回的hit的大小正好等于指定的size。这对于有许多块的index来说是很便利的（返回结果不会有重复的，因为块被分组了）QUERY_AND_FETCH:最原始（也可能是最快的）实现就是简单的在所有相关的shard上执行检索并返回结果。每个shard返回一定尺寸的结果。由于每个shard已经返回了一定尺寸的hit，这种类型实际上是返回多个shard的一定尺寸的结果给调用者。DFS_QUERY_THEN_FETCH：与QUERY_THEN_FETCH相同，预期一个初始的散射相伴用来为更准确的score计算分配了的term频率。DFS_QUERY_AND_FETCH:与QUERY_AND_FETCH相同，预期一个初始的散射相伴用来为更准确的score计算分配了的term频率。SCAN：在执行了没有进行任何排序的检索时执行浏览。此时将会自动的开始滚动结果集。COUNT：只计算结果的数量，也会执行facet。(4) setSearchType(String searchType)，与setSearchType(SearchType searchType)类似，区别在于其值为字符串型的SearchType，值可为dfs_query_then_fetch、dfsQueryThenFetch、dfs_query_and_fetch、dfsQueryAndFetch、query_then_fetch、queryThenFetch、query_and_fetch或queryAndFetch；(5) setScroll(Scroll scroll)、setScroll(TimeValue keepAlive)和setScroll(String keepAlive)，设置滚动，参数为Scroll时，直接用new Scroll(TimeValue)构造一个Scroll，为TimeValue或String时需要将TimeValue和String转化为Scroll；(6) setTimeout(TimeValue timeout)和setTimeout(String timeout)，设置搜索的超时时间；(7) setQuery，设置查询使用的Query；(8) setFilter，设置过滤器；(9) setMinScore，设置Score的最小数量；(10) setFrom，从哪一个Score开始查；(11) setSize，需要查询出多少条结果；

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