全文检索的应用越来越广泛，几乎成了互联网应用的标配，商品搜索、日志分析、历史数据归档等等，各种场景都会涉及到大批量的数据，在全文检索方面，方案无外乎Lucene、Solr、Elasticsearch三种应用的较为广泛。es、solr的底层都依托于Lucene，但es比solr学习成本更低，由于其提供的RESTful API简单快捷，对互联网应用开发而言更是如虎添翼。
下面结合以实际案例，通过Java API的形式操作es数据集。
框架选型基础是Spring Boot + Spring-data-elasticsearch + elasticsearch。
使用ElasticsearchRepository的形式来连接、维护ES数据集，ElasticsearchRepository中提供了简单的操作索引数据的方法集合，继承自ElasticsearchCrudRepository，涵盖了CRUD、排序、分页等常见的基本操作功能。
@NoRepositoryBeanpublic interface ElasticsearchRepository<T, ID extends Serializable> extends ElasticsearchCrudRepository<T, ID> {<S extends T> S index(S var1);Iterable<T> search(QueryBuilder var1);Page<T> search(QueryBuilder var1, Pageable var2);Page<T> search(SearchQuery var1);Page<T> searchSimilar(T var1, String[] var2, Pageable var3);void refresh();Class<T> getEntityClass();}
从基本的pom配置开始
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.esp.index.data</groupId><artifactId>esp-cube</artifactId><version>0.0.1-SNAPSHOT</version><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>1.5.2.RELEASE</version><relativePath /> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.7</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId><exclusions><exclusion><groupId>org.apache.tomcat</groupId><artifactId>tomcat-jdbc</artifactId></exclusion></exclusions></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-elasticsearch</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><exclusions><exclusion><artifactId>log4j-over-slf4j</artifactId><groupId>org.slf4j</groupId></exclusion></exclusions></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-logging</artifactId></exclusion></exclusions></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-log4j</artifactId><version>1.3.1.RELEASE</version></dependency></dependencies><build><finalName>esp-cube</finalName><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>
编写自己的Resository操作类
public interface ArticleSearchRepository extends ElasticsearchRepository<Article, Long>{List<Article> findByAbstractsAndContent(String abstracts, String content);}
其中Article为是与elasticsearch连接的实体类，类似于PO的概念，其中指定的索引名称、类型名称、及分片、副本数量等要素。
@Data@Document(indexName = "article_index", type = "article", shards = 5, replicas = 1, indexStoreType = "fs", refreshInterval = "-1")public class Article implements Serializable {/*** serialVersionUID:** @since JDK 1.6*/private static final long serialVersionUID = 1L;@Idprivate Long id;/** 标题 */private String title;/** 摘要 */private String abstracts;/** 内容 */private String content;/** 发表时间 */@Field(format = DateFormat.date_time, index = FieldIndex.no, store = true, type = FieldType.Object)private Date postTime;/** 点击率 */private Long clickCount;}
我们需要定义域的实体和一个Spring data的基本的CRUD支持库类。用id注释定义标识符字段，如果你没有指定ID字段，Elasticsearch不能索引你的文件。同时需要指定索引名称类型，@Document注解也有助于我们设置分片和副本数量。
接口类
public interface ArticleService {/*** saveArticle: 写入<br/>** @author guooo Date:2017年9月27日下午3:20:06* @param article* @return* @since JDK 1.6*/long saveArticle(Article article);/*** deleteArticle: 删除，并未真正删除，只是查询不到<br/>** @author guooo Date:2017年9月27日下午3:20:08* @param id* @since JDK 1.6*/void deleteArticle(long id);/*** findArticle: <br/>** @author guooo Date:2017年9月27日下午3:20:10* @param id* @return* @since JDK 1.6*/Article findArticle(long id);/*** findArticlePageable: <br/>** @author guooo Date:2017年9月27日下午3:20:13* @return* @since JDK 1.6*/List<Article> findArticlePageable();/*** findArticleAll: <br/>** @author guooo Date:2017年9月27日下午3:20:15* @return* @since JDK 1.6*/List<Article> findArticleAll();/*** findArticleSort: <br/>** @author guooo Date:2017年9月27日下午3:20:18* @return* @since JDK 1.6*/List<Article> findArticleSort();/*** search: <br/>** @author guooo Date:2017年9月27日下午3:20:22* @param content* @return* @since JDK 1.6*/List<Article> search(String content);/*** update: es没有修改操作，结合save操作完成<br/>** @author guooo Date:2017年9月27日下午3:20:25* @param id* @return* @since JDK 1.6*/long update(long id);}
接口实现
@Servicepublic class ArticleServiceImpl implements ArticleService {final int page = 0;final int size = 10;/* 搜索模式 */String SCORE_MODE_SUM = "sum"; // 权重分求和模式Float MIN_SCORE = 10.0F; // 由于无相关性的分值默认为 1 ，设置权重分最小值为 10Pageable pageable = new PageRequest(page, size);@AutowiredArticleSearchRepository repository;@Overridepublic long saveArticle(Article article) {Article result = repository.save(article);return result.getId();}@Overridepublic void deleteArticle(long id) {repository.delete(id);}@Overridepublic Article findArticle(long id) {return repository.findOne(id);}@Overridepublic List<Article> findArticlePageable() {return repository.findAll(pageable).getContent();}@Overridepublic List<Article> findArticleAll() {Iterable<Article> iterables = repository.findAll();List<Article> articles = new ArrayList<>();for (Article article : iterables) {articles.add(article);}return articles;}@Overridepublic List<Article> findArticleSort() {List<Order> orders = new ArrayList<>();Order order = new Order(Direction.ASC, "clickCount");orders.add(order);Sort sort = new Sort(orders);Iterable<Article> iterables = repository.findAll(sort);List<Article> articles = new ArrayList<>();for (Article article : iterables) {articles.add(article);}return articles;}@Overridepublic List<Article> search(String content) {return repository.findByAbstractsAndContent(content, content);}@Overridepublic long update(long id) {Article article = repository.findOne(id);article.setTitle("test");Article retun = repository.save(article);System.out.println(retun.getId()+"更新的数据");return retun.getId();}}
是不是与JPA、hibernate操作数据集的手法很类似？
controller方法类：
@RestController@RequestMapping(value = "/article")public class APIArticleController {@AutowiredArticleService articleService;@RequestMapping(value = "save", method = RequestMethod.POST)public long save() {for (int i = 10000; i < 12000; i++) {Article article = new Article();article.setClickCount(Long.valueOf(i + RandomUtils.nextInt(23, i)));article.setAbstracts("我的一个测试" + i);article.setContent(i + "这是第一个测试的内容@spring-data-elasticsearch");article.setPostTime(new Date());article.setId(Long.valueOf(RandomUtils.nextLong(i, i)));long _id = articleService.saveArticle(article);System.out.println(_id);}return 23;}@RequestMapping(value = "delete", method = RequestMethod.POST)public void deleteArticle(long id) {articleService.deleteArticle(id);}@RequestMapping(value = "findOne", method = RequestMethod.POST)public Article findArticle(long id) {return articleService.findArticle(id);}@RequestMapping(value = "findArticlePageable", method = RequestMethod.POST)public List<Article> findArticlePageable() {return articleService.findArticlePageable();}@RequestMapping(value = "findArticleAll", method = RequestMethod.POST)public List<Article> findArticleAll() {return articleService.findArticleAll();}@RequestMapping(value = "findArticleSort", method = RequestMethod.POST)public List<Article> findArticleSort() {return articleService.findArticleSort();}@RequestMapping(value = "search", method = RequestMethod.POST)public List<Article> search(String content) {return articleService.search(content);}@RequestMapping(value = "update", method = RequestMethod.POST)public long update(long id) {return articleService.update(id);}}
Spring Boot的启动类及配置项，这里略过，项目启动后，可能过controller暴露出来的方法进行Article数据索引的CRUD操作