spring-data-elasticsearch + java 查询方法的封装

• 最近开始重构elasicsearch+springboot+spring data elasticsearch的东西

• 由于近期更新了elasticsearch 5.x /6.x,大家都忙着尝鲜，不过其中整合框架的过程中遇到了很多的问题

• 在复写项目的过程中，有重新温习了一下spring data elasticsearch 的操作，我当前尝试的是spring-data-elasticsearch 3.0.1.RELEASE版本，比对以前的一些操作修改的不多，就是一些save=>saveAll,findOne=>findById,findAll=>findAllByIds等等，底层的操作原理没有影响，如果会的同志应当不会太困扰
• 后期还会对transportClient的使用和框架整合ES的searchquery的介绍

以下是旧版本的spring-data-elasticsearch +java的操作：

1、封装数据库基本CRUD(创建（Create）、更新（Update）、读取（Retrieve）和删除（Delete）)

public interface CrudRepository<T, ID extends Serializable> extends Repository<T, ID> { <S extends T> S save(S entity); T findOne(ID primaryKey);     Iterable<T> findAll();      Long count();           void delete(T entity);      boolean exists(ID primaryKey);  // … more functionality omitted.}

2、分页排序查询

public interface PagingAndSortingRepository<T, ID extends Serializable> extends CrudRepository<T, ID> { Iterable<T> findAll(Sort sort); Page<T> findAll(Pageable pageable);}//Accessing the second page by a page size of 20PagingAndSortingRepository<User, Long> repository = // … get access to a beanPage<User> users = repository.findAll(new PageRequest(1, 20));

3、计数

public interface UserRepository extends CrudRepository<User, Long> { Long countByLastname(String lastname);}

4、删除

public interface UserRepository extends CrudRepository<User, Long> { Long deleteByLastname(String lastname); List<User> removeByLastname(String lastname);}

5、自定义查询方法自动注入
声明一个接口继承Repository

interface PersonRepository extends Repository<Person, Long> {List<Person> findByLastname(String lastname);}

保证注入了elasticsearch配置
在bootstrap.yml中写入了spring-data-elasticsearch的配置文件将自动注入
注入调用

public class SomeClient { @Autowired private PersonRepository repository; public void doSomething() {  List<Person> persons = repository.findByLastname("Matthews"); }}

6、支持Java8 Stream查询和sql语句查询

@Query("select u from User u")Stream<User> findAllByCustomQueryAndStream();Stream<User> readAllByFirstnameNotNull();@Query("select u from User u")Stream<User> streamAllPaged(Pageable pageable);try (Stream<User> stream = repository.findAllByCustomQueryAndStream()) { stream.forEach(…);}

7、支持异步查询

@AsyncFuture<User> findByFirstname(String firstname);        @AsyncCompletableFuture<User> findOneByFirstname(String firstname);@AsyncListenableFuture<User> findOneByLastname(String lastname);

支持原生es JavaAPI

1、NativeSearchQueryBuilder构建查询

@Autowiredprivate ElasticsearchTemplate elasticsearchTemplate;SearchQuery searchQuery = new NativeSearchQueryBuilder()  .withQuery(matchAllQuery())  .withFilter(boolFilter().must(termFilter("id", documentId)))  .build();Page<SampleEntity> sampleEntities =  elasticsearchTemplate.queryForPage(searchQuery,SampleEntity.class);

2、利用Scan和Scroll进行大结果集查询

SearchQuery searchQuery = new NativeSearchQueryBuilder()  .withQuery(matchAllQuery())  .withIndices("test-index")  .withTypes("test-type")  .withPageable(new PageRequest(0,1))  .build();String scrollId = elasticsearchTemplate.scan(searchQuery,1000,false);List<SampleEntity> sampleEntities = new ArrayList<SampleEntity>();boolean hasRecords = true;while (hasRecords){  Page<SampleEntity> page = elasticsearchTemplate.scroll(scrollId, 5000L , new ResultsMapper<SampleEntity>()  {    @Override    public Page<SampleEntity> mapResults(SearchResponse response) {      List<SampleEntity> chunk = new ArrayList<SampleEntity>();      for(SearchHit searchHit : response.getHits()){        if(response.getHits().getHits().length <= 0) {          return null;        }        SampleEntity user = new SampleEntity();        user.setId(searchHit.getId());        user.setMessage((String)searchHit.getSource().get("message"));        chunk.add(user);      }      return new PageImpl<SampleEntity>(chunk);    }  });  if(page != null) {    sampleEntities.addAll(page.getContent());    hasRecords = page.hasNextPage();  }  else{    hasRecords = false;  }  }}

3、获取client实例进行节点操作,可以自行封装Util方法

@Autowiredprivate ElasticsearchTemplate elasticsearchTemplate;public void searchHelper() throws IOException {    //节点客户端    // on startup//    Node node = nodeBuilder().clusterName("syncwt-es").client(true).node();//    Client nodeClient = node.client();    //传输客户端//    Settings settings = Settings.settingsBuilder().build();//    Client transportClient = TransportClient.builder().settings(settings).build();    Client transportClient = elasticsearchTemplate.getClient();    Customer customer = new Customer("Alice", "Smith");    // instance a json mapper    ObjectMapper mapper = new ObjectMapper(); // create once, reuse    // generate json    String json = mapper.writeValueAsString(customer);    System.out.println("--------------------------------jackson mapper");    System.out.println(json);    XContentBuilder builder = jsonBuilder()        .startObject()        .field("firstName", "Alice")        .field("latName", "Smith")        .endObject();    System.out.println("--------------------------------jsonBuilder");    System.out.println(builder.string());    IndexResponse response = transportClient.prepareIndex("es-customer", "customer")        .setSource(jsonBuilder()            .startObject()            .field("firstName", "Alice")            .field("latName", "Smith")            .endObject()        )        .execute()        .actionGet();    System.out.println("--------------------------------response");    System.out.println(response.toString());    // on shutdown//    node.close();//    nodeClient.close();    transportClient.close();  }