浅谈SpringDataElasticSearch

　　Spring Data
　　Spring Data 帮助我们避免了一些样板式代码，比如我们要定义一个接口，可以直接继承接口ElasticSearchRepository接口，这样Spring Data就帮助我们实现了操作documents基础的CURD方法，在ES里index类似RDBMS里table的概念，documents类似table里datarow的概念，所以ElasticSearchRepository默认已经帮我们实现了操作documents的方法。 类似Spring Data JPA，我们也可以根据约定实现自己想要的方法。Maven dependency    org.springframework.boot    spring-boot-starter-data-elasticsearch 配置映射
　　这里在实体类Product上使用了Document注解，配置了index名称，index就相当于一张表。@Document(indexName = ＂productindex＂) public class Product {     @Id     private String id;      @Field(type = FieldType.Text, name = ＂name＂)     private String name;      @Field(type = FieldType.Double, name = ＂price＂)     private Double price;      @Field(type = FieldType.Integer, name = ＂quantity＂)     private Integer quantity;      @Field(type = FieldType.Keyword, name = ＂category＂)     private String category;      @Field(type = FieldType.Keyword, name = ＂desc＂)     private String description;      @Field(type = FieldType.Date, name = ＂createdDateTime＂)     private LocalDate createdDateTime;      @Field(type = FieldType.Nested, includeInParent = true)     private List authors; }定义接口public interface ProductRepository extends ElasticsearchRepository {     Product findByName(String name);      Page findByName(String name, PageRequest pageRequest);          Page findByNameContaining(String name, PageRequest pageRequest); }java 配置@Configuration @EnableElasticsearchRepositories(basePackages = ＂com.shanxi.springbootes.repository＂) @ComponentScan(basePackages = {＂com.shanxi.springbootes＂}) public class ElasticSearchConfig extends AbstractElasticsearchConfiguration {      @Override     @Bean     public RestHighLevelClient elasticsearchClient() {         ClientConfiguration config = ClientConfiguration                 .builder()                 .connectedTo(＂localhost:9200＂)                 .build();          return RestClients.create(config).rest();     }      @Bean     public ElasticsearchRestTemplate elasticsearchRestTemplate(){         return new ElasticsearchRestTemplate(elasticsearchClient());     } }创建index和documents
　　Spring Data ElasticSearch默认已经自动帮助我们创建index，我们也可以手动通过程序创建index。创建和删除index//创建index this.elasticsearchRestTemplate.indexOps(Product.class).create();  //删除index this.elasticsearchRestTemplate.indexOps(Product.class).delete(); 创建documents @Test  public void it_should_create_product_documents_successful(){      List products = new ArrayList<>();       for(int i =1;i<=30;i++){             Product product =new Product();              product.setName(＂python＂+i)                     .setPrice(30d)                     .setQuantity(10)                     .setCategory(＂book＂+i)                     .setDescription(＂a nice book＂+i)                     .setCreatedDateTime(LocalDate.now())             ;              product.setAuthors(Arrays.asList(new Author(＂李雷＂),new Author(＂韩梅梅＂)));              products.add(product);      }       this.productRepository.saveAll(products);      Assertions.assertEquals(products.size(),30); }编辑documents @Test  public void it_should_update_Product_successful(){     Product product =  this.productRepository.findByName(＂python1＂);     product.setQuantity(15);      this.productRepository.save(product);      Assertions.assertEquals(15, product.getQuantity());   }删除documents@Test public void it_should_delete_Product_successful(){     Product product = this.productRepository.findById(＂ygnG3n4B9LwueG0uoDc2＂).get();     this.productRepository.delete(product); }查询documents精确查询 @Test  public void it_should_call_findBy_successful(){     Product product = this.productRepository.findByName(＂python2＂);      Assertions.assertEquals(product.getQuantity(),10);     Assertions.assertEquals(product.getPrice(),30d);  }匹配查询
　　这个方法使用Name模糊查询，并且支持分页。@Test public void it_should_call_findByNameContaining_success(){     Page page = this.productRepository.findByNameContaining(＂python＂, PageRequest.of(1,10));     for (Product product : page.toList()) {         System.out.println(product.toString());     }      Assertions.assertEquals(page.toList().size(),10); }