Java如何操作Elasticsearch

前言

Procuct实体类

一、操作索引

二、操作文档

本文文章介绍的是通过template的方法操作elasticsearch，他的话直接本地注入使用就行，repository方法还需要实现接口，所以我个人喜欢template（他还支持复杂查询嘞！）

前言

Procuct实体类

java 复制代码

@Document(indexName = "product",createIndex = true)
@Data
@AllArgsConstructor
public class Product {
    @Id
    @Field(type = FieldType.Integer,store = true,index = true)
    private Integer id;
    @Field(type = FieldType.Text,store = true,index = true,analyzer = "ik_max_word",searchAnalyzer = "ik_max_word")
    private String productName;
    @Field(type = FieldType.Text,store = true,index = true,analyzer = "ik_max_word",searchAnalyzer = "ik_max_word")
    private String productDesc;
}

一、操作索引

java 复制代码

@SpringBootTest
public class TemplateTest {
  @Autowired
  private ElasticsearchTemplate template;


  // 新增索引
  @Test
  public void addIndex() {
    // 获得索引操作对象
    IndexOperations indexOperations = template.indexOps(Product.class);
    // 创建索引,注：该方法无法设置索引结构，不推荐使用
    indexOperations.create();
   }


  // 删除索引
  @Test
  public void delIndex() {
    // 获得索引操作对象
    IndexOperations indexOperations = template.indexOps(Product.class);
    // 删除索引
    indexOperations.delete();
   }
}

不过一般我们创建索引在实体类创建时就创建或者是在kibna中自己创建就行！

二、操作文档

java 复制代码

// 新增/修改文档
@Test
public void addDocument() {
  Product product = new Product(7, "es1", "es是一款优秀的搜索引擎");
  template.save(product);
}


// 删除文档
@Test
public void delDocument() {
  template.delete("7", Product.class);
}


// 根据id查询
@Test
public void findAllDocument() {
  Product product = template.get("1", Product.class);
  System.out.println(product);
}

三、查询文档

template的search方法可以查询文档
java 复制代码
SearchHits<T> search(Query query, Class<T> clazz)：查询文档，query是查询条件对象，clazz是结果类型。

java 复制代码

// 查询文档2
@Test
public void searchDocument2() {
  String productName = "三体";
  String productDesc = "优秀";


  // 1.构建查询条件
  NativeQuery query=new NativeQueryBuilder()
                .withQuery(Queries.matchAllQueryAsQuery())
                .build();
 


  // 2.查询
  SearchHits<Product> result = template.search(query, Product.class);
  // 3.处理查询结果
  for (SearchHit<Product> productSearchHit : result) {
    Product product = productSearchHit.getContent();
    System.out.println(product);
   }
}

四、复杂条件查询

java 复制代码

// 复杂查询
@Test
public void searchDocument2(){
  String productName = "三体";
  String productDesc = "优秀";


  // 1.构造查询条件
  NativeQueryBuilder nativeQueryBuilder = new NativeQueryBuilder();
  // 如果没有传入参数，查询所有
  if (productName == null && productDesc == null){
    nativeQueryBuilder.withQuery(Queries.matchAllQueryAsQuery());
   }else {
    BoolQuery.Builder boolQuery = QueryBuilders.bool();
    if (productName != null){
      boolQuery.must(Queries.matchQueryAsQuery("productName",productName,null,null));
     }
    if (productDesc != null){
      boolQuery.must(Queries.matchQueryAsQuery("productDesc",productDesc,null,null));
     }
    nativeQueryBuilder.withQuery(boolQuery.build()._toQuery());
   }
  NativeQuery query = nativeQueryBuilder.build();


  // 2.查询
  SearchHits<Product> result = template.search(query, Product.class);
  // 3.处理查询结果
  for (SearchHit<Product> productSearchHit : result) {
    Product product = productSearchHit.getContent();
    System.out.println(product);
   }
}

五、分页查询

java 复制代码

// 分页查询文档
@Test
public void searchDocumentPage() {


  // 1.构建查询条件
  Pageable pageable = PageRequest.of(0, 3);
  NativeQuery query = new NativeQueryBuilder()
     .withQuery(Queries.matchAllQueryAsQuery())
     .withPageable(pageable)
     .build();
  // 2.查询
  SearchHits<Product> result = template.search(query, Product.class);


  // 3.处理查询结果
  List<Product> content = new ArrayList();
  for (SearchHit<Product> productSearchHit : result) {
    Product product = productSearchHit.getContent();
    content.add(product);
   }


  /**
     * 封装Page对象，参数1：具体数据，参数2：分页条件对象，参数3：总条数
     */
  Page<Product> page = new PageImpl(content, pageable, result.getTotalHits());


  System.out.println(page.getTotalElements());
  System.out.println(page.getTotalPages());
  System.out.println(page.getContent());
}

六、结果排序

java 复制代码

// 结果排序
@Test
public void searchDocumentSort() {
  // 1.构建查询条件
  NativeQuery query = new NativeQueryBuilder()
     .withQuery(Queries.matchAllQueryAsQuery())
     .withSort(Sort.by(Sort.Direction.DESC, "id"))
     .build();
  // 2.查询
  SearchHits<Product> result = template.search(query, Product.class);


  // 3.处理查询结果
  for (SearchHit<Product> productSearchHit : result) {
    Product product = productSearchHit.getContent();
    System.out.println(product);
   }
}