IDEA *** 作ElasticSearch 增删改

IDEA *** 作ElasticSearch 增删改

新建MAVEN工程

导入依赖：

    
    
        org.elasticsearch
        elasticsearch
        6.5.4
    

    
    
        org.elasticsearch.client
        elasticsearch-rest-high-level-client
        6.5.4
    

提供静态方法返回rest高级客户端对象,就能连上ES服务器进行通信：

public class ESClient {
    public static RestHighLevelClient getClient(){
        // 创建HttpHost对象
        HttpHost httpHost = new HttpHost("192.168.200.129",9200);//连接Linux服务器安装的es和ip和端口

        // 创建RestClientBuilder
        RestClientBuilder clientBuilder = RestClient.builder(httpHost);

        // 创建RestHighLevelClient
        RestHighLevelClient client = new RestHighLevelClient(clientBuilder);

        // 返回
        return client;
    }

测试连接问题：

@Test
public void testConnect() {
   RestHighLevelClient client = ESClient.getClient();//.var,org.elasticsearch.client.RestHighLevelClient@61009542
   System.out.println(client);
   System.out.println("测试类调用工具类方法,如果没有报错,表示连上了es服务器");
}

Java *** 作ElasticSearch 索引

API说明Settings.Builder封装了settings中的信息XContentBuilder封装了mapping中的信息CreateIndexRequest封装mapping和settins，index，typeRestHighLevelClientjava访问es服务器的客户端IndicesClient索引的客户端CreateIndexResponse创建完索引后给出响应的对象 创建索引

public class Demo2 {
    RestHighLevelClient client = ESClient.getClient();
    String index = "person";
    String type = "man";

    @Test
    public void createIndex() throws IOException {
        //1. 准备关于索引的settings
        Settings.Builder settings = Settings.builder()
                .put("number_of_shards", 3)
                .put("number_of_replicas", 1);

        //2. 准备关于索引的结构mappings
        XContentBuilder mappings = JsonXContent.contentBuilder()
                .startObject()
                    .startObject("properties")
                        .startObject("name")
                            .field("type","text")
                        .endObject()
                        .startObject("age")
                            .field("type","integer")
                        .endObject()
                        .startObject("birthday")
                            .field("type","date")
                            .field("format","yyyy-MM-dd")
                        .endObject()
                    .endObject()
                .endObject();

        //3. 将settings和mappings封装到一个Request对象
        CreateIndexRequest request = new CreateIndexRequest(index)
                .settings(settings)
                .mapping(type,mappings);

        //4. 通过client对象去连接ES并执行创建索引
        CreateIndexResponse resp = client.indices().create(request, RequestOptions.DEFAULT);

        //5. 输出
        System.out.println("resp:" + resp.toString());
        //resp:org.elasticsearch.action.admin.indices.create.CreateIndexResponse@c4f729f4
    }
}

检查索引是否存在（exists方法）

@Test
public void exists() throws IOException {
    //1. 准备request对象
    GetIndexRequest request = new GetIndexRequest();
    request.indices(index);

    //2. 通过client去 *** 作
    boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);

    //3. 输出
    System.out.println(exists);//索引index存在返回true,不存在返回false
}

删除索引

@Test
public void delete() throws IOException {
    //1. 准备request对象
    DeleteIndexRequest request = new DeleteIndexRequest();
    request.indices(index);

    //2. 通过client对象执行
    AcknowledgedResponse delete = client.indices().delete(request, RequestOptions.DEFAULT);

    //3. 获取返回结果
    System.out.println(delete.isAcknowledged());//true
}

Java *** 作ElasticSearch 文档 添加文档 *** 作

数据通过json数据传输，因此要导入相关依赖方便数据的转换 *** 作：

 com.fasterxml.jackson.core
 jackson-databind
 2.10.3

配置实体类：

public class Person {
 @JsonIgnore//id要忽略转换为json,通过其他Java代码来搞定id生成
 private Integer id;
 private String name;
 private Integer age;
 @JsonFormat(pattern = "yyyy-MM-dd")//转为json时指定格式
 private Date birthday;
}

添加文档数据：

public class Demo3 {
    ObjectMapper mapper = new ObjectMapper();//这里用到上面提供的jackson依赖
    
    RestHighLevelClient client = ESClient.getClient();
    String index = "person";
    String type = "man";

    @Test
    public void createDoc() throws IOException {
        //1. 准备一个json数据
        Person person = new Person(1,"张三",23,new Date());
        String json = mapper.writevalueAsString(person);

        //2. 准备一个request对象(其他Java代码来搞定id生成,即手动指定id↓）
        IndexRequest request = new IndexRequest(index,type,person.getId().toString());
        request.source(json, XContentType.JSON);

        //3. 通过client对象执行添加
        IndexResponse resp = client.index(request, RequestOptions.DEFAULT);

        //4. 输出返回结果
        System.out.println(resp.getResult().toString());
        //添加成功返回的第一次是CREATED,再运行一次是更新是UPDATED
    }
}

修改文档 *** 作

 @Test
public void updateDoc() throws IOException {
    //1. 创建一个Map，指定需要修改的内容
    Map doc = new HashMap();
    doc.put("name","张大三"); // 如果id放在map中会把id属性设置到_source里面
    String docId = "1";

    //2. 创建request对象，封装数据
    UpdateRequest request = new UpdateRequest(index,type,docId);
    request.doc(doc);

    //3. 通过client对象执行
    UpdateResponse update = client.update(request, RequestOptions.DEFAULT);

    //4. 输出返回结果
    System.out.println(update.getResult().toString());//UPDATED
}

删除文档 *** 作

@Test
public void deleteDoc() throws IOException {
    //1. 封装Request对象
    DeleteRequest request = new DeleteRequest(index,type,"1");

    //2. client执行
    DeleteResponse resp = client.delete(request, RequestOptions.DEFAULT);

    //3. 输出结果
    System.out.println(resp.getResult().toString());
    //删除成功返回DELETED,再删没有数据返回NOT_FOUND
}

Java批量 *** 作ElasticSearch 文档（bulk） 批量添加

@Test
public void bulkCreateDoc() throws IOException {
    //1. 准备多个json数据
    Person p1 = new Person(1,"张三",23,new Date());
    Person p2 = new Person(2,"李四",24,new Date());
    Person p3 = new Person(3,"王五",25,new Date());

    String json1 = mapper.writevalueAsString(p1);
    String json2 = mapper.writevalueAsString(p2);
    String json3 = mapper.writevalueAsString(p3);

    //2. 创建Request，将准备好的数据封装进去
    BulkRequest request = new BulkRequest();
    
    request.add(new IndexRequest(index,type,p1.getId().toString()).source(json1,XContentType.JSON));
    
    request.add(new IndexRequest(index,type,p2.getId().toString()).source(json2,XContentType.JSON));
    request.add(new IndexRequest(index,type,p3.getId().toString()).source(json3,XContentType.JSON));

    //3. 用client执行
    BulkResponse resp = client.bulk(request, RequestOptions.DEFAULT);

    //4. 输出结果
    System.out.println(resp.toString());//org.elasticsearch.action.bulk.BulkResponse@3aa078fd
}

批量删除

@Test
public void bulkDeleteDoc() throws IOException {
    //1. 封装Request对象
    BulkRequest request = new BulkRequest();
    
    request.add(new DeleteRequest(index,type,"1"));
    request.add(new DeleteRequest(index,type,"2"));
    request.add(new DeleteRequest(index,type,"3"));

    //2. client执行
    BulkResponse resp = client.bulk(request, RequestOptions.DEFAULT);

    //3. 输出
    System.out.println(resp);//org.elasticsearch.action.bulk.BulkResponse@196a42c3
}