ES_API操作

悠悠 2022-11-02 13:18 208阅读 0赞

# ES\_API读写操作 #

新建工程并导入依赖：

<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.5</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.3.6</version>
    </dependency>
    
    <dependency>
        <groupId>io.searchbox</groupId>
        <artifactId>jest</artifactId>
        <version>5.3.3</version>
    </dependency>
    
    <dependency>
        <groupId>net.java.dev.jna</groupId>
        <artifactId>jna</artifactId>
        <version>4.5.2</version>
    </dependency>
    
    <dependency>
        <groupId>org.codehaus.janino</groupId>
        <artifactId>commons-compiler</artifactId>
        <version>2.7.8</version>
    </dependency>
    
    <dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>6.6.0</version>
    </dependency>

## 1. 写数据 ##

1）单条数据写入

//1.创建ES客户端构建器
            JestClientFactory factory = new JestClientFactory();
    
            //2.创建ES客户端连接地址
            HttpClientConfig httpClientConfig = new HttpClientConfig.Builder("http://hadoop102:9200").build();
    
            //3.设置ES连接地址
            factory.setHttpClientConfig(httpClientConfig);
    
            //4.获取ES客户端连接
            JestClient jestClient = factory.getObject();
    
            //5.构建ES插入数据对象
            Index index = new Index.Builder("{\n" +
                    " \"id\":\"1002\",\n" +
                    " \"movie_name\":\”姜子牙\”\n" +
                    "}").index("movie_test1").type("_doc").id("1002").build();
    
            //6.执行插入数据操作
            jestClient.execute(index);
    
            //7.关闭连接
            jestClient.shutdownClient();

使用bean对象的方式插入数据

//5.构建ES插入数据对象
     		MovieInfo movieInfo = new MovieInfo(1004, "《阿甘正传》");
    
            //Index代表对一行记录的插入操作 PUT /index/type/id {}
            Index index = new Index.Builder(movieInfo)
                    .index("movie_test1")
                    .type("_doc")
                    .id("1003")
                    .build();
    
           //6.执行插入数据操作
           jestClient.execute(index);

创建movie的bean对象

import lombok.*;
    
    @Getter
    @Setter
    @NoArgsConstructor
    @AllArgsConstructor
    @ToString
    public class MovieInfo { 
        private Integer id;
        private String name;
    }

## 2. 批量数据写入 ##

public class WriteBulk { 
    
        public static void main(String[] args) throws IOException { 
    
            //1.创建客户端对象
            JestClientFactory clientFactory = new JestClientFactory();
    
            //2.设置连接参数
            HttpClientConfig clientConfig = new HttpClientConfig.Builder("http://hadoop102:9200").build();
    
            clientFactory.setHttpClientConfig(clientConfig);
    
            //3.从JestClientFactory中获取一个ES的客户端对象
            JestClient client = clientFactory.getObject();
    
            //4.批量数据准备（可以在一个批次中向多个表插入数据）
            MovieInfo movieInfo = new MovieInfo(1007, "《心灵奇旅》");
    
            Employee employee = new Employee(1200, "Mike", "eat", '男', 3000.0, 30);
    
            //5.构建ES插入数据对象
            //Index代表对一行记录的插入操作 PUT /index/type/id {}
            Index index = new Index.Builder(movieInfo)
                    .index("move_index1")
                    .type("movie_type")
                    .id("4")
                    .build();
            Index index2 = new Index.Builder(employee)
                    .index("test")
                    .type("emps")
                    .id("20")
                    .build();
            Delete delete = new Delete.Builder("3")
                    .index("move_index1")
                    .type("movie_type")
                    .build();
    
            Bulk bulk = new Bulk.Builder()
                    .addAction(index)
                    .addAction(index2)
                    .addAction(delete)
                    .build();
            //.defaultIndex().defaultType() 当前批量操作都是向一个表，在bulk中放入的每个 Action对象，{action:{metadata}}
    
            
            //6.调用客户端提供的API进行插入数据操作
            client.execute(bulk);
    
            //7.关闭连接
            client.shutdownClient();
    
        }

## 3. 读数据 ##

public static void main(String[] args) throws IOException { 
    
            //1.创建ES客户端连接池
            JestClientFactory clientFactory = new JestClientFactory();
    
            //2.设置连接的集群地址参数
            HttpClientConfig clientConfig = new HttpClientConfig.Builder("http://hadoop102:9200").build();
    
            //3.设置ES连接地址
            clientFactory.setHttpClientConfig(clientConfig);
    
            //4.从JestClientFactory中获取一个ES的客户端对象
            JestClient client = clientFactory.getObject();
    
            //5.构建查询数据对象
            String requestBody="{\n" +
                    " \"query\": {\n" +
                    " \"match\": {\n" +
                    " \"hobby\": \"购物\"\n" +
                    " }\n" +
                    " },\n" +
                    " \"aggs\": {\n" +
                    " \"gendercount\": {\n" +
                    " \"terms\": {\n" +
                    " \"field\": \"gender.keyword\",\n" +
                    " \"size\": 10\n" +
                    " },\n" +
                    " \"aggs\": {\n" +
                    " \"avgage\": {\n" +
                    " \"avg\": {\n" +
                    " \"field\": \"age\"\n" +
                    " }\n" +
                    " }\n" +
                    " }\n" +
                    " }\n" +
                    " }\n" +
                    "}";
            //GET /index/type
            Search search = new Search.Builder(requestBody)
                    .addIndex("test")
                    .addType("emps")
                    .build();
    
            
            //6.执行查询操作
            SearchResult result = client.execute(search);
    
            //7.解析查询结果
            //取出total和maxScore
            System.out.println(result.getTotal());
            System.out.println(result.getMaxScore());
    
            //取出命中的记录
            List<SearchResult.Hit<Employee, Void>> hits = result.getHits(Employee.class);
    
            for (SearchResult.Hit<Employee, Void> hit : hits) { 
                //获取 _source
                System.out.println(hit.source);
            }
    
            //获取聚合的结果
            MetricAggregation aggregations = result.getAggregations();
    
            //根据聚合的字段名称取出结果
            TermsAggregation gendercount = aggregations.getTermsAggregation("gendercount");
    
            //聚合的数据存放在bulks
            List<TermsAggregation.Entry> buckets = gendercount.getBuckets();
    
            for (TermsAggregation.Entry bucket : buckets) { 
                //dou_count: getCount()
                System.out.println(bucket.getKey() +" "+bucket.getCount()
                    +" "+bucket.getAvgAggregation("avgage").getAvg());
            }
    
    
            //8.关闭连接
            client.shutdownClient();
    
        }

简化：使用api构造查询的请求体

public static void main(String[] args) throws IOException { 
    
            //1.创建ES客户端连接池
        
            //2.设置连接的集群地址参数
          
            //3.设置ES连接地址
    
            //4.从JestClientFactory中获取一个ES的客户端对象
           
             //5.构建查询数据对象
             /* 使用api构造查询的请求体 SearchSourceBuilder: 可以构造一个Search中的_source对象，构造json串 QueryBuilder: 封装了Query{} 中的所有的信息，需要根据查询的类型来构造不同的QueryBuilder AggregationBuilder: 封装了 aggs{} 中的所有的信息,通过AggregationBuilders根据聚合的类型来构造 */
            TermsAggregationBuilder aggregationBuilder = AggregationBuilders.terms("gendercount")
                    .field("gender.keyword")
                    .size(10)
                    .subAggregation(AggregationBuilders.avg("avgage").field("age"));
    
            MatchQueryBuilder matchQueryBuilder = new MatchQueryBuilder("hobby", "购物");
    
            SearchSourceBuilder searchBuilder = new SearchSourceBuilder()
                    .query(matchQueryBuilder)
                    .aggregation(aggregationBuilder);
    
            //GET /index/type
            Search search = new Search.Builder(searchBuilder.toString())
                    .addIndex("test")
                    .addType("emps")
                    .build();
    
            
            
    		//6.执行查询操作
            SearchResult result = client.execute(search);
    
            //7.解析查询结果
           
            //8.关闭连接
            client.shutdownClient();
    
        }