ElasticSearch集成SpringBoot

ES是一个**开源的高扩展的分布式全文搜索引擎,**是整个Elastic Stack技术栈的核心。它可以近乎实时的存储、检索数据;本身扩展性很好,可以扩展到上百台服务器,处理PB级别的数据。Elasticsearch软件是由Java语言开发的,所以也可以通过Java API的方式对Elasticsearch服务进行访问,并且操作的方式基本和Http操作一致

本文已经收录到我的Github: github.com/chenliang15…

Maven依赖

  • pom.xml中加入ES需要的依赖

    <dependencies>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.8.0</version>
        </dependency>
        <!-- elasticsearch的客户端 -->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.8.0</version>
        </dependency>
        <!-- elasticsearch依赖2.x的log4j -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.8.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.8.2</version>
    </dependency>
    	<dependency>
    		<groupId>com.fasterxml.jackson.core</groupId>
    		<artifactId>jackson-databind</artifactId>
    		<version>2.9.9</version>
    	</dependency>
        <!-- junit单元测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
    复制代码
  • 如果在运行时报错

    java.lang.NoSuchMethodError: org.elasticsearch.client.Request.addParameters
    复制代码

    那么应该是发生了依赖冲突,新建一个Maven项目,最好不要直接创建springboot项目,可能会有依赖冲突,将上面的依赖加入到maven项目的pom中

链接ES客户端

因为使用的highLevel的ES客户端,所以可以很方便的连接到ES,只需要通过host和port就可以直接连接

public static void main(String[] args) throws IOException {
    RestHighLevelClient esClient = new RestHighLevelClient(
        RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );

    esClient.close();
}
复制代码

如果代码执行正常,没有报错那么就表示正常连接到了ES节点,可以通过获取到的RestHighLevelClient对象进行操作

索引操作

加入了maven依赖,那么就可以通过Java客户端链接到ES进行操作,首先进行索引的基本操作

  • 创建索引

    RestHighLevelClient esClient = new RestHighLevelClient(
        RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    @Test
    public void index_create() throws IOException {
        // 创建索引 - 请求对象
        CreateIndexRequest request = new CreateIndexRequest("test");
        // 发送请求,获取响应
        CreateIndexResponse response = esClient.indices().create(request, RequestOptions.DEFAULT);
        boolean acknowledged = response.isAcknowledged();
        // 响应状态
        System.out.println("操作状态 = " + acknowledged);
    }
    复制代码
  • 查询索引

    RestHighLevelClient esClient = new RestHighLevelClient(
        RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    @Test
    public void index_get() throws IOException {
    
        GetIndexRequest request = new GetIndexRequest("test");
    
        GetIndexResponse response = esClient.indices().get(request, RequestOptions.DEFAULT);
    
        System.out.println(Arrays.toString(response.getIndices()));
        System.out.println(response.getMappings());
        System.out.println(response.getSettings());
    }
    复制代码
  • 删除索引

    RestHighLevelClient esClient = new RestHighLevelClient(
        RestClient.builder(new HttpHost("localhost", 9200, "http"))
    );
    
    @Test
    public void index_delete() throws IOException {
    
        DeleteIndexRequest request = new DeleteIndexRequest("test");
    
        AcknowledgedResponse response = esClient.indices().delete(request, RequestOptions.DEFAULT);
    
        System.out.println(response.isAcknowledged());
    }
    复制代码

文档操作

文档作为数据的对象,可以通过ES的客户端对象直接操作

RestHighLevelClient对象和上面的创建方式相同,此处省略

文档基本操作
  • 创建文档

    @Test
    public void doc_create() throws IOException {
        IndexRequest request = new IndexRequest();
        // 设置操作的索引和当前插入的文档的id
        request.index("people").id("1001");
    
        User user = new User();
        user.setName("张三");
        user.setAge(10);
        user.setSex("男");
    
        ObjectMapper mapper = new ObjectMapper();
        String userJson = mapper.writeValueAsString(user);
    
        request.source(userJson, XContentType.JSON);
    
        IndexResponse response = esClient.index(request, RequestOptions.DEFAULT);
    
        System.out.println(response);
    
        System.out.println("_index" + response.getIndex());
        System.out.println("_id" + response.getId());
        System.out.println("_result" + response.getResult());
    }
    复制代码
  • 更新文档

    @Test
    public void doc_update() throws IOException {
        UpdateRequest request = new UpdateRequest();
        request.index("people").id("1001");
    
        request.doc(XContentType.JSON, "sex", "女");
    
        UpdateResponse response = esClient.update(request, RequestOptions.DEFAULT);
    
        System.out.println(response);
    }
    复制代码
  • 查询文档

    @Test
    public void doc_get() throws IOException {
    
        GetRequest request = new GetRequest();
        request.index("people").id("1001");
    
        GetResponse response = esClient.get(request, RequestOptions.DEFAULT);
    
        System.out.println(response);
        System.out.println(response.getSource());
    }
    复制代码
  • 删除文档

    @Test
    public void doc_delete() throws IOException {
        DeleteRequest request = new DeleteRequest();
        request.index("people").id("1001");
    
        DeleteResponse response = esClient.delete(request, RequestOptions.DEFAULT);
        System.out.println(response);
    }
    复制代码
文档批量操作

一般操作ES的数据都是批量保存或者批量删除,如果通过一条一条的操作,那么效率非常的低,可以通过批量操作API提高效率

  • 批量保存

    @Test
    public void doc_insert_batch() throws IOException {
        BulkRequest request = new BulkRequest();
        request.add(new IndexRequest().index("people").id("1001").source(XContentType.JSON, "name", "张三", "sex", "男", "age", 10));
        request.add(new IndexRequest().index("people").id("1002").source(XContentType.JSON, "name", "李四", "sex", "男", "age", 11));
        request.add(new IndexRequest().index("people").id("1003").source(XContentType.JSON, "name", "王五", "sex", "男", "age", 12));
        request.add(new IndexRequest().index("people").id("1004").source(XContentType.JSON, "name", "王五1", "sex", "男", "age", 8));
        request.add(new IndexRequest().index("people").id("1005").source(XContentType.JSON, "name", "王五2", "sex", "男", "age", 9));
        request.add(new IndexRequest().index("people").id("1006").source(XContentType.JSON, "name", "王五33", "sex", "男", "age", 7));
    
        BulkResponse response = esClient.bulk(request, RequestOptions.DEFAULT);
    
        System.out.println(response.getTook());
        System.out.println(Arrays.toString(response.getItems()));
    }
    复制代码
  • 批量删除

    @Test
    public void doc_delete_batch() throws IOException {
        BulkRequest request = new BulkRequest();
        request.add(new DeleteRequest().index("people").id("1001"));
        request.add(new DeleteRequest().index("people").id("1002"));
        request.add(new DeleteRequest().index("people").id("1003"));
    
        BulkResponse response = esClient.bulk(request, RequestOptions.DEFAULT);
    
        System.out.println(response.getTook());
        System.out.println(response);
    }
    复制代码

文档高级查询

高级查询、分组查询、分页、排序、聚合操作等,作为ES常用的查询操作,ES的Java客户端也提供了好用的API进行操作

  • 查询指定索引的所有数据

    @Test
    public void match_all() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.query(QueryBuilders.matchAllQuery());
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • term查询

    @Test
    public void query_term() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.query(QueryBuilders.termQuery("age", 10));
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • 分页查询

    @Test
    public void query_page() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.query(QueryBuilders.matchAllQuery());
    
        // from指定的是页数开始的偏移量, (当前页数 - 1)* size
        builder.from(0);
        builder.size(3);
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • 排序查询

    @Test
    public void query_sort() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.query(QueryBuilders.matchAllQuery());
    
        builder.sort("age", SortOrder.DESC);
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • 查询并过滤字段

    @Test
    public void query_filter() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.query(QueryBuilders.matchAllQuery());
    
        String[] excludes = {};
        String[] includes = {"name"};
        // 过滤字段,指定只包含某些字段,或者需要排除某些字段
        builder.fetchSource(includes, excludes);
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • bool条件查询,多条件Must

    @Test
    public void query_bool_must() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
    
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
    
        // 多条件查询,must -> 一定需要匹配到
        boolQueryBuilder.must(QueryBuilders.matchQuery("age", 10));
        boolQueryBuilder.must(QueryBuilders.matchQuery("sex", "女"));
    
    
        builder.query(boolQueryBuilder);
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • bool条件查询,多条件should

    @Test
    public void query_bool_should() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
    
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
    
        // 多条件查询,should -> 如果当前这条数据满足两个should条件中的任意一个,则表示满足条件
        boolQueryBuilder.should(QueryBuilders.matchQuery("age", 10));
        boolQueryBuilder.should(QueryBuilders.matchQuery("sex", "女"));
    
        builder.query(boolQueryBuilder);
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • 范围查询

    @Test
    public void query_range() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
    
        // 根据某个字段构建范围查询
        RangeQueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery("age");
    
        // 指定范围查询的条件数据
        rangeQueryBuilder.gte(9);
        rangeQueryBuilder.lte(12);
    
        builder.query(rangeQueryBuilder);
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • 模糊查询

    @Test
    public void query_fuzzy() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
    
        // 模糊查询,指定字段名称进行模糊查询,后面的指定模糊匹配的字符个数
        builder.query(QueryBuilders.fuzzyQuery("name", "王五").fuzziness(Fuzziness.ONE));
    
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
    
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
            //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
    }
    复制代码
  • 高亮查询

    @Test
    public void query_highlight() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
        TermsQueryBuilder termsQueryBuilder = QueryBuilders.termsQuery("sex", "女");
    
        // 设置查询方式
        builder.query(termsQueryBuilder);
    
        // 构建高亮字段
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.preTags("<font color='red'>"); // 设置标签前缀
        highlightBuilder.postTags("</font>"); // 设置标签后缀
        highlightBuilder.field("sex"); // 设置高亮字段
    
        // 设置高亮查询
        builder.highlighter(highlightBuilder);
    
        // 设置请求体
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
        System.out.println(response);
        SearchHits hits = response.getHits();
        System.out.println("took::"+response.getTook());
        System.out.println("time_out::"+response.isTimedOut());
        System.out.println("total::"+hits.getTotalHits());
        System.out.println("max_score::"+hits.getMaxScore());
        System.out.println("hits::::>>");
        for (SearchHit hit : hits) {
            String sourceAsString = hit.getSourceAsString();
            System.out.println(sourceAsString);
            //打印高亮结果
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            System.out.println(highlightFields);
        }
    }
    复制代码
  • 聚合查询—最大值

    @Test
    public void query_aggs_max() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
    
        // 聚合查询,获取最大的age字段的数
        builder.aggregation(AggregationBuilders.max("maxAge").field("age"));
    
        // 设置请求体
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
        System.out.println(response);
    }
    复制代码
  • 聚合查询—分组查询

    @Test
    public void query_aggs_group() throws IOException {
        SearchRequest request = new SearchRequest();
        request.indices("people");
    
        SearchSourceBuilder builder = new SearchSourceBuilder();
    
        // 聚合查询,获取最大的age字段的数
        builder.aggregation(AggregationBuilders.terms("age_groupby").field("age"));
    
        // 设置请求体
        request.source(builder);
    
        SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
        System.out.printl	n(response);
    }
    复制代码

文档的高级查询,JavaAPI的操作方式和语法基本和Http操作的一致,只不过将对应的Http方式替换为了API,可以更好的在程序中进行ES操作,下一篇一起看看如何在SpringBoot和ElasticSearch进行集成吧,更加方便的操作ES与索引数据

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