ElasticSearch入门(实战)

环境准备：VMware docker  

 创建一个linux虚拟机，使用docker pull elasticsearch 

部署单体服务： 

docker pull elasticsearch:6.8.13
#elasticsearch十分占用内存，用这种方式启动会导致Linux卡机
docker run -d --name elasticsearch -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" elasticsearch:6.8.13
#所以需要限制内存(-e ES_JAVA_OPTS='-Xms64m -Xmx512m')
docker run -d --name elasticsearch -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" -e ES_JAVA_OPTS='-Xms64m -Xmx512m' elasticsearch:6.8.13
可采用其他文章的创建ealsticsearch

测试是否创建成功： 浏览器访问部署机ip地址:9300 跳转 

tagline" : "You Know, for Search"显示成功

PostMan客户端工具

索引操作：

        创建索引：PUT  http://127.0.0.1:9200/shopping 具有幂等性，二次请求会产生错误

                          不允许用Post，不具有幂等性 

        查询&删除  GET    http://127.0.0.1:9200/shopping

                            DELETE    http://127.0.0.1:9200/shopping

文档操作：

        添加文档: POST    http://127.0.0.1:9200/shopping/_doc/1001  在请求体输入JSON格式的数据（必须传递数据不然会报错 request body is required）

        elasticsearch7以后 _type默认是_doc,/_doc后面没有自己添加的id会自动添加id，Post是全量修改

       查询文档 GET    http://127.0.0.1:9200/shopping/_doc/1001

                                   http://127.0.0.1:9200/_search  

        条件查询   GET  http://127.0.0.1:9200/shopping/_serach?q=数据:值 

                        or 请求体上查询

        分页查询  

                在请求体上加上 form 和 size 给相应的值 还有sort排序 _source 哪个字段

        多条件查询： 

       修改文档  POST OR PUT  全量修改 直接覆盖     http://127.0.0.1:9200/shopping/_doc/1001    Body内容修改

                       局部修改：    POST     http://127.0.0.1:9200/shopping/_update/1001 {"doc":{}}

JavaAPI 操作 ES

   环境准备 引入Maven依赖 版本7以前type需要自己制定，7以后默认为_doc

<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>6.5.4</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-client</artifactId>
    <version>6.5.4</version>
</dependency>
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>6.5.4</version>
</dependency>
创建ES 客户端 
        client = RestHighLevelClient client = new RestHighLevelClient(
        RestClient.builder(
                HttpHost.create("http://localhost:9200")
        )
);

索引操作：   

    创建索引： client.indices()
                        .create(new CreateIndexRequest().index("shopping"),RequestOptions.DEFAULT);

    查询or删除索引：
           查询：client.indices()
                .get(new GetIndexRequest().indices("shopping"),RequestOptions.DEFAULT);

           删除：client.indices()
        .delete(new DeleteIndexRequest().indices("shopping"),RequestOptions.DEFAULT); 

文档操作： 

     不需要写mapping映射属性 

       添加文档： 

        ObjectMapper objectMapper = new ObjectMapper();
        client.index(newIndexRequest("shopping").id("1002").type("_doc").source(objectMapper.writeValueAsString(//java对象),XContentType.JSON),RequestOptions.DEFAULT);      

        局部修改文档：

        UpdateRequest request = new UpdateRequest(); request.index("shopping"); request.id("2001"); request.doc(XContentType.JSON,objectMapper.writeValueAsString(//java对象) client.update(new UpdateRequest(),RequestOptions.DEFAULT);

        查询or删除文档：

        查询：

        GetRequest request = new GetRequest();
        request.index("shopping");
        request.id("2001");
        client.get(request,RequestOptions.DEFAULT);

        删除：

        DeleteRequest request = new DeleteRequest();
        request.index("shopping");
        request.id("2001");
        client.delete(request,RequestOptions.DEFAULT);

        批量删除 or 增加： 

        BulkRequest request = new BulkRequest();
        bulk.add();//有增加、删除的request
        client.bulk(request,RequestOptions.DEFAULT);

  查询：

        全量查询:               

SearchRequest request = new SearchRequest();
request.indices("shopping");
request.source(new SearchSourceBuilder().query(QueryBuilders.matchAllQuery()));
client.search(request,RequestOptions.DEFAULT);

  条件查询：          

SearchRequest request = new SearchRequest();
request.indices("shopping");
request.source(new SearchSourceBuilder().query(QueryBuilders.termQuery("age",12)));
client.search(request,RequestOptions.DEFAULT);

        分页查询：        

SearchRequest request = new SearchRequest();
request.indices("shopping");
SearchSourceBuilder query = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());
query.from();
query.sort();
query.size();
request.source(query);
client.search(request,RequestOptions.DEFAULT);

        字段查询：        

SearchRequest request = new SearchRequest();
request.indices("shopping");
SearchSourceBuilder query = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());
String[] excludes = {};
String[] includes = {};
query.fetchSource(includes,excludes);
request.source(query);
client.search(request,RequestOptions.DEFAULT);

        组合查询：

SearchRequest request = new SearchRequest();
request.indices("shopping");
SearchSourceBuilder builder = new SearchSourceBuilder();
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
boolQueryBuilder.must();
boolQueryBuilder.should();
boolQueryBuilder.mustNot();
builder.query(boolQueryBuilder);
request.source(builder);
client.search(request,RequestOptions.DEFAULT);

        范围查询： 

SearchRequest request = new SearchRequest();
request.indices("shopping");
SearchSourceBuilder builder = new SearchSourceBuilder();
RangeQueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery("age");
rangeQueryBuilder.gte(30);
rangeQueryBuilder.lte(40);
builder.query(rangeQueryBuilder;
request.source(builder);
client.search(request,RequestOptions.DEFAULT);

       模糊查询：        

SearchRequest request = new SearchRequest();
request.indices("shopping");
SearchSourceBuilder builder = new SearchSourceBuilder() ;
FuzzyQueryBuilder fuzzyQueryBuilder = QueryBuilders.fuzzyQuery("name","wangwu").fuzziness(Fuzziness.ONE);
builder.query(fuzzyQueryBuilder;
request.source(builder);
client.search(request,RequestOptions.DEFAULT);