ElasticSearch入门之Java API操作es, Java API完成对es的增删改查以及高亮分页, Java API批量插入文档到es集群 16

深碍√TFBOYSˉ_ 2021-10-14 04:38 290阅读 0赞

# 1. 先导入pom依赖 #

<dependencies>
            <dependency>
                <groupId>org.elasticsearch.client</groupId>
                <artifactId>transport</artifactId>
                <version>6.0.0</version>
            </dependency>
            
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-core</artifactId>
                <version>2.9.1</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
            </dependency>
        </dependencies>

# 2. 创建索引 prepareIndex #

## 2.1 创建Client ##

private TransportClient client; 
    @Before
        public void initClient() throws UnknownHostException { 
            client = new PreBuiltTransportClient(Settings.builder().put("cluster.name", "myes").build())
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("node01"), 9300))
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("node02"), 9300))
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("node03"), 9300));
        }

## 2.2 打印并关闭Clinet ##

private IndexResponse indexResponse;
        @After
        public void printResultAndCloseClient() { 
            System.out.println("index:" + indexResponse.getIndex());
            System.out.println("type:" + indexResponse.getType());
            System.out.println("id:" + indexResponse.getId());
            System.out.println("version:" + indexResponse.getVersion());
            System.out.println("status:" + indexResponse.getResult());
            client.close();
        }
    ```
    ## 2.3 自己拼装json插入文档到es集群
    ```java
     @Test
        public void index1() throws Exception { 
            String json = "{" +
                    "\"user\":\"kimchy\"," +
                    "\"postDate\":\"2013-01-30\"," +
                    "\"message\":\"travelying out Elasticsearch\"" +
                    "}";
            indexResponse = client.prepareIndex("news", "article", "1")
                    .setSource(json, XContentType.JSON)
                    .get();
        }

## 2.4 使用map插入文档到es集群 ##

@Test
        public void index2() throws Exception { 
            HashMap<String, String> jsonMap = new HashMap<String, String>();
            jsonMap.put("name", "zhangsan");
            jsonMap.put("sex", "1");
            jsonMap.put("age", "18");
            jsonMap.put("address", "bj");
    
            indexResponse = client.prepareIndex("news", "article", "2")
                    .setSource(jsonMap)
                    .get();
        }

## 2.5 XcontentBuilder转化成json数据插入文档到es集群 ##

@Test
        public void index3() throws IOException { 
            indexResponse = client.prepareIndex("news", "article", "3")
                    .setSource(new XContentFactory().jsonBuilder()
                            .startObject()
                            .field("name", "lisi")
                            .field("age", "18")
                            .field("sex", "0")
                            .field("address", "bj")
                            .endObject())
                    .get();
    
        }

## 2.6 批量插入文档 ##

/** * 批量插入文档，可以提高创建索引的速度，主要减少网络请求。 * 如果正常情况，创建一个文档就会发送一次网络请求，其实就是发起一次http请求。 * bulkIndex就可以将多个文档合并在一起之后，发送一次请求。 * @throws IOException */
    @Test
        public void index4() throws IOException { 
            BulkRequestBuilder bulk = client.prepareBulk();
            bulk.add(client.prepareIndex("news", "article", "4")
                    .setSource(new XContentFactory().jsonBuilder()
                            .startObject()
                            .field("name", "wangwu")
                            .field("age", "18")
                            .field("sex", "0")
                            .field("address", "bj")
                            .endObject()));
            bulk.add(client.prepareIndex("news", "article", "5")
                    .setSource(new XContentFactory().jsonBuilder()
                            .startObject()
                            .field("name", "zhaoliu")
                            .field("age", "18")
                            .field("sex", "0")
                            .field("address", "bj")
                            .endObject()));
            BulkResponse bulkResponse = bulk.get();
            System.out.println(bulkResponse);
        }

## 2.7 导入Gson依赖插入文档 ##

<dependency>
                <groupId>com.google.code.gson</groupId>
                <artifactId>gson</artifactId>
                <version>2.8.2</version>
            </dependency>

@Test
        public  void  index5(){ 
            Gson gson = new Gson();
            User user = new User("6", "itcast", "18", "1");
            String json = gson.toJson(user);
            System.out.println(json);
           indexResponse =  client.prepareIndex("news","article",user.getId())
                    .setSource(json,XContentType.JSON)
                    .get();
    
        }

# 3. 查询索引 #

# 3.1 使用prepareGet查询数据 #

@Test
        public void query1(){ 
            GetResponse response = client.prepareGet().setIndex("news").setType("article").setId("1").get();
            String index= response.getIndex();
            String type= response.getType();
            String id= response.getId();
            System.out.println(response.getSourceAsString());
            System.out.println(index);
            System.out.println(type);
            System.out.println(id);
    
            client.close();
        }

## 3.2 使用prepareMultiGet减少网络请求查询数据 ##

@Test
        public void query2(){ 
            MultiGetResponse responses = client.prepareMultiGet().add("news", "article", "1")
                    .add("news", "article", "2")
                    .add("news", "article", "3")
                    .add("news", "article", "4")
                    .get();
            ArrayList<User> users = new ArrayList<User>();
            for (MultiGetItemResponse response : responses) { 
                String json = response.getResponse().getSourceAsString();
                Gson gson = new Gson();
                User user = gson.fromJson(json, User.class);
                users.add(user);
            }
            System.out.println(users);
        }

## 3.3 使用search查询数据并分页 ##

### 3.3.1 分页前的配置文件 ###

由于分页前需要排序，所以需要配置id字段的fielddata属性等于true。

DELETE blog2
    PUT /blog2/?pretty
    PUT blog2/_mapping/article
    { 
      "properties": { 
        "id": {  
          "type":     "text",
          "fielddata": true
        },
        "title": {  
          "type":     "text"
        },
        "content": {  
          "type":     "text"
        }
      }
    }

### 3.3.2 分页的java代码 ###

@Test
        public void query3(){ 
            SearchResponse response = client.prepareSearch("blog2").setTypes("article")
                    //所用的查询方式都可以直接new出来，
                    .setQuery(new MatchAllQueryBuilder())
                    //fieldData=true
                    .addSort("id", SortOrder.DESC)
                    //浅分页
                    .setFrom(5).setSize(5)
                    .get();
            SearchHits hits = response.getHits();
            for (SearchHit hit : hits) { 
                System.out.println(hit.getSourceAsString());
    // //docid没有值，旧版本有值
    // int docId = hit.docId();
    // System.out.println(docId);
            }
        }

### 3.3.3 分页的数据准备 ###

@Test
        public void initPageData() throws UnknownHostException { 
            // 创建Client连接对象
            Settings settings = Settings.builder().put("cluster.name", "myes").build();
            TransportClient client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("node01"), 9300));
    
            for (int i = 1; i <= 100; i++) { 
                // 描述json 数据
                Article article = new Article();
                article.setId(i+"");
                article.setTitle(i + "搜索工作其实很快乐");
                article.setContent(i
                        + "我们希望我们的搜索解决方案要快，我们希望有一个零配置和一个完全免费的搜索模式，我们希望能够简单地使用JSON通过HTTP的索引数据，我们希望我们的搜索服务器始终可用，我们希望能够一台开始并扩展到数百，我们要实时搜索，我们要简单的多租户，我们希望建立一个云的解决方案。Elasticsearch旨在解决所有这些问题和更多的问题。");
    
                Gson gson = new Gson();
                String json = gson.toJson(article);
    
                // 建立文档
                client.prepareIndex("blog22222", "article", article.getId())
                        .setSource(json,XContentType.JSON)
                        .get();
            }
    
            //释放资源
            client.close();
        }

### 3.3.4 分页配置IK分词器 ###

PUT /blog22222?pretty
    { 
        "settings" : { 
            "analysis" : { 
                "analyzer" : { 
                    "ik" : { 
                        "tokenizer" : "ik_max_word"
                    }
                }
            }
        },
        "mappings" : { 
            "article" : { 
                "dynamic" : true,
                "properties" : { 
                    "id" : { 
                        "type" : "text",
                        "fielddata": true
                    },
                    "title" : { 
                        "type" : "text",
                        "analyzer" : "ik_max_word"
                    },
                    "content" : { 
                        "type" : "text",
                        "analyzer" : "ik_max_word"
                    }
                }
            }
        }
    }

# 4 删除索引 #

package cn.itcast.es.api;
    
    import org.elasticsearch.action.ActionListener;
    import org.elasticsearch.action.delete.DeleteResponse;
    import org.elasticsearch.client.transport.TransportClient;
    import org.elasticsearch.common.settings.Settings;
    import org.elasticsearch.common.transport.TransportAddress;
    import org.elasticsearch.index.query.QueryBuilders;
    import org.elasticsearch.index.reindex.BulkByScrollResponse;
    import org.elasticsearch.index.reindex.DeleteByQueryAction;
    import org.elasticsearch.rest.RestStatus;
    import org.elasticsearch.transport.client.PreBuiltTransportClient;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    
    import java.net.InetAddress;
    import java.net.UnknownHostException;
    
    public class DeleteIndex { 
        private TransportClient client;
        private DeleteResponse response;
    
        @Before
        public void init() throws UnknownHostException { 
            Settings settings = Settings.builder().put("cluster.name", "myes").build();
            client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("node01"), 9300));
        }
    
        @After
        public void close() throws UnknownHostException { 
            if(response!=null) { 
                String index = response.getIndex();
                String type = response.getType();
                String id = response.getId();
                long version = response.getVersion();
                System.out.println("index " + index + " type" + type + "" + id + "" + version + "" + version);
                RestStatus status = response.status();
                System.out.println("status:" + status.getStatus());
                client.close();
            }
        }
    
        /** * 根据文档进行删除 * @throws UnknownHostException */
        @Test
        public void delete1() throws UnknownHostException { 
            response = client.prepareDelete("twitter", "doc", "100").get();
        }
        @Test
        /** * 根据根据查询结果删除数据，并触发相关事件 */
        public void delete2() throws UnknownHostException { 
            DeleteByQueryAction.INSTANCE.newRequestBuilder(client)
                    .filter(QueryBuilders.matchQuery("gender", "male"))
                    .source("twitter")
                    .execute(new ActionListener<BulkByScrollResponse>() { 
                        public void onResponse(BulkByScrollResponse response) { 
                            long deleted = response.getDeleted();
                            System.out.println("---------------"+deleted);
                        }
                        public void onFailure(Exception e) { 
                            System.out.println("------------错误了");
                        }
                    });
        }
    }

# 5 查询结果高亮操作 #

## 5.1 什么是高亮显示 ##

在进行关键字搜索时，搜索出的内容中的关键字会显示不同的颜色，称之为高亮

*  百度搜索关键字"啊策策"  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY0MTkwOQ_size_16_color_FFFFFF_t_70]  
    插播个小广告,百度搜索**啊策策**可以搜到博主呦~
 *  京东商城搜索"笔记本"  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY0MTkwOQ_size_16_color_FFFFFF_t_70 1]

## 5.2 高亮显示的html分析 ##

通过开发者工具查看高亮数据的html代码实现：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY0MTkwOQ_size_16_color_FFFFFF_t_70 2]  
**ElasticSearch可以对查询出的内容中关键字部分进行标签和样式的设置，但是你需要告诉ElasticSearch使用什么标签对高亮关键字进行包裹**

## 5.3 高亮显示代码实现 ##

@Test
    //高亮查询
    public void test11() throws Exception{ 
        // 创建Client连接对象
        Settings settings = Settings.builder().put("cluster.name", "my-elasticsearch").build();
        TransportClient client = new PreBuiltTransportClient(settings)
            .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
    
        // 搜索数据
        SearchRequestBuilder searchRequestBuilder = client
            .prepareSearch("blog2").setTypes("article")
            .setQuery(QueryBuilders.termQuery("title", "搜索"));
    
        //设置高亮数据
        HighlightBuilder hiBuilder=new HighlightBuilder();
        hiBuilder.preTags("<font style='color:red'>");
        hiBuilder.postTags("</font>");
        hiBuilder.field("title");
        searchRequestBuilder.highlighter(hiBuilder);
    
        //获得查询结果数据
        SearchResponse searchResponse = searchRequestBuilder.get();
    
        //获取查询结果集
        SearchHits searchHits = searchResponse.getHits();
        System.out.println("共搜到:"+searchHits.getTotalHits()+"条结果!");
        //遍历结果
        for(SearchHit hit:searchHits){ 
            System.out.println("String方式打印文档搜索内容:");
            System.out.println(hit.getSourceAsString());
            System.out.println("Map方式打印高亮内容");
            System.out.println(hit.getHighlightFields());
    
            System.out.println("遍历高亮集合，打印高亮片段:");
            Text[] text = hit.getHighlightFields().get("title").getFragments();
            for (Text str : text) { 
                System.out.println(str);
            }
        }
    
        //释放资源
        client.close();
    }

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