Elasticsearch学习3《Java操作elasticsearch》

分手后的思念是犯贱 2022-12-23 03:28 29阅读 0赞

### 目录 ###

*  一、JAVA连接ES
 *   *  1、添加依赖
     *  2、在utils目录下创建EsClient 类
     *  3、在test类中测试
 *  二、索引
 *   *  1、创建索引
     *  2、效果
     *  3、删除索引
 *  三、文档操作
 *   *  1、添加文档
     *  2、修改文档
     *  3、删除文档
     *  4、批量操作 新增
     *  5、批量 删除
     *  6、批量导入数据库数据到ES
 *  四、封装查询
 *   *  1、准备EsClient类连接ES
     *  2、新建EsKeyWordService类
     *  3、新建EsKeyWordServiceImpl类
     *  4、新建EsKeywordController类
     *  5、测试

# 一、JAVA连接ES #

## 1、添加依赖 ##

<dependency>
                <groupId>org.elasticsearch</groupId>
                <artifactId>elasticsearch</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>
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
            </dependency>
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
                
                <scope>provided</scope>
            </dependency>

## 2、在utils目录下创建EsClient 类 ##

创建EsClient 连接

> 注意：需要先打开elasticsearch，然后配置下面的host连接

public class EsClient { 
    
        public static RestHighLevelClient getClient(){ 
            // 创建 HttpHost
            HttpHost httpHost = new HttpHost("127.0.0.1",9200);
    
            // 创建 RestClientBuilder
            RestClientBuilder builder = RestClient.builder(httpHost);
    
            // 创建 RestHighLevelClient
            RestHighLevelClient client = new RestHighLevelClient(builder);
    
            return client;
        }
    }

## 3、在test类中测试 ##

@Test
        public void testConnect() { 
            try { 
                RestHighLevelClient client = ESClient.getClient();
                System.out.println("ok!");
            } catch (Exception e) { 
                System.out.println(e);
            }
        }

连接成功：

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ1MjM0NTEw_size_16_color_FFFFFF_t_70_pic_center]

# 二、索引 #

## 1、创建索引 ##

RestHighLevelClient client =  EsClient.getClient();
        String index = "person";
        String type="man";
    
        @Test
        public void createIndx() throws Exception{ 
            // 1.准备关于索引的setting
            Settings.Builder settings = Settings.builder()
                    .put("number_of_shards", 2)     //指定索引的分片数
                    .put("number_of_replicas", 1);  //指定索引的备份数
    
            // 2.准备关于索引的mapping
            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 封装到到一个Request对象中
            CreateIndexRequest request = new CreateIndexRequest(index)
                    .settings(settings)
                    .mapping(type,mappings);
    
            // 4.使用client 去连接ES
            CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
    
            System.out.println("response:"+response.toString());
        }

## 2、效果 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ1MjM0NTEw_size_16_color_FFFFFF_t_70_pic_center 1]

## 3、删除索引 ##

//删除索引
       	RestHighLevelClient client =  EsClient.getClient();
        String index = "person";
        String type="man";
        
        @Test
        public void deleteIndex() throws Exception{ 
            //1.准备request对象
            GetIndexRequest request=new GetIndexRequest();
            request.indices(index);
            //2.通过Cilent操作
            RestHighLevelClient client = EsClient.getClient();
            boolean exists= client.indices().exists(request,RequestOptions.DEFAULT);
            //3.输出
            if (exists){ 
                // 1.获取request
                DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest(index);
                // 2.使用client 操作request 删除索引
                AcknowledgedResponse delete = client.indices().delete(deleteIndexRequest, RequestOptions.DEFAULT);
                // 3.输出结果
                System.out.println(delete.isAcknowledged());
            }else { 
                System.out.println("没有该索引");
            }
            
        }

# 三、文档操作 #

## 1、添加文档 ##

首先导入jackson依赖

<dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
            </dependency>

创建实体类

@Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class KeyText { 
    
        @JsonIgnore
        private Integer id;
        private String kwname;
        private String text;
    }

测试：

ObjectMapper mapper = new ObjectMapper();
        RestHighLevelClient client =  EsClient.getClient();
        String index = "keytext";
        String type="ktext";
    
    	//添加文档
        @Test
        public void createDocTest() throws IOException { 
    
            // 1.准备一个json数据
            KeyText keyText = new KeyText(1,"ws","ws内容");
            String json = mapper.writeValueAsString(keyText);
    
            // 2.创建一个request对象(手动指定的方式创建)
            IndexRequest request = new IndexRequest(index,type,keyText.getId().toString());
            request.source(json, XContentType.JSON);
    
            // 3.使用client 操作request对象生成doc
            IndexResponse response = client.index(request, RequestOptions.DEFAULT);
    
            // 4.输出返回结果
            System.out.println(response.getResult().toString());
    
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ1MjM0NTEw_size_16_color_FFFFFF_t_70_pic_center 2]

## 2、修改文档 ##

ObjectMapper mapper = new ObjectMapper();
        RestHighLevelClient client =  EsClient.getClient();
        String index = "keytext";
        String type="ktext";
        
        //修改文档
        @Test
        public void updateDocTest() throws Exception{ 
            // 1.创建要更新的Map
            Map<String,Object>  doc = new HashMap<>();
            doc.put("kwname","ps");
    
            // 2.创建request, 将doc 封装进去
            UpdateRequest request = new UpdateRequest(index,type,"1");
            request.doc(doc);
    
            // 3. client 去操作 request
            UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
            // 4.输出 更新结果
            System.out.println(response.getResult());
        }

## 3、删除文档 ##

ObjectMapper mapper = new ObjectMapper();
        RestHighLevelClient client =  EsClient.getClient();
        String index = "keytext";
        String type="ktext";
    
        @Test
        public void deleteDocTest() throws  Exception{ 
            // 1.封装删除对象
            DeleteRequest request = new DeleteRequest(index,type,"1");
    
            // 2 client 操作 request对象
            DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
            // 3.输出结果
            System.out.println(response.getResult().toString());
        }

## 4、批量操作 新增 ##

ObjectMapper mapper = new ObjectMapper();
        RestHighLevelClient client =  EsClient.getClient();
        String index = "keytext";
        String type="ktext";
        
        @Test
        public void bulkCreateDoc() throws  Exception{ 
            // 1.准备多个json 对象
            KeyText keyText1 = new KeyText(1,"ws","ws内容");
            KeyText keyText2 = new KeyText(2,"ps","ps内容");
            KeyText keyText3 = new KeyText(3,"ea","ea内容");
    
            String json1  = mapper.writeValueAsString(keyText1);
            String json2  = mapper.writeValueAsString(keyText2);
            String json3  = mapper.writeValueAsString(keyText3);
    
            // 2.创建request
            BulkRequest bulkRequest = new BulkRequest();
            bulkRequest.add(new IndexRequest(index,type,keyText1.getId().toString()).source(json1,XContentType.JSON))
                    .add(new IndexRequest(index,type,keyText2.getId().toString()).source(json2,XContentType.JSON))
                    .add(new IndexRequest(index,type,keyText3.getId().toString()).source(json3,XContentType.JSON));
    
            // 3.client 执行
            BulkResponse responses = client.bulk(bulkRequest, RequestOptions.DEFAULT);
    
            // 4.输出结果
            System.out.println(responses.getItems().toString());
        }

## 5、批量 删除 ##

ObjectMapper mapper = new ObjectMapper();
        RestHighLevelClient client =  EsClient.getClient();
        String index = "keytext";
        String type="ktext";
        
        @Test
    	public void bulkDelete() throws Exception{ 
    	    // 1.创建Request 对象
    	    BulkRequest bulkRequest = new BulkRequest();
    	    bulkRequest.add(new DeleteRequest(index,type,"1"));
    	    bulkRequest.add(new DeleteRequest(index,type,"2"));
    	    bulkRequest.add(new DeleteRequest(index,type,"3"));
    	    // 2.执行
    	    BulkResponse re = client.bulk(bulkRequest, RequestOptions.DEFAULT);
    	    // 3.输出结果
    	    System.out.println(re.toString());
    	
    	}

## 6、批量导入数据库数据到ES ##

/** * 添加文章 * @throws IOException */
    
        @Autowired
        KeyWordService keyWordService;
        
        ObjectMapper mapper = new ObjectMapper();
        RestHighLevelClient client =  EsClient.getClient(); 
        String index = "keywordlist";
        String type="tweet";
        
        @Test
        public void addDOC2() throws IOException{ 
            // 1.准备一个json数据
            List<KeyWord> keyWordList = keyWordService.findAll();
            for (int i = 0; i < keyWordList.size(); i++) { 
                String json = mapper.writeValueAsString(keyWordList.get(i));
                // 2.创建一个request对象(手动指定的方式创建)
                IndexRequest request = new IndexRequest(index,type,keyWordList.get(i).getKwid());
                request.source(json, XContentType.JSON);
    
                // 3.使用client 操作request对象生成doc
                IndexResponse response = client.index(request, RequestOptions.DEFAULT);
                // 4.输出返回结果
                System.out.println(response.getResult().toString());
            }
        }

# 四、封装查询 #

## 1、准备EsClient类连接ES ##

public class EsClient { 
    
        public static RestHighLevelClient getClient(){ 
            // 创建 HttpHost
            HttpHost httpHost = new HttpHost("47.115.5.93",9200);
    
            // 创建 RestClientBuilder
            RestClientBuilder builder = RestClient.builder(httpHost);
    
            // 创建 RestHighLevelClient
            RestHighLevelClient client = new RestHighLevelClient(builder);
    
            return client;
        }
    }

## 2、新建EsKeyWordService类 ##

import java.util.ArrayList;
    import java.util.Map;
    
    public interface EsKeyWordService { 
        ArrayList<Map<String,Object>> findByEsKeyword(String eskeyword);
    }

## 3、新建EsKeyWordServiceImpl类 ##

@Service
    public class EsKeyWordServiceImpl implements EsKeyWordService { 
    
        RestHighLevelClient restHighLevelClient =  EsClient.getClient();  // 连接ES
        String index = "keywordlist";   // 索引
        String type="tweet";           // 类型
    
    
        /** * 根据关键词查询 * @param eskeyword * @return */
        @SneakyThrows
        @Override
        public ArrayList<Map<String,Object>> findByEsKeyword(String eskeyword) { 
            //1.创建request对象
            SearchRequest searchRequest=new SearchRequest(index);
            searchRequest.types(type);
            //2.指定查询条件
            SearchSourceBuilder builder=new SearchSourceBuilder();
            
             //这里使用 kwname.keyword 可解决中文查询为空的问题
            builder.query(QueryBuilders.termQuery("kwname.keyword",eskeyword));
            //builder.query(QueryBuilders.matchPhraseQuery("kwname",eskeyword));
            
            searchRequest.source(builder);
            //执行查询
            SearchResponse rsp = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
            //存放数据
            ArrayList<Map<String,Object>> keyWordList = new ArrayList<>();
            for (SearchHit hit:rsp.getHits().getHits()) { 
                keyWordList.add(hit.getSourceAsMap());
            }
            //返回数据
            return keyWordList;
        }
    }

## 4、新建EsKeywordController类 ##

@RestController
    public class EsKeywordController { 
    
        private ResultInfo info;
        @Autowired
        EsKeyWordService esKeyWordService;
    
        @ModelAttribute
        public void init() { 
            info = new ResultInfo();
        }
    
        /** * 根据关键词查询 * @param keyword * @return */
        @GetMapping("/es")
        public ResultInfo EsKeywordList(String keyword){ 
            ArrayList<Map<String,Object>> keyWordList = esKeyWordService.findByEsKeyword(keyword);
            if (keyWordList != null){ 
                info.setData(keyWordList);
            }else { 
                info.setMsg(Code.NODATA);
            }
            return info;
        }
    }

## 5、测试 ##

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