Elasticsearch入门学习（四）：使用javaAPI学习ES

摘要：一依赖刚开始少这个包创建索引失败官方文档并没有给这个提示二开始之前的准备官方文档连接操作所用到的实体类三关于索引的操作官方文档新增索引索引名称分片副本内容查询指定索引索引名称删除索引四关于文档的操作官方文档创建文档索引名称前

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        org.elasticsearch
        elasticsearch
        7.1.0
    
    
        org.elasticsearch.client
        elasticsearch-rest-high-level-client
        7.1.0
    

官方文档

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    /**
     * 连接ES
     * @return
     */
    public RestHighLevelClient start() {
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.100.151", 9201, "http"),
                        new HttpHost("192.168.100.151", 9202, "http"),
                        new HttpHost("192.168.100.151", 9203, "http")));
        return restHighLevelClient;
    }
 /**
 * 操作所用到的实体类
 */
@Data
class Article{
private long id;
private String title;
    public Article(long id, String title) {
        this.id = id;
        this.title = title;
    }
}

官方文档

新增索引

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  public void createIndex(RestHighLevelClient client) {
        //索引名称
        CreateIndexRequest request = new CreateIndexRequest("hello");
        //分片副本
        request.settings(Settings.builder().put("index.number_of_shards", 5)
                .put("index.number_of_replicas", 1));
        //内容
        Map  id = new HashMap <>();
        id.put("type","text");
        id.put("store",true);
        Map  title = new HashMap <>();
        title.put("type","text");
        title.put("store",true);
        title.put("index",true);
        title.put("analyzer", "standard");
        Map  properties = new HashMap <>();
        properties.put("id",id);
        properties.put("title",title);
        Map  mapping = new HashMap <>();
        mapping.put("properties",properties);
        request.mapping(mapping);
        try {
            CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
            System.out.println(response.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

查询指定索引

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public void getIndex(RestHighLevelClient client) throws IOException {
    //索引名称
    GetIndexRequest request = new GetIndexRequest("hello");
    try {
        boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);
        System.out.println(exists);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

删除索引

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public void delIndex(RestHighLevelClient client){
    DeleteIndexRequest request = new DeleteIndexRequest("hello");
    try {
        AcknowledgedResponse delete = client.indices().delete(request, RequestOptions.DEFAULT);
        System.out.println(delete.toString());
    } catch (IOException e) {
        e.printStackTrace();
    }
}

官方文档

创建文档

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    public void createDocument(RestHighLevelClient client){
        //索引名称
        IndexRequest indexRequest = new IndexRequest("hello");
        ObjectMapper mapper = new ObjectMapper();
        Article article = new Article(3L, "web前端");
        byte[] json = new byte[0];
        try {
            json = mapper.writeValueAsBytes(article);
            //可以设置文章ID
            indexRequest.id("5");
            indexRequest.source(json, XContentType.JSON);
            IndexResponse index = client.index(indexRequest, RequestOptions.DEFAULT);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

根据文档ID查询文档

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public void getDocument(RestHighLevelClient client){
    GetRequest getRequest = new GetRequest("hello", "1");
    GetResponse documentFields = null;
    try {
        documentFields = client.get(getRequest, RequestOptions.DEFAULT);
        System.out.println(documentFields.toString());
    } catch (IOException e) {
        e.printStackTrace();
    }
}

更新文档

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    public void updateDocument(RestHighLevelClient client){
        UpdateRequest  updateRequest = new UpdateRequest("hello", "1");
        Article article = new Article(2L, "java入门到放弃");
        ObjectMapper mapper = new ObjectMapper();
        byte[] json = new byte[0];
        try {
            json = mapper.writeValueAsBytes(article);
            IndexRequest indexRequest = new IndexRequest("hello");
            indexRequest.source(json, XContentType.JSON);
            updateRequest.doc(indexRequest);
            UpdateResponse updateResponse = client.update(
                    updateRequest, RequestOptions.DEFAULT);
            System.out.println(updateResponse);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

删除文档

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    public void delDocument(RestHighLevelClient client){
        DeleteRequest request = new DeleteRequest("hello", "1");
        try {
            DeleteResponse deleteResponse = client.delete(
                    request, RequestOptions.DEFAULT);
            System.out.println(deleteResponse);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

查询文档

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    public void searchDocument(RestHighLevelClient client){
        SearchRequest searchRequest = new SearchRequest();
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.matchAllQuery());
        searchRequest.source(searchSourceBuilder);
        SearchResponse searchResponse = null;
        try {
            searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
            System.out.println(searchResponse.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }