首页手记 ElasticSearch 遇见(2)

ElasticSearch 遇见(2)

标签：

Java

希望给同样遇见es的你带来帮助，也希望彼此有更多的讨论
版本选择6.4.3
1-Java 客户端的使用 (上)
  建立连接
  增删改数据
  测试

1-引入MAVEN依赖:

使用官方的Java High Level REST

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>6.4.3</version>
</dependency>

2-建立连接

我的项目依赖springboot,因此会先把客户端当成一个bean来使用。

    @Bean
    public RestHighLevelClient client(){
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.88.130", 9200, "http")));

        return client;
    }

3-增删改数据

先定义接口和实体类已经需要的常量信息

public interface SearchService {

    //索引操作
    void createOrUpdate(CometIndex cometIndex);

    void remove(Long cometId);

    //查询 接口
    List <CometIndexVO> query(RentSearch rentSearch);

    //自动补全接口
    List<String> suggest(String prefix);

}

@Getter
@Setter
public class CometIndex {
    private Long cometId;          //唯一标示

    private String title;                   //标题

    private String author;                  //原创者

    private String editor;        //责任编辑

    private String category;                //分类

    private String description;             //描述

    private String content;                 //内容

    private Date createTime;             //创建时间

    private List<CometSuggest> suggest;  //固定格式 ES

}

public class CometIndexKey {

    public static final String INDEX_NAME="comet";

    public static final String COMET_ID="cometId";          //唯一标示

    public static final String TITLE="title";                   //标题

    public static final String AUTHOR="author";                   //原创者

    public static final String EDITOR="editor";         //责任编辑

    public static final String CATEGORY="category";                 //分类

    public static final String DESCRIPTION="description";              //描述

    public static final String CONTENT="content";                  //内容

    public static final String CREATE_TIME="createTime";              //创建时间

}

@Getter
@Setter
public class CometSuggest {

    private String input;

    private int weight=10;//权重

}

实现增删改

    @Autowired
    private ObjectMapper objectMapper;

    @Autowired
    private RestHighLevelClient client;

    @Override
    public void createOrUpdate(CometIndex cometIndex) {

        //判断是否已经存在
        long id = cometIndex.getCometId();

        //构建查询
        SearchRequest searchRequest = new SearchRequest();
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.termQuery(CometIndexKey.COMET_ID, id));
        searchRequest.source(searchSourceBuilder);

        try {
            SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
            long totalHit = searchResponse.getHits().getTotalHits();
            log.info("create  index before totalHit:{}", totalHit);
            boolean success = false;
            if (totalHit == 0) {
                success = create(cometIndex);//新增数据
            } else if (totalHit == 1) {
                String esId = searchResponse.getHits().getAt(0).getId();//获取ID
                success = update(esId, cometIndex);//更新数据
            } else {//同一个数据存了多个
                success = deleteAndCreate(totalHit, cometIndex);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }

    }
	
	private boolean create(CometIndex cometIndex) {
        log.info("create");
        if (!updateSuggest(cometIndex)) {
            return false;
        }

        try {

            IndexRequest indexRequest = new IndexRequest(CometIndexKey.INDEX_NAME, CometIndexKey.INDEX_NAME)
                    .source(objectMapper.writeValueAsString(cometIndex), XContentType.JSON);

            IndexResponse response = client.index(indexRequest, RequestOptions.DEFAULT);

            if (response.getResult() == DocWriteResponse.Result.CREATED) {
                return true;
            } else {
                return false;
            }

        } catch (Exception e) {
            e.printStackTrace();
            log.info("Error Index with comet:{}", cometIndex.getCometId());
            return false;
        }

    }

    private boolean update(String esId, CometIndex cometIndex) {
        log.info("update");
        if (!updateSuggest(cometIndex)) {
            return false;
        }

        try {

            UpdateRequest updateRequest = new UpdateRequest(CometIndexKey.INDEX_NAME, CometIndexKey.INDEX_NAME, esId)
                    .doc(objectMapper.writeValueAsString(cometIndex), XContentType.JSON);

            UpdateResponse response = client.update(updateRequest, RequestOptions.DEFAULT);

            if (response.getResult() == DocWriteResponse.Result.UPDATED) {
                return true;
            } else {
                return false;
            }

        } catch (Exception e) {
            e.printStackTrace();
            log.info("Error update Index with comet:{}", cometIndex.getCometId());
            return false;
        }

    }

    private boolean deleteAndCreate(long totalHit, CometIndex cometIndex) {

        remove(cometIndex.getCometId());

        return create(cometIndex);
    }
	
	
	@Override
    public void remove(Long cometId) {

        RestClient restClient = client.getLowLevelClient();//获取 low api
        String endPoint = "/" + CometIndexKey.INDEX_NAME + "/" + CometIndexKey.INDEX_NAME + "/_delete_by_query";

        try {
            XContentBuilder builder = XContentFactory.jsonBuilder();

            builder.startObject()
                    .startObject("query")
                    .startObject("term")
                    .field(CometIndexKey.COMET_ID, cometId)
                    .endObject()
                    .endObject()
                    .endObject();

            IndexRequest indexRequest = new IndexRequest().source(builder);

            HttpEntity entity = new NStringEntity(indexRequest.source().utf8ToString(), ContentType.APPLICATION_JSON);

            Request request = new Request(
                    "POST",
                    endPoint);
            request.setEntity(entity);

            Response response = restClient.performRequest(request);

            log.info("response:{}", response.toString());

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

4-测试

 @Test
    public void createOrUpdate(){
        CometIndex cometIndex=new CometIndex();
        cometIndex.setCometId(4l);
        cometIndex.setAuthor("大王叫我来巡山");
        cometIndex.setCategory("question");
        cometIndex.setContent("hey es ,我是来自西游记的大魔王,来巡山了。");
        cometIndex.setDescription("nothing");
        cometIndex.setEditor("cctv");
        cometIndex.setTitle("西游记故事新编");
        cometIndex.setCreateTime(new Date());
        searchService.createOrUpdate(cometIndex);
    }
可以修改测试数据进行继续测试。
完整代码后续会提供github地址