springboot使用ElasticSearch

springboot使用ElasticSearch

使用ES官方自带的java客户端(Java High Level REST Client)进行操做，不使用spring data 封装好的模板。
由于没有人比ES官方更了解本身的产品

1. 导入依赖包

<!--Elastic Search 客户端  start-->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.6.2</version>
        </dependency>
        <!--若是elasticsearch-rest-high-level-client包中依赖的elasticsearch等版本不一致,须要手动引入相同版本-->
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.6.2</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-client</artifactId>
            <version>7.6.2</version>
        </dependency>
        <!--Elastic Search 客户端  end-->

2. 建立application.yml 配置文件

elasticsearch:
  hostList: localhost:9200 #多个节点用逗号隔开

3. 添加配置类

@Component
@PropertySource("classpath:application.yml")//配置文件地址，能够自定义
@ConfigurationProperties("elasticsearch")//属性前缀
public class ElasticSearchConfig {
    //    @Value("${elasticsearch.hostList}")
    private String hostList;//配置文件中的属性

    public String getHostList() {
        return hostList;
    }

    public void setHostList(String hostList) {
        this.hostList = hostList;
    }

    @Bean(value = "RestHighLevelClient", destroyMethod = "close")
    public RestHighLevelClient restHighLevelClient() {
        //经过逗号分割节点
        String[] split = hostList.split(",");
        HttpHost[] httpHosts = new HttpHost[split.length];
        for (int i = 0; i < split.length; i++) {
            //经过冒号分离出每个节点的ip,port
            String[] split1 = split[i].split(":");
            //这里http写固定了，只为测试使用，能够经过读取配置文件赋值的方式优化
            httpHosts[i] = new HttpHost(split1[0], Integer.parseInt(split1[1]), "http");
        }
        return new RestHighLevelClient(RestClient.builder(httpHosts));
    }
}

4. 在springboot test中测试CURD操做，具体查看 官方文档

@SpringBootTest
public class ElasticTest {

    @Autowired
    @Qualifier("RestHighLevelClient")
    private RestHighLevelClient client;
    /**
     * 添加数据
     * @throws IOException
     */
    @Test
    public void index() throws IOException {
        UserTest userTest = new UserTest();
        userTest.setName("董28");
        userTest.setSex("男");
        //因为客户端不支持自定义实体对象类做为添加数据的参数，因此提早先将对象转化为Map对象
        Map map = entityToMap(userTest);
        System.out.println(map);
        IndexRequest indexRequest = new IndexRequest("posts")
                .source(map);
        //异步
        client.indexAsync(indexRequest, RequestOptions.DEFAULT, new ActionListener<IndexResponse>() {

            @Override
            public void onResponse(IndexResponse indexResponse) {
                System.out.println(indexResponse);
                if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
                    //新建
                } else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
                    //修改
                }
                ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
                if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
                    //
                }
                if (shardInfo.getFailed() > 0) {
                    for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
                        String reason = failure.reason();
                    }
                }

            }

            @Override
            public void onFailure(Exception e) {
                System.out.println("exception...");
            }
        });
        //同步
        /*IndexRequest indexRequest = new IndexRequest("posts")
                .id("3").source(map);
        IndexResponse index = client.index(indexRequest, RequestOptions.DEFAULT);
        System.out.println(index);*/

    }

    /**
     * 经过索引index,id查询
     * 
     */
    @Test
    public void get() throws IOException {
        GetRequest getRequest = new GetRequest("posts", "1");
        /*FetchSourceContext fetchSourceContext = new FetchSourceContext(true, new String[]{"sex"}, Strings.EMPTY_ARRAY);
        getRequest.fetchSourceContext(fetchSourceContext)*/
        GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
        if (getResponse.isExists()) {
            System.out.println(getResponse);
            System.out.println(getResponse.getId());
            System.out.println(getResponse.getSource());
            System.out.println(getResponse.getSourceAsMap());
            UserTest userTest1 = entityConvert(getResponse.getSourceAsString(), UserTest.class);
            System.out.println(userTest1);
            UserTest userTest2 = entityConvert(getResponse.getSource(), UserTest.class);
            System.out.println(userTest2);
        }
    }

    @Test
    public void update() throws IOException {
        UpdateRequest updateRequest = new UpdateRequest("posts", "8");
        updateRequest.doc("sex", "女");
        UpdateResponse update = client.update(updateRequest, RequestOptions.DEFAULT);
        System.out.println(update);
    }

    @Test
    public void delete() throws IOException {
        DeleteRequest deleteRequest = new DeleteRequest("posts");
        DeleteResponse delete = client.delete(deleteRequest, RequestOptions.DEFAULT);
    }

    /**
     * 经过字段值查询
     * @throws IOException
     */
    @Test
    public void search() throws IOException {
        SearchRequest searchRequest = new SearchRequest("posts");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        //经过匹配某一字段查询
//        searchSourceBuilder.query(QueryBuilders.termQuery("name","董"));
        //选出指定结果字段
        searchSourceBuilder.fetchSource(new String[]{"id"},Strings.EMPTY_ARRAY);
        //对结果排序
//        searchSourceBuilder.sort(new FieldSortBuilder("id").order(SortOrder.DESC));
        //汇集结果
        searchSourceBuilder.aggregation(
                AggregationBuilders
                        .max("maxValue")//命名
                        .field("id"));//指定汇集的字段
        //查询全部
//        searchSourceBuilder.query(QueryBuilders.matchAllQuery());
        //从0开始
//        searchSourceBuilder.from(2).size(2);

        searchRequest.source(searchSourceBuilder);
        SearchResponse search = client.search(searchRequest, RequestOptions.DEFAULT);
        System.out.println(search);
    }

    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    private static class UserTest {
        private int id;
        private String name;
        private String sex;
        private Others others = new Others("132@qq.com", "199");
    }

    @Data
    @AllArgsConstructor
    private static class Others {
        private String email;
        private String phone;
    }

    /**
     * 实体对象转化为map
     * @param object
     * @return
     * @throws JsonProcessingException
     */
    static Map entityToMap(Object object) throws JsonProcessingException {
        Map map = entityConvert(object, HashMap.class);
        return map;
    }

    /**
     * 一个对象转化为另外一个有相同属性的对象
     * @param object
     * @param clazz
     * @param <T>
     * @return
     * @throws JsonProcessingException
     */
    static <T> T entityConvert(Object object, Class<T> clazz) throws JsonProcessingException {
        ObjectMapper objectMapper = new ObjectMapper();
        String s;
        if (object instanceof String) {
            s = String.valueOf(object);
        } else {
            s = objectMapper.writeValueAsString(object);
        }
        T t = objectMapper.readValue(s, clazz);
        return t;
    }
}