ElasticSearch（三）SpringBoot 整合ES

使用Java API

这种方式，官方已经明确表示在ES 7.0 版本中弃用 TransportClient 客户端，且在8.0 版本中完全移除它。

可以参考：https://blog.csdn.net/jacksonary/article/details/82729556

官方文档：https://www.elastic.co/guide/en/elasticsearch/client/index.html

ElasticSearch-Rest- client

9300 TCP

spring:data-elasticsearch:transport-api.jar

• SpringBoot 版本不同，transport-api.jar 不同，不能适配es版本

• 7.x 己经不建议使用，8以后就要废弃

9200: HTTP

• JesClient， 非官方，更新慢
• RestTemplate：模拟发 HTTP 请求，ES 很多操作需要自己封装，麻烦
• HttpClient：同上
• ElasticSearch-Rest- client :官方的RestClient 封装了ES操作，API层次分明，上手简单

最终我们需要使用Rest Client来和ES建立HTTP连接。

官方文档：https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-getting-started-maven.html

JAVA DOC：https://artifacts.elastic.co/javadoc/org/elasticsearch/client/elasticsearch-rest-high-level-client/7.17.3/index.html

到这的时候发现

所以准备手动更新es和kibana的版本。参考docker hub给出的版本。

出现的第一个错误。

https://github.com/medcl/elasticsearch-analysis-ik/releases找到8.1.2。

我无语。。。。

只有到8.1.2.。。。。。。。。无语死了😓

elasticsearch Tags | Docker Hub

去找8.1.2.

总结一下吧。

遇到的第一个错误

官方配置介绍：https://www.elastic.co/guide/en/kibana/current/settings.html

所以要看一下kibana的配置文件。

根据官网介绍需要改成自己虚拟机的地址。

起来了。

有发现kibana服务没起来，看了一下日志。

这种问题很常见。

可以看到我们之前的容器还占着。网上有好多教程，哈哈哈哈我打算避其锋芒，改端口。

# 清一下缓存
docker system prune 

至此更新完成。

与SpringBoot整合

官方文档：https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-getting-started-maven.html

导入依赖

    <properties>
        <java.version>1.8</java.version>
        <elasticsearch.version>7.17.3</elasticsearch.version>
    </properties>
<!--elasticsearch依赖-->
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.17.3</version>
</dependency>

编写配置

官方文档：https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-getting-started-initialization.html

给容器中注入一个RestHighLevelClient。

@Configuration
public class EsClientConfig {

    @Bean
    public RestHighLevelClient RestHighLevelClient() {
        
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.1.115", 9200, "http")
                ));
        return client;
    }
}

测试

如果有报错“datasource”，在启动类上添加：@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)

@SpringBootTest
public class EsclientApplicationTests {
    @Autowired
    RestHighLevelClient client;

    @Test
    public void test1() {
        System.out.println(client);
    }

}

测试增删改查的操作

官方文档：https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-document-index.html#java-rest-high-document-index-request

package com.uin.esclient;

@SpringBootTest
public class EsclientApplicationTests {
    @Autowired
    RestHighLevelClient client;

    @Test
    public void test1() {
        System.out.println(client);
    }

    /**
     * index Api
     */
    @Test
    public void test_index() throws IOException {
        //设置索引的名字
        IndexRequest indexRequest = new IndexRequest("users");
        //添加数据
        indexRequest.id("1");
        //indexRequest.source("username","uin","age","18","gender","男");

        //将User对象转化为JSON数据
        User user = new User();
        user.setUsername("uin");
        user.setGender("男");
        user.setAge(22);
        String s = JSON.toJSONString(user);

        indexRequest.source(s, XContentType.JSON);

        //执行保存数据分为：同步保存和异步保存

        IndexResponse index = client.index(indexRequest, EsClientConfig.COMMON_OPTIONS);
        //提取响应的数据
        System.out.println(index);

    }

    @Data
    class User {
        private String username;
        private String gender;
        private Integer age;
    }

    @Test
    public void test_search() throws IOException {
        //1.创建检索请求
        SearchRequest searchRequest = new SearchRequest();
        //2.指定要检索的索引
        searchRequest.indices("bank");
        //3.构建检索条件
        SearchSourceBuilder builder = new SearchSourceBuilder();
        //检索的条件
        builder.query(QueryBuilders.matchQuery("address", "mill"));
        //对年龄进行聚合
        TermsAggregationBuilder ageAgg = AggregationBuilders.terms("ageAgg")
                .field("age").size(10);
        builder.aggregation(ageAgg);
        //求出这些年龄分布的平均工资
        AvgAggregationBuilder banlanceAvg = AggregationBuilders.avg("banlanceAvg").field(
                "balance");
        builder.aggregation(banlanceAvg);
        //builder.from();
        //builder.size();
        //builder.sort();
        System.out.println("检索条件" + builder);

        //4.执行检索
        SearchResponse search = client.search(searchRequest, EsClientConfig.COMMON_OPTIONS);
        System.out.println(search.toString());

        //5.分析结果 将json数据转换成对象
        //获取所有命中到的数据
        SearchHits hits1 = search.getHits();
        //System.out.println(hits1);
        SearchHit[] hits = hits1.getHits();

        for (SearchHit hit : hits) {
            //Map<String, Object> asMap = hit.getSourceAsMap();
            String sourceAsString = hit.getSourceAsString();
            JsonRootBean bean = JSON.parseObject(sourceAsString, JsonRootBean.class);
            System.out.println("检索出来的对象：" + bean);
            //System.out.println(sourceAsString);
        }
        //Map map = JSON.parseObject(String.valueOf(search), Map.class);

        //6.获取分析之后的数据
        Aggregations aggregations = search.getAggregations();
        //aggregations.asList().forEach(aggregation -> System.out.println("当前聚合的名字" + aggregation
        // .getName()));
        Terms ageAgg1 = aggregations.get("ageAgg");
        if (ageAgg1!=null){
//            ageAgg1.getBuckets().forEach((Consumer<Terms.Bucket>) bucket -> {
//                String keyAsString = bucket.getKeyAsString();
//                System.out.println("年龄：" + keyAsString);
//            });
            for (Terms.Bucket bucket:ageAgg1.getBuckets()){
                String keyAsString = bucket.getKeyAsString();
                System.out.println("年龄：" + keyAsString);
            }
        }


        Avg banlanceAvg1 = aggregations.get("banlanceAvg");
        System.out.println("平均薪资："+banlanceAvg1.getValue());
    }

}