elasticsearch基本使用

1、maven引用
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.2.0</version>
        </dependency>

        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.2.0</version>
        </dependency>

2、ElasticsearchConfig.java

@Configuration
public class ElasticsearchConfig {

    @Bean
    public RestHighLevelClient restHighLevelClient() {
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.01", 9200, "http")));
        return restHighLevelClient;
    }
}

3、ContentService.java

@Service("contentService")
public class ContentService {

    @Autowired
    private RestHighLevelClient restHighLevelClient;

    public boolean parseContent(String keywords) throws Exception {
        List<Goods> contents = HtmlParserUtils.parseJD(keywords);

        BulkRequest bulkRequest = new BulkRequest();
        bulkRequest.timeout("2m");

        for (int i = 0; i < contents.size(); i++) {
            bulkRequest.add(new IndexRequest("jd_goods").source(JSON.toJSONString(contents.get(i)), XContentType.JSON));
        }

        BulkResponse bulk = restHighLevelClient.bulk(bulkRequest, RequestOptions.DEFAULT);
        return bulk.hasFailures();
    }

    public List<Map<String, Object>> searchPage(String keywords, int pageNo, int pageSize) throws Exception {
        if (pageNo <=1) {
            pageNo = 1;
        }
        SearchRequest searchRequest = new SearchRequest("jd_goods");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        // 分页
        sourceBuilder.from(pageNo);
        sourceBuilder.size(pageSize);
        // 精准匹配
        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("title", keywords);
        sourceBuilder.query(termQueryBuilder);
        sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));

        // 执行搜索
        searchRequest.source(sourceBuilder);
        SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
        // 解析结果
        List<Map<String, Object>> list = new ArrayList<>();
        for(SearchHit documentFields : searchResponse.getHits().getHits()) {
            list.add(documentFields.getSourceAsMap());
        }
        return list;
    }

    /**
     * 搜索高亮
     * @param keywords
     * @param pageNo
     * @param pageSize
     * @return
     * @throws Exception
     */
    public List<Map<String, Object>> searchPageHighlight(String keywords, int pageNo, int pageSize) throws Exception {
        if (pageNo <=1) {
            pageNo = 1;
        }
        SearchRequest searchRequest = new SearchRequest("jd_goods");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        // 分页
        sourceBuilder.from(pageNo);
        sourceBuilder.size(pageSize);
        // 精准匹配
        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("title", keywords);
        sourceBuilder.query(termQueryBuilder);
        sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));

        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.field("title");
        // 多个高亮显示
        highlightBuilder.requireFieldMatch(false);
        highlightBuilder.preTags("<span style='color:red'>");
        highlightBuilder.postTags("</span>");
        sourceBuilder.highlighter(highlightBuilder);

        // 执行搜索
        searchRequest.source(sourceBuilder);
        SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
        // 解析结果
        List<Map<String, Object>> list = new ArrayList<>();
        for(SearchHit hit : searchResponse.getHits().getHits()) {
            // 解析高亮的字段
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            HighlightField title = highlightFields.get("title");
            Map<String, Object> sourceMap = hit.getSourceAsMap();
            if (title != null) {
                Text[] fragments = title.fragments();
                String n_title = "";
                for (Text text : fragments) {
                    n_title = n_title + text;
                }
                // 高亮字段替换原来的内容即可
                sourceMap.put("title", n_title);
            }
            list.add(sourceMap);
        }
        return list;
    }

}