spring整合Elasticsearch

Posted 2023-03-01 晓宜

• 引入依赖

- spring-boot-starter-data-elasticsearch

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
		</dependency>

• 配置Elasticsearch

解决netty启动冲突问题

    @PostConstruct
    public void init() 
        // 解决netty启动冲突问题
        // see Netty4Utils.setAvailableProcessors()
        System.setProperty("es.set.netty.runtime.available.processors", "false");
    

- cluster-name、cluster-nodes

# ElasticsearchProperties
spring.data.elasticsearch.cluster-name=nowcoder
spring.data.elasticsearch.cluster-nodes=127.0.0.1:9300

• Spring Data Elasticsearch

Elasticsearch有两种方式可以调用：

- ElasticsearchTemplate

案例：

  
    @Test
    public void testSearchByTemplate() 
        SearchQuery searchQuery = new NativeSearchQueryBuilder()
                .withQuery(QueryBuilders.multiMatchQuery("互联网寒冬", "title", "content"))
                .withSort(SortBuilders.fieldSort("type").order(SortOrder.DESC))
                .withSort(SortBuilders.fieldSort("score").order(SortOrder.DESC))
                .withSort(SortBuilders.fieldSort("createTime").order(SortOrder.DESC))
                .withPageable(PageRequest.of(0, 10))
                .withHighlightFields(
                        new HighlightBuilder.Field("title").preTags("<em>").postTags("</em>"),
                        new HighlightBuilder.Field("content").preTags("<em>").postTags("</em>")
                ).build();

        Page<DiscussPost> page = elasticTemplate.queryForPage(searchQuery, DiscussPost.class, new SearchResultMapper() 
            @Override
            public <T> AggregatedPage<T> mapResults(SearchResponse response, Class<T> aClass, Pageable pageable) 
                SearchHits hits = response.getHits();
                if (hits.getTotalHits() <= 0) 
                    return null;
                

                List<DiscussPost> list = new ArrayList<>();
                for (SearchHit hit : hits) 
                    DiscussPost post = new DiscussPost();

                    String id = hit.getSourceAsMap().get("id").toString();
                    post.setId(Integer.valueOf(id));

                    String userId = hit.getSourceAsMap().get("userId").toString();
                    post.setUserId(Integer.valueOf(userId));

                    String title = hit.getSourceAsMap().get("title").toString();
                    post.setTitle(title);

                    String content = hit.getSourceAsMap().get("content").toString();
                    post.setContent(content);

                    String status = hit.getSourceAsMap().get("status").toString();
                    post.setStatus(Integer.valueOf(status));

                    String createTime = hit.getSourceAsMap().get("createTime").toString();
                    post.setCreateTime(new Date(Long.valueOf(createTime)));

                    String commentCount = hit.getSourceAsMap().get("commentCount").toString();
                    post.setCommentCount(Integer.valueOf(commentCount));

                    // 处理高亮显示的结果
                    HighlightField titleField = hit.getHighlightFields().get("title");
                    if (titleField != null) 
                        post.setTitle(titleField.getFragments()[0].toString());
                    

                    HighlightField contentField = hit.getHighlightFields().get("content");
                    if (contentField != null) 
                        post.setContent(contentField.getFragments()[0].toString());
                    

                    list.add(post);
                

                return new AggregatedPageImpl(list, pageable,
                        hits.getTotalHits(), response.getAggregations(), response.getScrollId(), hits.getMaxScore());
            
        );

        System.out.println(page.getTotalElements());
        System.out.println(page.getTotalPages());
        System.out.println(page.getNumber());
        System.out.println(page.getSize());
        for (DiscussPost post : page) 
            System.out.println(post);
        
    

- ElasticsearchRepository

首先写一个接口扩展 ElasticsearchRepository

@Repository
public interface DiscussPostRepository extends ElasticsearchRepository<DiscussPost, Integer> 

这里我们可以直接调用相关接口实现增删改查的功能

案例：

    @Test
    public void testInsert() 
        for(int i = 109; i <= 280; i++)
        discussRepository.save(discussMapper.selectDiscussPostById(i));
    

    @Test
    public void testInsertList() 
        discussRepository.saveAll(discussMapper.selectDiscussPosts(101, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(102, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(103, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(111, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(112, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(131, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(132, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(133, 0, 100, 0));
        discussRepository.saveAll(discussMapper.selectDiscussPosts(134, 0, 100, 0));
    

    @Test
    public void testUpdate() 
        DiscussPost post = discussMapper.selectDiscussPostById(231);
        post.setContent("我是新人,使劲灌水.");
        discussRepository.save(post);
    

    @Test
    public void testDelete() 
         discussRepository.deleteById(319);
         discussRepository.deleteById(320);
         discussRepository.deleteById(321);
//        discussRepository.deleteAll();
    

    @Test
    public void testSearchByRepository() 
        SearchQuery searchQuery = new NativeSearchQueryBuilder()
                .withQuery(QueryBuilders.multiMatchQuery("互联网寒冬", "title", "content"))
                .withSort(SortBuilders.fieldSort("type").order(SortOrder.DESC))
                .withSort(SortBuilders.fieldSort("score").order(SortOrder.DESC))
                .withSort(SortBuilders.fieldSort("createTime").order(SortOrder.DESC))
                .withPageable(PageRequest.of(0, 10))
                .withHighlightFields(
                        new HighlightBuilder.Field("title").preTags("<em>").postTags("</em>"),
                        new HighlightBuilder.Field("content").preTags("<em>").postTags("</em>")
                ).build();

        // elasticTemplate.queryForPage(searchQuery, class, SearchResultMapper)
        // 底层获取得到了高亮显示的值, 但是没有返回.

        Page<DiscussPost> page = discussRepository.search(searchQuery);
        System.out.println(page.getTotalElements());
        System.out.println(page.getTotalPages());
        System.out.println(page.getNumber());
        System.out.println(page.getSize());
        for (DiscussPost post : page) 
            System.out.println(post);