SpringBoot 如何整合 ES 实现 CRUD 操作

http.cors.enabled: true
http.cors.allow-origin: "*"

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

server:
 port: 8060

spring:
 elasticsearch:
 rest:
 uris: http://localhost:9200

import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;

import java.util.Date;

@Document(indexName = "article")
public class Article {

 @Id
 private String id;
 private String title;
 private String content;
 private Integer userId;
 private Date createTime;

 // ... igonre getters and setters
}

import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;

public interface ArticleRepository extends ElasticsearchRepository<Article, String> {

}

 @Autowired
 private ArticleRepository articleRepository;

 @GetMapping("{id}")
 public JsonResult findById(@PathVariable String id) {
 Optional<Article> article = articleRepository.findById(id);
 JsonResult jsonResult = new JsonResult(true);
 jsonResult.put("article", article.orElse(null));
 return jsonResult;
 }

 @DeleteMapping("{id}")
 public JsonResult delete(@PathVariable String id) {
 // 根据 id 删除
 articleRepository.deleteById(id);
 return new JsonResult(true, "删除成功");
 }

 @PostMapping("")
 public JsonResult save(Article article) {
 // 新增或更新
 String verifyRes = verifySaveForm(article);
 if (!StringUtils.isEmpty(verifyRes)) {
  return new JsonResult(false, verifyRes);
 }

 if (StringUtils.isEmpty(article.getId())) {
  article.setCreateTime(new Date());
 }

 Article a = articleRepository.save(article);
 boolean res = a.getId() != null;
 return new JsonResult(res, res ? "保存成功" : "");
 }

 private String verifySaveForm(Article article) {
 if (article == null || StringUtils.isEmpty(article.getTitle())) {
  return "标题不能为空";
 } else if (StringUtils.isEmpty(article.getContent())) {
  return "内容不能为空";
 }

 return null;
 }

 @Autowired
 private ElasticsearchRestTemplate elasticsearchRestTemplate;

 @Autowired
 ElasticsearchOperations elasticsearchOperations;

 @GetMapping("list")
 public JsonResult list(Integer currentPage, Integer limit) {
 if (currentPage == null || currentPage < 0 || limit == null || limit <= 0) {
  return new JsonResult(false, "请输入合法的分页参数");
 }
 // 分页列表查询
 // 旧版本的 Repository 中的 search 方法被废弃了。
 // 这里采用 ElasticSearchRestTemplate 或 ElasticsearchOperations 来进行分页查询

 JsonResult jsonResult = new JsonResult(true);
 NativeSearchQuery query = new NativeSearchQuery(new BoolQueryBuilder());
 query.setPageable(PageRequest.of(currentPage, limit));

 // 方法1：
 SearchHits<Article> searchHits = elasticsearchRestTemplate.search(query, Article.class);

 // 方法2：
 // SearchHits<Article> searchHits = elasticsearchOperations.search(query, Article.class);

 List<Article> articles = searchHits.getSearchHits().stream().map(SearchHit::getContent).collect(Collectors.toList());
 jsonResult.put("count", searchHits.getTotalHits());
 jsonResult.put("articles", articles);
 return jsonResult;
 }

 @GetMapping("scroll")
 public JsonResult scroll(String scrollId, Integer size) {
 // 滚动查询 scroll api
 if (size == null || size <= 0) {
  return new JsonResult(false, "请输入每页查询数");
 }
 NativeSearchQuery query = new NativeSearchQuery(new BoolQueryBuilder());
 query.setPageable(PageRequest.of(0, size));
 SearchHits<Article> searchHits = null;
 if (StringUtils.isEmpty(scrollId)) {
  // 开启一个滚动查询，设置该 scroll 上下文存在 60s
  // 同一个 scroll 上下文，只需要设置一次 query（查询条件）
  searchHits = elasticsearchRestTemplate.searchScrollStart(60000, query, Article.class, IndexCoordinates.of("article"));
  if (searchHits instanceof SearchHitsImpl) {
  scrollId = ((SearchHitsImpl) searchHits).getScrollId();
  }
 } else {
  // 继续滚动
  searchHits = elasticsearchRestTemplate.searchScrollContinue(scrollId, 60000, Article.class, IndexCoordinates.of("article"));
 }

 List<Article> articles = searchHits.getSearchHits().stream().map(SearchHit::getContent).collect(Collectors.toList());
 if (articles.size() == 0) {
  // 结束滚动
  elasticsearchRestTemplate.searchScrollClear(Collections.singletonList(scrollId));
  scrollId = null;
 }

 if (scrollId == null) {
  return new JsonResult(false, "已到末尾");
 } else {
  JsonResult jsonResult = new JsonResult(true);
  jsonResult.put("count", searchHits.getTotalHits());
  jsonResult.put("size", articles.size());
  jsonResult.put("articles", articles);
  jsonResult.put("scrollId", scrollId);
  return jsonResult;
 }

 }