本篇文章主要介绍了Java使用强大的Elastisearch搜索引擎实例代码，具有一定的参考价值，有兴趣的可以了解一下
Elastisearch是一个很强大,易用的搜索引擎
在系统上运行Elastisearch只需以下几步
1.下载Elastisearch
代码如下:
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.4.0.zip
2.解压
unzip elasticsearch-5.4.0.zip
3.运行
elasticsearch-5.4.0/bin/elasticsearch
这时有可能会直接被Killed掉，因为内存溢出（OOM），elastisearch占用的内存非常大，所以在内存比较小的服务器上运行要先修改jvm的内存大小
vi elasticsearch-5.4.0/config/jvm.options
将22和23行的栈堆大小改为512M
-Xms512M-Xmx512M
如果重新启动后还是killed就再改小一点
4.测试是否成功
curl 'http://localhost:9200/?pretty'
你能看到以下返回信息:
{ "status": 200, "name": "Shrunken Bones", "version": { "number": "1.4.0", "lucene_version": "4.10" }, "tagline": "You Know, for Search"}
则表明启动成功
接下来我们用Java的API来操作Elasticsearch
首先是导入elastisearch和log4j的包
POM
<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.jk</groupId> <artifactId>ElasticsearchExample</artifactId> <version>1.0-SNAPSHOT</version> <dependencies> <dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>transport</artifactId> <!--用哪个版本就填什么--> <version>5.4.0</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.7</version> </dependency> </dependencies></project>
以下是常用的几种操作
1.创建client
Client client = null; try { client = new PreBuiltTransportClient(Settings.EMPTY) .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300)); } catch (Exception e) { e.printStackTrace(); }
2.创建索引
/** * 创建索引，有则先删除 * @param client */ private static void recreateIndex(Client client) { if (client.admin().indices().prepareExists(index).execute().actionGet() .isExists()) { DeleteIndexResponse deleteIndexResponse = client.admin().indices() .delete(new DeleteIndexRequest(index)).actionGet(); System.out.println("delete index :"); System.out.println(deleteIndexResponse); } CreateIndexResponse createIndexResponse = client.admin().indices() .prepareCreate(index).execute().actionGet(); System.out.println("create index :"); System.out.println(createIndexResponse); }
3.插入数据
/** * 插入数据 * @param client */ @SuppressWarnings({"rawtypes", "unchecked"}) private static void doIndex(final Client client) { Map s11 = new LinkedHashMap(); s11.put("title", "Think in java"); s11.put("origin", "美国"); s11.put("description", "初级java开发人员必读的书"); s11.put("author", "Bruce Eckel"); s11.put("price", 108); Map s12 = new LinkedHashMap(); s12.put("title", "Head First Java"); s12.put("origin", "英国"); s12.put("description", "java入门教材"); s12.put("author", "Kathy Sierra"); s12.put("price", 54); Map s21 = new LinkedHashMap(); s21.put("title", "Design Pattern"); s21.put("origin", "法国"); s21.put("description", "程序员不得不读的设计模式"); s21.put("author", "Kathy Sierra"); s21.put("price", 89); Map s22 = new LinkedHashMap(); s22.put("title", "黑客与画家"); s22.put("origin", "法国"); s22.put("description", "读完之后脑洞大开"); s22.put("author", "Paul Graham"); s22.put("price", 35); BulkResponse bulkResponse = client .prepareBulk() .add(client.prepareIndex(index, type).setId("11").setSource(s11).setOpType(IndexRequest.OpType.INDEX).request()) .add(client.prepareIndex(index, type).setId("12").setSource(s12).setOpType(IndexRequest.OpType.INDEX).request()) .add(client.prepareIndex(index, type).setId("21").setSource(s21).setOpType(IndexRequest.OpType.INDEX).request()) .add(client.prepareIndex(index, type).setId("22").setSource(s22).setOpType(IndexRequest.OpType.INDEX).request()) .execute().actionGet(); if (bulkResponse.hasFailures()) { System.err.println("index docs ERROR:" + bulkResponse.buildFailureMessage()); } else { System.out.println("index docs SUCCESS:"); System.out.println(bulkResponse); } }
4.查询所有
/** * 查询所有 */ private static void searchAll(Client client) { SearchResponse response = client.prepareSearch(index) .setQuery(QueryBuilders.matchAllQuery()) .setExplain(true).execute().actionGet(); System.out.println("searchAll : "); for (SearchHit searchHit : response.getHits()) { System.out.println("********"); System.out.println(searchHit.getSource()); } }
5.关键词查询
/** * 关键词查询 * * @param client */ private static void searchKeyWord(Client client) { SearchResponse response = client.prepareSearch(index) //查询所有字段匹配关键字 .setQuery(QueryBuilders.matchQuery("_all", "法国")) //设置最小匹配程度// .setQuery(QueryBuilders.matchQuery("_all", "法国").minimumShouldMatch("100%")) .execute().actionGet(); System.out.println("searchKeyWord : "); System.out.println(response); }
6.数值范围过滤
/** * 数值范围过滤 * * @param client */ private static void searchRange(Client client) { SearchResponse response = client.prepareSearch(index). //大于80，小于100 setQuery(QueryBuilders.rangeQuery("price").gt(80).lt(100)) .execute() .actionGet(); System.out.println("searchRange : "); System.out.println(response); }
7.排序
/** * 排序 * * @param client */ private static void searchOrdered(Client client) { SearchResponse response = client.prepareSearch(index) .setQuery(QueryBuilders.matchAllQuery()) //根据价格降序排序 .addSort(SortBuilders.fieldSort("price") .order(SortOrder.DESC)).execute().actionGet(); System.out.println("searchOrdered : "); System.out.println(response); }
8.高亮关键字
/** * 高亮关键字 * @param client */ private static void searchHightlight(Client client) { //高亮多个字段 HighlightBuilder highlightBuilder = new HighlightBuilder(); highlightBuilder.field("title"); highlightBuilder.field("description"); SearchResponse response = client.prepareSearch(index) //单条件匹配，高亮时只能高亮该字段// .setQuery(QueryBuilders.matchQuery("title", "java")) //多条件匹配，高亮时只能高亮多个字段 .setQuery(QueryBuilders.multiMatchQuery("开发人员必读", "title", "description")) .highlighter(highlightBuilder) .execute() .actionGet(); System.out.println("searchHightlight : "); System.out.println(response); }
9.根据id查找
/** * 根据id查找 * @param client */ private static void findById(final Client client) { String id="12"; GetResponse response = client.prepareGet(index, type, id).get(); System.out.println("findById"); System.out.println(response); }
10.删除
/** * 删除 * @param client */ private static void deleteById(Client client) { String id="12"; DeleteResponse response = client.prepareDelete(index, type, id).get(); }
11.更新
/** * 更新 * @param client */ private static void updateById(Client client) { try { String id="11"; client.prepareUpdate(index, type, id) .setDoc(jsonBuilder() .startObject() .field("title", "白鹿原") .endObject()) .get(); } catch (IOException e) { e.printStackTrace(); } }
以上就是强大的Elastisearch搜索引擎在Java中使用的实例代码的详细内容，更多请关注其它相关文章！
那么，不如我们礼貌地保持相对距离，不至于太冷，不至于太痛。
