饥渴计科极客杰铿 通过本文主要向大家介绍了elastisearch,java搜索引擎,java模板引擎,java流程引擎,java 工作流引擎等相关知识,希望对您有所帮助,也希望大家支持linkedu.com www.linkedu.com
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
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.4.0.zip
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2.解压
unzip elasticsearch-5.4.0.zip</div>
3.运行
elasticsearch-5.4.0/bin/elasticsearch</div>
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</div>
将22和23行的栈堆大小改为512M
-Xms512M -Xmx512M</div>
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'</div>
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"
}
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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>
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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();
}
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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);
}
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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);
}
}
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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());
}
}
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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);
}
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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);
}
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7.排序
/** * 排序