其他
Elasticsearch就是这么简单
一、前言
最近有点想弄一个站内搜索的功能，之前学过了Lucene，后来又听过Solr这个名词。接着在了解全文搜索的时候就发现了Elasticsearch这个，他也是以Lucene为基础的。
我去搜了几篇Elasticsearch教程，发现很多都是基于linux的，但我linux耍得并不熟，很少用。仅仅会一些简单的命令，等真正去用到linux的时候再慢慢啃吧。
于是发现了一篇写得很好的教程：
http://blog.csdn.net/laoyang360/article/details/52244917
首先是对Elasticsearch的安装，上面那篇教程也有说，并且给出了一键安装的脚本。这里就用来记录我个人的安装历程吧。
PS：2018年3月22日18:58:12更新：这里我已经不建议在Windows下装Elasticsearch了，因为装起来还是麻烦，也有一堆的小问题~(后面也有在Linux下配置Elasticsearch的过程，建议用linux环境下学习Elasticsearch(要是学生建议去买个服务器，有优惠的),实在不想出钱，用虚拟机也行~
二、Windows下安装Elasticsearch(不建议)
2.1安装Elasticsearch
安装Elasticsearch以window服务的方式来运行，它的给出的版本是2.3.3。于是我也去安装2.3.3了。
在官网上可以在搜索框中查找对应的版本
要以windows服务的方式运行，教程给出的链接已经挂了。我搜到了一篇
http://www.cnblogs.com/viaiu/p/5715200.html
2.2安装head
安装head插件就很简单了，切换到对应的目录下，使用如下命令：
plugin install mobz/elasticsearch-head
2.3安装kibana和Logstash插件以服务形式运行
给出的连接是stackOverFlow下的提问，还有youtobe的视频。stackOverFlow并不能解决我安装过程的问题，youtobe我没联外网，也进不去。
后来，我又找到了一篇教程，也十分顺利：
https://segmentfault.com/a/1190000010741203#articleHeader2
Logstash下载的版本是：2.3.3与Elasticsearch对应起来。
下载kibana的版本是：4.5.0
能够出现下面这种情况，说明安装成功
2.4安装Shield
plugin install license
plugin install shield
重启，接着执行:
添加管理员
bin/shield/esusers useradd adminName -r admin
为kibana添加用户
esusers useradd kibanaserver -r kibana4_server
在其配置上(kibana.yml)添加:
kibana_elasticsearch_username: kibanaserver #Kibana服务将用这个用户名访问ElasticSearch服务器。
kibana_elasticsearch_password: zhongfucheng #密码
只有配置了kibanaserver账户、才能登陆进去
2.5安装分词器
这次教程给出的连接就用上了，我截图主要的：
ik分词器的版本是1.9.3。文章给出的是以mvn的方式打包下载。因此在github中我们下载resouce类型的。
解压的时候是在zip解压到当前文件上，把conf的数据拿过去是将其源文件拿过去(不包括文件夹!)
2.6拼音分词器
前面下载了中文分词器，后边在看教程的时候也发现了拼音分词器，拼音分词器的安装和中文分词器安装的时候很类似
对应Elasticsearch2.3.3版本的拼音分词器版本为：1.7.3
Windows下装Elasticsearch到此就结束了。
三、Linux下安装Elasticsearch
这是我搭建一个项目时候的笔记，
3.1下载Elasticsearch
Elasticserach的下载还是非常方便的，提供搜索来进行下载。这里我就不贴链接了。直接去官网找就行了。
下载了2.3.3版本，因为我在windows开发的时候也是下载2.3.3版本的，就为了保持一致吧。
3.2安装Elasticsearch
tar -xzvf elasticsearch-2.3.3.tar.gz
切换到bin目录下执行就行了…
需要这样执行elasticsearch，如果使用的是root用户的话
./elasticsearch -d -Des.insecure.allow.root=true
现在使用下面的语句，是可以获取得到信息的
curl -X GET 'http://localhost:9200'
想要通过外网来访问的话，那么就需要修改配置文件了，参考链接http://blog.csdn.net/u012599988/article/details/51767183
还要在ESC服务器上开放端口才能访问：
3.2.1下载head插件
在下载head插件的时候，需要修改elasticsearch的用户和组，否则它就不让你下载。命令如下
添加用户和组
groupadd elasticsearch
useradd elasticsearch -g elasticsearch -p 123456
修改文件夹权限
chown -R elasticsearch:elasticsearch elasticsearch-2.3.3
弄完之后就可以执行命令下载head插件了。
./plugin install mobz/elasticsearch-head
下载完head插件后，不要立马下载shield插件，首先在head插件上创建一个索引!
否则，当下载完shield插件、再访问head插件的话，就无法连接节点了!
这搞了我好长的时间才弄好!!!!!网上也有很多人遇到过这种情况，却没什么好的回答。都在说配置文件上的事情。
我是通过在github中别人提出的issue中找到答案的。参考:https://github.com/mobz/elasticsearch-head/issues/191#issuecomment-132636493
记住了，先在head插件中创建索引、再下载shield插件，否则无法连接head插件!
3.2.2下载权限shield
我在windows下开发是有下载shiled，为了保持一致，我也下载吧。
输入命令：
plugin install license
plugin install shield
下载完就配置一个管理员用户
bin/shield/esusers useradd adminName -r admin
如果文章有错的地方欢迎指正，大家互相交流。习惯在微信看技术文章，想要获取更多的Java资源的同学，可以关注微信公众号:Java3y
四、REST API
在前面一章中已经下载了Elasticsearch和它常用的各种插件了。了解相关的概念后，我们就应该动手弄一弄Elasticsearch是怎么用的。
参考链接：
http://blog.csdn.net/laoyang360/article/details/52244917
我是跟着这个教程大致把REST API走了一下，也渐渐了解了Elasticsearch的知识点了。
http://www.yiibai.com/elasticsearch/elasticsearch_installation.html
五、JAVA API
我们毕竟是使用Java的，因此得知道Elasticsearch和Java是怎么连接的。我找了几篇教程：
http://www.cnblogs.com/wenbronk/p/6383194.html
http://www.cnblogs.com/tutu21ybz/p/6835178.html
后来找到了一篇比较系统的教程，推荐这个：
http://blog.csdn.net/napoay/article/details/51707023
自己也跟着教程写了Demo，其中也出了不少错误。贴上代码：
import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
import org.elasticsearch.action.admin.indices.close.CloseIndexResponse;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexResponse;
import org.elasticsearch.action.admin.indices.exists.indices.IndicesExistsRequest;
import org.elasticsearch.action.admin.indices.exists.indices.IndicesExistsResponse;
import org.elasticsearch.action.admin.indices.exists.types.TypesExistsResponse;
import org.elasticsearch.action.admin.indices.open.OpenIndexResponse;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.deletebyquery.DeleteByQueryAction;
import org.elasticsearch.action.deletebyquery.DeleteByQueryRequestBuilder;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.get.MultiGetItemResponse;
import org.elasticsearch.action.get.MultiGetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.cluster.metadata.MappingMetaData;
import org.elasticsearch.common.collect.ImmutableOpenMap;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.script.Script;
import org.elasticsearch.script.ScriptService;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.shield.ShieldPlugin;
import org.junit.Test;
import java.io.*;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.List;
import java.util.concurrent.ExecutionException;
import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
import static org.elasticsearch.index.query.QueryBuilders.termQuery;
import org.elasticsearch.client.transport.TransportClient;
/**
* Created by ozc on 2017/11/5.
*/
public class ElasticsearchDemo {
/**
* 创建
* @throws UnknownHostException
*/
public void CreateIndex() throws UnknownHostException {
//连接客户端
Client client = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
//将数据转成json字符串，用集合装载起来
List<String> jsonData = DataFactory.getInitJsonData();
//创建blog索引、article类型、数据是上边的json字符串
for (int i = 0; i < jsonData.size(); i++) {
IndexResponse response = client.prepareIndex("blog", "article","1").setSource(jsonData.get(i)).get();
if (response.isCreated()) {
System.out.println("创建成功!");
}
}
client.close();
}
/**
* 查询
* @throws UnknownHostException
*/
public void selectIndex() throws UnknownHostException {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
//查询title字段中包含hibernate关键字的文档
QueryBuilder qb1 = termQuery("title", "hibernate");
//查询title字段或content字段中包含git关键字的文档:
QueryBuilder qb2= QueryBuilders.multiMatchQuery("git", "title","content");
SearchResponse response = client.prepareSearch("blog").setTypes("article").setQuery(qb2).execute()
.actionGet();
SearchHits hits = response.getHits();
if (hits.totalHits() > 0) {
for (SearchHit hit : hits) {
System.out.println("score:"+hit.getScore()+":\t"+hit.getSource());// .get("title")
}
} else {
System.out.println("搜到0条结果");
}
}
/**
* 使用updateRequest更新
* @throws IOException
* @throws ExecutionException
* @throws InterruptedException
*/
public void update1() throws IOException, ExecutionException, InterruptedException {
//连接客户端
Client client = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
UpdateRequest uRequest = new UpdateRequest();
uRequest.index("blog");
uRequest.type("article");
uRequest.id("1");
uRequest.doc(jsonBuilder().startObject().field("content", "学习目标 掌握java泛型的产生意义ssss").endObject());
client.update(uRequest).get();
}
/**
* 使用脚本更新，需要更改配置文件【我不喜欢用】
* @throws IOException
* @throws ExecutionException
* @throws InterruptedException
*/
public void update2() throws IOException, ExecutionException, InterruptedException {
//连接客户端
Client client = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
client.prepareUpdate("blog", "article", "1")
.setScript(new Script("ctx._source.title = \"git入门\"", ScriptService.ScriptType.INLINE, null, null))
.get();
}
/**
* 使用doc更新
* @throws IOException
* @throws ExecutionException
* @throws InterruptedException
*/
public void update3() throws IOException, ExecutionException, InterruptedException {
//连接客户端
Client client = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
client.prepareUpdate("blog", "article", "1")
.setDoc(jsonBuilder().startObject().field("content", "SVN与Git对比222222。。。").endObject()).get();
}
/**
* 使用updateRequest更新、能够新增新字段
* @throws IOException
* @throws ExecutionException
* @throws InterruptedException
*/
public void update4() throws IOException, ExecutionException, InterruptedException {
//连接客户端
Client client = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
UpdateRequest updateRequest = new UpdateRequest("blog", "article", "1")
.doc(jsonBuilder().startObject().field("commet", "0").endObject());
client.update(updateRequest).get();
}
/**
* 使用UpdateRequest更新， 如果文档不存在则创建新的索引
* @throws IOException
* @throws ExecutionException
* @throws InterruptedException
*/
public void update5() throws IOException, ExecutionException, InterruptedException {
//连接客户端
Client client = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
IndexRequest indexRequest = new IndexRequest("blog", "article", "10").source(jsonBuilder().startObject()
.field("title", "Git安装10").field("content", "学习目标 git。。。10").endObject());
UpdateRequest uRequest2 = new UpdateRequest("blog", "article", "10").doc(
jsonBuilder().startObject().field("title", "Git安装").field("content", "学习目标 git。。。").endObject())
.upsert(indexRequest);
client.update(uRequest2).get();
}
/**
* 删除具体的索引值
* @throws IOException
* @throws ExecutionException
* @throws InterruptedException
*/
public void deleteSpecificIndex() throws IOException, ExecutionException, InterruptedException {
//连接客户端
Client client = TransportClient.builder().build()
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
DeleteResponse dResponse = client.prepareDelete("blog", "article", "10").execute()
.actionGet();
if (dResponse.isFound()) {
System.out.println("删除成功");
} else {
System.out.println("删除失败");
}
}
/**
* 根据index名称 删除整个索引库
* @throws IOException
* @throws ExecutionException
* @throws InterruptedException
*/
public void deleteIndex() throws IOException, ExecutionException, InterruptedException {
//要删除索引库的名字
String indexName = "zhognfucheng";
if (!isIndexExists(indexName)) {
System.out.println(indexName + " not exists");
} else {
Client client = TransportClient.builder().build().addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"),
9300));
DeleteIndexResponse dResponse = client.admin().indices().prepareDelete(indexName)
.execute().actionGet();
if (dResponse.isAcknowledged()) {
System.out.println("delete index "+indexName+" successfully!");
}else{
System.out.println("Fail to delete index "+indexName);
}
}
}
// 创建索引库
public void createIndex() {
//要创建索引库的名称
String indexName = "shcool";
try {
Client client = TransportClient.builder().build().addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
// 创建索引库
if (isIndexExists(indexName)) {
System.out.println("Index " + indexName + " already exits!");
} else {
CreateIndexRequest cIndexRequest = new CreateIndexRequest(indexName);
CreateIndexResponse cIndexResponse = client.admin().indices().create(cIndexRequest)
.actionGet();
if (cIndexResponse.isAcknowledged()) {
System.out.println("create index successfully！");
} else {
System.out.println("Fail to create index!");
}
}
} catch (UnknownHostException e) {
e.printStackTrace();
}
}
/**
* 批量从Elasticsearch导出json到文件中
*/
public void ElasticSearchBulkOut() {
try {
//初始化
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch").build();// cluster.name在elasticsearch.yml
//连接客户端
Client client = TransportClient.builder().settings(settings).build()
.addTransportAddress(new InetSocketTransportAddress(
InetAddress.getByName("127.0.0.1"), 9300));
//匹配所有查询
QueryBuilder qb = QueryBuilders.matchAllQuery();
SearchResponse response = client.prepareSearch("blog")
.setTypes("article").setQuery(qb)
.execute().actionGet();
//获取命中记录
SearchHits resultHits = response.getHits();
//遍历命中记录，写到文件中
File article = new File("C:\\ElasticsearchDemo\\src\\java\\file\\bulk.txt");
FileWriter fw = new FileWriter(article);
BufferedWriter bfw = new BufferedWriter(fw);
if (resultHits.getHits().length == 0) {
System.out.println("查到0条数据!");
} else {
for (int i = 0; i < resultHits.getHits().length; i++) {
String jsonStr = resultHits.getHits()[i]
.getSourceAsString();
System.out.println(jsonStr);
bfw.write(jsonStr);
bfw.write("\n");
}
}
bfw.close();
fw.close();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 批量导入到Elasticsearch中
*/
public void ElasticSearchBulkInput() {
try {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch").build();// cluster.name在elasticsearch.yml中配置
Client client = TransportClient.builder().settings(settings).build()
.addTransportAddress(new InetSocketTransportAddress(
InetAddress.getByName("127.0.0.1"), 9300));
File article = new File("C:\\ElasticsearchDemo\\src\\java\\file\\bulk.txt");
FileReader fr=new FileReader(article);
BufferedReader bfr=new BufferedReader(fr);
String line = null;
BulkRequestBuilder bulkRequest=client.prepareBulk();
int count=0;
while((line=bfr.readLine())!=null){
bulkRequest.add(client.prepareIndex("test","article").setSource(line));
if (count%10==0) {
bulkRequest.execute().actionGet();
}
count++;
//System.out.println(line);
}
bulkRequest.execute().actionGet();
bfr.close();
fr.close();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 根据名称判断索引是否存在
* @param indexName
* @return
*/
public boolean isIndexExists(String indexName) {
boolean flag = false;
try {
Client client = TransportClient.builder().build().addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
IndicesExistsRequest inExistsRequest = new IndicesExistsRequest(indexName);
//下面可判断多个索引名称是否存在
//IndicesExistsResponse indexResponse = client.admin().indices().prepareExists("blog","blog1").execute().actionGet();
IndicesExistsResponse inExistsResponse = client.admin().indices()
.exists(inExistsRequest).actionGet();
if (inExistsResponse.isExists()) {
flag = true;
} else {
flag = false;
}
} catch (UnknownHostException e) {
e.printStackTrace();
}
return flag;
}
/**
* 删除type下的所有文档
* 也就是类似关系型数据库中根据表删除所有记录
*
* ps（需要下载插件plugin install delete-by-query）和导入pom包
*
* ps(使用的是windows服务的方式运行Elastic，因此需要在bin目录下的使用service重启，不然就会报空指针异常！
*/
public void deleteByQuery() throws UnknownHostException {
Client client = TransportClient.builder().build().addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
String deletebyquery = "{\"query\": {\"match_all\": {}}}";
DeleteByQueryRequestBuilder response = new DeleteByQueryRequestBuilder(client,DeleteByQueryAction.INSTANCE);
response.setIndices("blog").setTypes("article").setSource(deletebyquery)
.execute()
.actionGet();
}
//-------------------------------------------------------------------
/**
* Java三层嵌套查询，我感觉是用得很少的。贴个链接把：
* http://blog.csdn.net/napoay/article/details/52060659
* <p>
* 搜索有相同父id的子文档，我也感觉用得少。贴个链接吧：
* http://blog.csdn.net/napoay/article/details/52118408
*
* 集群配置，现在用不上。贴个链接吧：
* http://blog.csdn.net/napoay/article/details/52202877
*/
//-------------------------------------------------------------------
/**
* 删除index为blog、类型为article、id为1的索引中的id属性
* (需要在配置文件中添加以下内容），否则会出现异常
*
* script.inline: on
script.indexed: on
script.engine.groovy.inline.aggs: on
*
* @throws UnknownHostException
*/
public void deleteField() throws UnknownHostException {
Client client = TransportClient.builder().build().addTransportAddress(
new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
client.prepareUpdate("blog", "article", "1").setScript(new Script("ctx._source.remove(\"title\")",ScriptService.ScriptType.INLINE, null, null)).get();
//删除属性中的属性
//client.prepareUpdate("test", "document", "1").setScript(new Script( "ctx._source.processInstance.remove(\"id\")",ScriptService.ScriptType.INLINE, null, null)).get();
}
/**
* 添加了Elasticsearch安全插件以后，连接cliet的方式就要改变了。
*
* 网站给的maven坐标根本找不到，只能下载了个jar包用了。
*
* 配置了Elasticsearch认证以后，kibana也需要配置，不然进不去的。
*
* 链接：
* http://blog.csdn.net/sd4015700/article/details/50427852
*
* 当前配置的Elasticsearch zhongfucheng:zhongfucheng
* 当前配置的kibana kibanaserver:zhongfucheng (ps:此部分还需要修改配置文件，详情看上边的连接)
*
*/
public void changeClient() throws UnknownHostException {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
System.out.println(client);
}
/**
* 判断类型是否存在
* @throws UnknownHostException
*/
public void isTypeExists() throws UnknownHostException {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
// bolg是index、article是类型
TypesExistsResponse typeResponse = client.admin().indices()
.prepareTypesExists("blog").setTypes("article")
.execute().actionGet();
System.out.println(typeResponse.isExists());
}
/**
* 关闭索引
*/
public void closeIndex() throws UnknownHostException {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
CloseIndexResponse cIndexResponse = client.admin().indices().prepareClose("shcool")
.execute().actionGet();
if (cIndexResponse.isAcknowledged()) {
System.out.println("关闭索引成功");
}
}
/**
* 打开索引
* @throws UnknownHostException
*/
public void openIndex() throws UnknownHostException {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
OpenIndexResponse oIndexResponse = client.admin().indices()
.prepareOpen("shcool")
.execute().actionGet();
System.out.println(oIndexResponse.isAcknowledged());
}
/**
* 获取文档的集合
* 可以获取同一索引、同一类型、不同id的文档集合
* 也可以获取不同索引、不同类型、不同id的文档集合
*/
public void getDocCollection() throws UnknownHostException {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
MultiGetResponse multiGetItemResponses = client.prepareMultiGet()
.add("blog", "article", "1") //注释1
//.add("twitter", "tweet", "2", "3", "4") //注释2
.add("test", "article", "AV-K5x1NAQtVzQCf247Q") //注释3
.get();
for (MultiGetItemResponse itemResponse : multiGetItemResponses) { //注释4
GetResponse response = itemResponse.getResponse();
if (response.isExists()) { //注释5
String json = response.getSourceAsString(); //注释6
System.out.println(json);
}
}
/**
注释1: 通过单一的ID获取一个文档.
注释2：传入多个id，从相同的索引名/类型名中获取多个文档.
注释3：可以同时获取不同索引中的文档.
注释4：遍历结果集.
注释5：检验文档是否存在.
注释6：获取文档源.
*/
}
/**
* 获取索引下每个Type和Mapping
* @throws IOException
*/
public void getIndexTypeAndMapping() throws IOException {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
ImmutableOpenMap<String, MappingMetaData> mappings = client.admin().cluster().prepareState().execute()
.actionGet().getState().getMetaData().getIndices().get("blog").getMappings();
for (ObjectObjectCursor<String, MappingMetaData> cursor : mappings) {
System.out.println(cursor.key); // 索引下的每个type
System.out.println(cursor.value.getSourceAsMap()); // 每个type的mapping
}
}
/**
*
* Elasticsearch还有分析聚合这么一个功能，类似与Mysql中的分组函数、统计数据。
* 贴个链接：
*
* http://blog.csdn.net/napoay/article/details/53484730
*/
}
上面的代码是到：http://blog.csdn.net/napoay/article/details/53276758为止的。
在练习Demo的时候出现了几个问题：
使用shiled认证，无法下载maven坐标，只能导入jar包(官方给出的maven坐标也找不着….shield被废弃了)
使用shiled认证之后，上面博主给出的连接ElasticSearch代码有错，抛出了异常。上网找了几篇资料，无法解决我的问题：
http://blog.csdn.net/sd4015700/article/details/50427852
http://blog.csdn.net/lvyuan1234/article/details/78227778
最后在一篇博文中找到了答案：更新连接Elasticsearch的代码
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "elasticsearch")
.put("shield.user", "zhongfucheng:zhongfucheng")
.build();
TransportClient client = TransportClient.builder()
.addPlugin(ShieldPlugin.class)
.settings(settings).build();
client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
六、总结
在我的个人项目中简单用到了Elasticsearch，也遇到了不少的坑，比如：当创建Elasticsearch的Client的时候，一定要加入嗅探这么一个配置：.put("client.transport.sniff", true)，否则Elasticsearch在使用的时候会非常非常卡，简直令人怀疑人生。
当时我是用Elasticsearch做自动补齐的功能的，也就下面这张图片：
Elasticsearch有suggest这么一个自动提示(补齐)的功能，参考博文：
http://blog.csdn.net/gumpeng/article/details/50346631
http://www.tcao.net/article/86.html
http://blog.csdn.net/liyantianmin/article/details/60778273
具体的操作：
在建立Mapping的时候创建自动补齐的这么一个字段，设置以下的Mapping
//自动补全属性--------
.startObject("suggestName")
.field("type", "completion")
.field("analyzer", "standard")
.field("payloads", "true")
.endObject()
//自动补全属性结束--------
当用户加入新的索引记录的时候，自动补齐字段就是我们的关键字段
public static String String2JSON(String... strings) throws IOException {
String suggestName = strings[2];
if (suggestName.length() > 0) {
}
XContentBuilder builder = jsonBuilder()
.startObject()
.field("userId", strings[0])
.field("webSiteAddr", strings[1])
.field("webSiteName", strings[2])
//自动补全字段
.field("suggestName", strings[2])
.endObject();
return builder.string();
}
其他基础的东西其实都是Lucene演变过来的，要是没学过Lucene可以去看看我另外一篇博文：
如果文章有错的地方欢迎指正，大家互相交流。习惯在微信看技术文章，想要获取更多的Java资源的同学，可以关注微信公众号:Java3y