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。或者去我的Elasticsearch学习记录中找。

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
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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！
     */
    @Test
    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
     */
    @Test
    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)
     *
     */
    @Test
    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
     */
    @Test
    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
     */
    @Test
    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
     */

    @Test
    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
     */
    @Test
    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
     */

    @Test
    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：

Lucene就这么简单

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