这篇博客介绍一下Elasticsearch对多个文档进行索引的简便方法。Bulk api的支持可以实现一次请求执行批量的添加、删除、更新等操作.Bulk操作使用的是UDP协议，UDP无法确保与ElasticSearch服务器通信时不丢失数据.
一、Bulk API
使用bulk命令时，REST API以_bulk结尾,批量操作写在json文件中，官网给出的语法格式：
action_and_meta_data\n
optional_source\n
action_and_meta_data\n
optional_source\n
....
action_and_meta_data\n
optional_source\n也就是说每一个操作都有2行数据组成，末尾要回车换行。第一行用来说明操作命令和原数据、第二行是自定义的选项.举个例子，同时执行插入2条数据、删除一条数据, 新建bulkdata.json,写入如下内容：
{ "create" : { "_index" : "blog", "_type" : "article", "_id" : "3" }}
{ "title":"title1","posttime":"2016-07-02","content":"内容一" }
{ "create" : { "_index" : "blog", "_type" : "article", "_id" : "4" }}
{ "title":"title2","posttime":"2016-07-03","content":"内容2" }
{ "delete":{"_index" : "blog", "_type" : "article", "_id" : "1" }}执行：
$ curl -XPOST "http://localhost:9200/_bulk?pretty" --data-binary @bulkAdd.json
{
"took" : 11,
"errors" : false,
"items" : [ {
"create" : {
"_index" : "blog",
"_type" : "article",
"_id" : "13",
"_version" : 1,
"_shards" : {
"total" : 1,
"successful" : 1,
"failed" : 0
},
"status" : 201
}
} ]
}注意：行末要回车换行，不然会因为命令不能识别而出现错误.
$ curl -XPOST "http://localhost:9200/_bulk?pretty" --data-binary @bulkAdd.json
{
"error" : {
"root_cause" : [ {
"type" : "action_request_validation_exception",
"reason" : "Validation Failed: 1: no requests added;"
} ],
"type" : "action_request_validation_exception",
"reason" : "Validation Failed: 1: no requests added;"
},
"status" : 400
}二、批量导出
下面的例子是把索引库中的文档以json格式批量导出到文件中，其中集群名称为”bropen”,索引库名为”blog”,type为”article”,项目根目录下新建files/bulk.txt,索引内容写入bulk.txt中:
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.transport.TransportClient;
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.search.SearchHits;
public class ElasticSearchBulkOut {
public static void main(String[] args) {
try {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "bropen").build();// cluster.name在elasticsearch.yml
Client client = TransportClient.builder().settings(settings).build()
.addTransportAddress(new InetSocketTransportAddress(
InetAddress.getByName("127.0.0.1"), 9300));
QueryBuilder qb = QueryBuilders.matchAllQuery();
SearchResponse response = client.prepareSearch("blog")
.setTypes("article").setQuery(QueryBuilders.matchAllQuery())
.execute().actionGet();
SearchHits resultHits = response.getHits();
File article = new File("files/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();
}
}
}
三、批量导入
从刚才导出的bulk.txt文件中按行读取，然后bulk导入。首先通过调用client.prepareBulk()实例化一个BulkRequestBuilder对象,调用BulkRequestBuilder对象的add方法添加数据。实现代码：
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
public class ElasticSearchBulkIn {
public static void main(String[] args) {
try {
Settings settings = Settings.settingsBuilder()
.put("cluster.name", "bropen").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("files/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();
}
}
}
参考文档：
