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ElasticSearch API for JAVA 学习笔记

Client
Client是一个类,通过这个类可以实现对ES集群的各种操作:Index, Get, Delete , Search,以及对ES集群的管理任务。
Client的构造需要基于TransportClient
TransportClient
TransportClient可以远程连接ES集群,通过一个传输模块,但是它不真正的连接到集群,只是获取集群的一个或多个初始传输地址,在每次请求动作时,才真正连接到ES集群。
Settings
Settings类主要是在启动Client之前,配置一些属性参数,主要配置集群名称cluster.name,还有其他参数:
client.transport.sniff  是否为传输client添加嗅探功能
client.transport.ignore_cluster_name 设为true,忽略连接节点的集群名称验证
client.transport.ping_timeout 设置ping节点时的时间限,默认5s
client.transport.nodes_sampler_interval 设置sample/ping nodes listed 间隔时间,默认5s

//通过Settings类设置属性参数
Settings settings = Settings.settingsBuilder().put("cluster.name","index-name").build();

//启动Client
Client client = TransportClient.builder().settings(settings).build().
addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("192.168.xxx.xxx"),9300));

//如果不需要设置参数,直接如下
/*Client client = TransportClient.builder().build().
addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("192.168.xxx.xxx"),9300));*/

//关闭Clinet
client.close();
Document API
主要分为以下类:Index API , Get API , Delete API , Update API, Multi Get API, Bulk API
es中的增删改查
Index API可以索引一个典型的JSON文档到指定的索引中,并且可以使它可以检索。
产生JSON
JSON产生可以有以下几种方式:
手动拼接一个JSON字符串
使用Map
使用第三方库,比如Jackson
使用内置的XContentFactory.jsonBuilder()
每种类型都会转换为byte[],因此如果对象已经是这种形式,可以直接使用,jsonBuilder是一个高度优化了的JSON产生器,它直接构造byte[]
通过下边的代码讲解四种方法:index-api, get-api, delete-api, update-api
/**
* es-api的方法学习:
* 1.prepareIndex方法:索引数据到ElasticSearch
* 2.prepareGet方法:获取信息
* 3.prepareDelete方法:删除信息
* 4.update方法:更新信息
* 4.1 upsert:在使用update方法时:
* a:针对文档不存在的情况时,做出index数据的操作,update无效;
* b:如果文档存在,那么index数据操作无效,update有效;
*/
public static void main(String[] args) throws IOException, InterruptedException, ExecutionException {
//通过Settings类设置属性参数
Settings settings = Settings.settingsBuilder().put("cluster.name","myApp").build();

//启动Client
Client client = null;
try {
client = TransportClient.builder().settings(settings).build().
addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("101.200.124.27"),9300));
} catch (UnknownHostException e) {
e.printStackTrace();
}
//执行操作
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
XContentBuilder jsonBuilder = XContentFactory.jsonBuilder()
.startObject()
.field("user","yuchen")
.field("interest","reading book")
.field("insert_time",df.format(new Date()))
.endObject();
//1.prepareIndex方法:索引数据到ElasticSearch
IndexResponse response = client.prepareIndex("index-test","weibo","4")
.setSource(jsonBuilder)
.get();

String _index = response.getIndex();
String _type = response.getType();
String _id = response.getId();
long _version = response.getVersion();
boolean created = response.isCreated();
System.out.println(_index+" "+_type+" "+_id+" "+_version+" "+created);

//2.prepareGet方法:获取信息
GetResponse getResponse = client.prepareGet("index-test","weibo","1").get();
System.out.println(getResponse.getSourceAsString());

//3.prepareDelete方法:删除信息
DeleteResponse deleteResponse = client.prepareDelete("index-test","weibo","4").get();
System.out.println(deleteResponse.isFound());

//4.update方法:更新信息
UpdateRequest updateRequest = new UpdateRequest();
updateRequest.index("index-test");
updateRequest.type("weibo");
updateRequest.id("1");
updateRequest.doc(XContentFactory.jsonBuilder().startObject().field("interest","music").endObject());
UpdateResponse updateResponse = client.update(updateRequest).get();
System.out.println(updateResponse.isCreated());
//update方法: 可以为已有的文档添加新的字段
UpdateResponse updateResponse2 = client.prepareUpdate("index-test", "weibo", "1")
.setDoc(XContentFactory.jsonBuilder()
.startObject()
.field("interest2","reading")
.endObject()).get();
System.out.println(updateResponse2.isCreated());
//4.1 upsert:在使用update方法时,a:针对文档不存在的情况时,做出index数据的操作,update无效;
// b:如果文档存在,那么index数据操作无效,update有效;
//先构建一个IndexRequest
IndexRequest indexRequest = new IndexRequest("index-test","weibo","14");
indexRequest.source(XContentFactory.jsonBuilder()
.startObject()
.field("user","yuchen2")
.field("interest","eating")
.field("insert_time",df.format(new Date()))
.endObject());
//再构建一个UpdateRequest,并用IndexRequest关联
UpdateRequest updateRequest3 = new UpdateRequest("index-test","weibo","14");
updateRequest3.doc(XContentFactory.jsonBuilder()
.startObject()
.field("interest2","love")
.endObject()
).upsert(indexRequest);
client.update(updateRequest3).get();

if(client != null){
client.close();
}
}
批量操作
Multi Get Api 和 Bulk Api可进行批量的增删改查
使用Multi Get Api 批量获取:
//1. Muti-get Api
//可以指定单个id,也在index,type下指定一个id-list;也可以指定别的index/type
MultiGetResponse multiGetResponse = client.prepareMultiGet()
.add("index-test","weibo","1")//指定单个id
.add("index-test","weibo","11","13","14")//指定一个id-list
.add("index-other","news","1","3").get();//指定别的index/type
for(MultiGetItemResponse item:multiGetResponse){
GetResponse response = item.getResponse();
System.out.println(response.getSourceAsString());
}
Bulk Api批量增加:
//2.Bulk Api:可以进行批量index和批量删除操作
//2.1批量增加
BulkRequestBuilder bulkRequest = client.prepareBulk();
bulkRequest.add(client.prepareIndex("index-test", "weibo", "20")
.setSource(XContentFactory.jsonBuilder()
.startObject()
.field("user", "yuchen20")
.field("postDate", new Date())
.field("message", "trying out Elasticsearch")
.endObject()
)
);
bulkRequest.add(client.prepareIndex("index-test", "weibo", "21")
.setSource(XContentFactory.jsonBuilder()
.startObject()
.field("user", "yuchen21")
.field("postDate", new Date())
.field("message", "trying out Elasticsearch")
.endObject()
)
);

BulkResponse bulkResponse = bulkRequest.get();
if(bulkResponse.hasFailures()){
//...
}
Bulk Api批量删除:
//2.2批量删除
BulkRequestBuilder bulkRequest = client.prepareBulk();
bulkRequest.add(client.prepareDelete("index-test", "weibo", "20")
);
bulkRequest.add(client.prepareDelete("index-test", "weibo", "21")
);

BulkResponse bulkResponse = bulkRequest.get();
if(bulkResponse.hasFailures()){
System.out.println("bulk error:"+bulkResponse.buildFailureMessage());
}
Bulk Api 批量更新
//2.3批量更新
BulkRequestBuilder bulkRequest = client.prepareBulk();
bulkRequest.add(client.prepareUpdate("index-test", "weibo", "11").setDoc(XContentFactory
.jsonBuilder().startObject()
.field("country","China")//新添加字段
.endObject()
)
);
bulkRequest.add(client.prepareUpdate("index-test", "weibo", "13").setDoc(XContentFactory
.jsonBuilder().startObject()
.field("user","yuchen13")//更新字段
.endObject()
)
);

BulkResponse bulkResponse = bulkRequest.get();
if(bulkResponse.hasFailures()){
System.out.println("bulk error:"+bulkResponse.buildFailureMessage());
}
BulkProcessor设置批量请求的属性
//BulkProcessor
BulkProcessor bulkProcessor = BulkProcessor.builder(client, new BulkProcessor.Listener() {
@Override
public void beforeBulk(long arg0, BulkRequest arg1) {
//批量执行前做的事情
System.out.println("bulk api action starting...");
}
@Override
public void afterBulk(long arg0, BulkRequest arg1, Throwable arg2) {
System.out.println("exception:bukl api action ending...:"+arg2.getMessage());
}
@Override
public void afterBulk(long arg0, BulkRequest arg1, BulkResponse arg2) {
//正常执行完毕后...
System.out.println("normal:bukl api action ending...");
}
})
//设置多种条件,对批量操作进行限制,达到限制中的任何一种触发请求的批量提交
.setBulkActions(1000)//设置批量操作一次性执行的action个数,根据请求个数批量提交
//.setBulkSize(new ByteSizeValue(1,ByteSizeUnit.KB))//设置批量提交请求的大小允许的最大值
//.setFlushInterval(TimeValue.timeValueMillis(100))//根据时间周期批量提交请求
//.setConcurrentRequests(1)//设置允许并发请求的数量
//设置请求失败时的补偿措施,重复请求3次
//.setBackoffPolicy(BackoffPolicy.exponentialBackoff(TimeValue.timeValueMillis(100), 3))
.build();
for(int i =0;i<100000;i++){
bulkProcessor.add(new IndexRequest("index-test","weibo2",""+i).source(
XContentFactory
.jsonBuilder()
.startObject()
.field("name","yuchen"+i)
.field("interest","love"+i)
.endObject()));
}
bulkProcessor.awaitClose(5, TimeUnit.MINUTES);//释放bulkProcessor资源
System.out.println("load succeed!");

默认的参数:
sets bulkActions to 1000
sets bulkSize to 5mb
does not set flushInterval
sets concurrentRequests to 1
sets backoffPolicy to an exponential backoff with 8 retries and a start delay of 50ms. The total wait time is roughly 5.1 seconds.

 

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