web后端是做什么的/北京网站优化方式

既然是开发篇，主要以代码为主，辅助一些说明。所有的内容都是代码实际应该验证过的。

引入的头文件：

import static org.elasticsearch.node.NodeBuilder.nodeBuilder;import java.io.IOException;
import java.net.InetAddress;
import java.util.Date;
import java.util.Map;
import java.util.Set;import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequestBuilder;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.ClusterAdminClient;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.cluster.health.ClusterIndexHealth;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.node.Node;
import static org.elasticsearch.common.xcontent.XContentFactory.*;

创建索引

XContentBuilder mapping = XContentFactory.jsonBuilder().startObject().startObject("settings").field("number_of_shards", 1)//设置分片数量.field("number_of_replicas", 0)//设置副本数量.endObject().endObject().startObject().startObject(type)//type名称.startObject("properties") //下面是设置文档列属性。.startObject("type").field("type", "string").field("store", "yes").endObject().startObject("eventCount").field("type", "long").field("store", "yes").endObject().startObject("eventDate").field("type", "date").field("format", "dateOptionalTime").field("store", "yes").endObject().startObject("message").field("type", "string").field("index", "not_analyzed").field("store", "yes").endObject().endObject().endObject().endObject();CreateIndexRequestBuilder cirb = client.admin().indices().prepareCreate(indexName)//index名称.setSource(mapping);CreateIndexResponse response = cirb.execute().actionGet();
if (response.isAcknowledged()) {System.out.println("Index created.");
} else {System.err.println("Index creation failed.");
}

增加文档

IndexResponse response = client.prepareIndex(indexName, type, "1").setSource(//这里可以直接用json字符串jsonBuilder().startObject().field("type", "syslog").field("eventCount", 1).field("eventDate", new Date()).field("message", "secilog insert doc test").endObject()).get();
System.out.println("index:"+response.getIndex()+" insert doc id:"+response.getId()+" result:"+response.isCreated());

查询文档

GetResponse response = client.prepareGet("secilog", "log", "1").get();
String source = response.getSource().toString();
long version = response.getVersion();
String indexName = response.getIndex();
String type = response.getType();
String id = response.getId();

修改文档

修改文档有两种方式，一种是直接修改，另一种是如果文档不存在则插入存在则修改。

第一种代码

UpdateRequest updateRequest = new UpdateRequest();
updateRequest.index(indexName);
updateRequest.type(type);
updateRequest.id("1");
updateRequest.doc(jsonBuilder().startObject().field("type", "file").endObject());
client.update(updateRequest).get();

第二种代码：

IndexRequest indexRequest = new IndexRequest(indexName, type, "3")
.source(jsonBuilder().startObject().field("type", "syslog").field("eventCount", 2).field("eventDate", new Date()).field("message", "secilog insert doc test").endObject());
UpdateRequest updateRequest = new UpdateRequest(indexName, type, "3").doc(jsonBuilder().startObject().field("type", "file").endObject()).upsert(indexRequest);              
client.update(updateRequest).get();

删除文档

DeleteResponse dresponse = client.prepareDelete("secilog", "log", "4").get();
boolean isFound = dresponse.isFound(); //文档存在返回true,不存在返回false；

删除索引

DeleteIndexRequest delete = new DeleteIndexRequest("secilog");
client.admin().indices().delete(delete);