couchbase

Couchbase是一个开源的NoSQL文档数据库。 它允许访问，索引和查询JSON文档，同时利用集成的分布式缓存来实现高性能数据访问。

开发人员可以使用不同的语言（Java，Go，.NET，Node，PHP，Python，C） 多种SDK将应用程序编写到Couchbase。 该博客将展示如何使用Java SDK for Couchbase轻松创建CRUD应用程序。

带有Couchbase的REST

该应用程序将使用curl向部署在WildFly上的JAX-RS端点发出REST命令。 然后，这些命令将对Couchbase中的travel-sample存储桶执行CRUD操作。 N1QL（JSONSQL查询语言）将用于与Couchbase通信以检索结果。 “生成器模式”和原始N1QL命令都将使用。

TL; DR

样本的完整源代码和说明可在github.com/arun-gupta/couchbase-javaee中找到 。

让我们开始吧！

运行Couchbase服务器

可以从“ Couchbase服务器下载”页面轻松下载Couchbase服务器 。 在容器化的世界中， 使用Docker启动Couchbase服务器要容易得多 。

如果在您的计算机上配置了Docker，那么最简单的方法是将Docker Compose用于Couchbase ：

mycouchbase:name: mycouchbaseimage: couchbase/servervolumes:- ~/couchbase:/opt/couchbase/varports:- 8091:8091- 8092:8092 - 8093:8093 - 11210:11210

启动应用程序服务器显示：

> docker-compose up -d
Creating couchbaseserver_mycouchbase_1

然后日志可以看成是：

> docker-compose logs
Attaching to couchbaseserver_mycouchbase_1
mycouchbase_1 | Starting Couchbase Server -- Web UI available at http://<ip>:8091

该数据库需要配置，并在“ 配置Couchbase服务器”中进行了说明 。 确保安装travel-sample桶。

在WildFly上部署Java EE应用程序

• 下载WildFly 9.0.2 ，解压缩，然后以./wildfly-9.0.0.Final/bin/standalone.sh启动WildFly应用程序服务器。
• Git克隆仓库： git clone https://github.com/arun-gupta/couchbase-javaee.git
• 更改目录cd couchbase-javaee
• 将应用程序部署到WildFly： mvn install -Pwildfly 。

该应用程序通过导入以下Maven坐标将Java SDK用于Couchbase ：

<dependency><groupId>com.couchbase.client</groupId><artifactId>java-client</artifactId><version>2.2.1</version>
</dependency>

使用cURL调用REST端点

GET航空公司资源（最多10个）

让我们查询数据库以列出10个航空公司资源。

请求

~ > curl -v http://localhost:8080/couchbase-javaee/resources/airline
* Hostname was NOT found in DNS cache
*   Trying ::1...
* connect to ::1 port 8080 failed: Connection refused
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /couchbase-javaee/resources/airline HTTP/1.1
> User-Agent: curl/7.37.1
> Host: localhost:8080
> Accept: */*
>

响应

< HTTP/1.1 200 OK
< Connection: keep-alive
< X-Powered-By: Undertow/1
* Server WildFly/9 is not blacklisted
< Server: WildFly/9
< Content-Type: application/octet-stream
< Content-Length: 1415
< Date: Wed, 18 Nov 2015 21:19:15 GMT
<
* Connection #0 to host localhost left intact
[{"travel-sample":{"country":"France","iata":"SB","callsign":"AIRCALIN","name":"Air Caledonie International","icao":"ACI","id":139,"type":"airline"}}, {"travel-sample":{"country":"United States","iata":"WQ","callsign":null,"name":"PanAm World Airways","icao":"PQW","id":13633,"type":"airline"}}, {"travel-sample":{"country":"United Kingdom","iata":"BA","callsign":"SPEEDBIRD","name":"British Airways","icao":"BAW","id":1355,"type":"airline"}}, {"travel-sample":{"country":"United States","iata":"FL","callsign":"CITRUS","name":"AirTran Airways","icao":"TRS","id":1316,"type":"airline"}}, {"travel-sample":{"country":"United States","iata":"-+","callsign":null,"name":"U.S. Air","icao":"--+","id":13391,"type":"airline"}}, {"travel-sample":{"country":"United States","iata":"Q5","callsign":"MILE-AIR","name":"40-Mile Air","icao":"MLA","id":10,"type":"airline"}}, {"travel-sample":{"country":"France","iata":"AF","callsign":"AIRFRANS","name":"Air France","icao":"AFR","id":137,"type":"airline"}}, {"travel-sample":{"country":"United States","iata":"K5","callsign":"SASQUATCH","name":"SeaPort Airlines","icao":"SQH","id":10765,"type":"airline"}}, {"travel-sample":{"country":"France","iata":"A5","callsign":"AIRLINAIR","name":"Airlinair","icao":"RLA","id":1203,"type":"airline"}}, {"travel-sample":{"country":"United Kingdom","iata":"5W","callsign":"FLYSTAR","name":"Astraeus","icao":"AEU","id":112,"type":"airline"}}]

N1QL查询对此写为：

N1qlQuery query = N1qlQuery.simple(select("*").from(i(database.getBucket().name())).limit(10));

并且也可以写成：

SELECT * FROM `travel-sample` LIMIT 10

您可以选择更新代码以包含ORDER BY子句，如N1QL教程中所示。

获得一份航空公司资源

使用id属性查询单个航空公司资源

请求

~ > curl -v http://localhost:8080/couchbase-javaee/resources/airline/139
* Hostname was NOT found in DNS cache
*   Trying ::1...
* connect to ::1 port 8080 failed: Connection refused
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /couchbase-javaee/resources/airline/139 HTTP/1.1
> User-Agent: curl/7.37.1
> Host: localhost:8080
> Accept: */*
>

响应

< HTTP/1.1 200 OK
< Connection: keep-alive
< X-Powered-By: Undertow/1
* Server WildFly/9 is not blacklisted
< Server: WildFly/9
< Content-Type: application/octet-stream
< Content-Length: 148
< Date: Wed, 18 Nov 2015 21:23:34 GMT
<
* Connection #0 to host localhost left intact
{"travel-sample":{"country":"France","iata":"SB","callsign":"AIRCALIN","name":"Air Caledonie International","icao":"ACI","id":139,"type":"airline"}}

发布新的航空公司资源

了解如何使用CBQ工具从CLI运行N1QL查询并验证现有样本数据：

bin > ./cbq -engine=http://192.168.99.100:8093
Couchbase query shell connected to http://192.168.99.100:8093/ . Type Ctrl-D to exit.
cbq> select * from `travel-sample` where name="Airlinair" limit 10;
{"requestID": "ce2de67b-2c05-47df-afbe-343cb7409d2b","signature": {"*": "*"},"results": [{"travel-sample": {"callsign": "AIRLINAIR","country": "France","iata": "A5","icao": "RLA","id": 1203,"name": "Airlinair","type": "airline"}}],"status": "success","metrics": {"elapsedTime": "3.418285894s","executionTime": "3.418232688s","resultCount": 1,"resultSize": 294}
}

该查询检索航空公司名称为Airlinair文档。 该计数显示在metrics.resultCount 。

使用POST创建一个新文档。

请求

~ > curl -v -H "Content-Type: application/json" -X POST -d '{"country":"France","iata":"A5","callsign":"AIRLINAIR","name":"Airlinair","icao":"RLA","type":"airline"}' http://localhost:8080/couchbase-javaee/resources/airline
* Hostname was NOT found in DNS cache
*   Trying ::1...
* connect to ::1 port 8080 failed: Connection refused
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> POST /couchbase-javaee/resources/airline HTTP/1.1
> User-Agent: curl/7.37.1
> Host: localhost:8080
> Accept: */*
> Content-Type: application/json
> Content-Length: 104
>

响应

* upload completely sent off: 104 out of 104 bytes
< HTTP/1.1 200 OK
< Connection: keep-alive
< X-Powered-By: Undertow/1
* Server WildFly/9 is not blacklisted
< Server: WildFly/9
< Content-Type: application/octet-stream
< Content-Length: 117
< Date: Wed, 18 Nov 2015 21:42:51 GMT
<
* Connection #0 to host localhost left intact
{"country":"France","iata":"A5","callsign":"AIRLINAIR","name":"Airlinair","icao":"RLA","id":"19810","type":"airline"}

使用CBQ再次查询，现在结果显示为：

cbq> select * from `travel-sample` where name="Airlinair" limit 10;
{"requestID": "5e79031a-f7ee-4cc9-8c87-4e3b7484f09f","signature": {"*": "*"},"results": [{"travel-sample": {"callsign": "AIRLINAIR","country": "France","iata": "A5","icao": "RLA","id": 1203,"name": "Airlinair","type": "airline"}},{"travel-sample": {"callsign": "AIRLINAIR","country": "France","iata": "A5","icao": "RLA","id": "19810","name": "Airlinair","type": "airline"}}],"status": "success","metrics": {"elapsedTime": "3.342391947s","executionTime": "3.342343455s","resultCount": 2,"resultSize": 591}
}

请注意，返回的是两个JSON文档，而不是发出POST命令之前的一个。

放置现有的航空公司资源

使用HTTP POST更新现有资源。

travel-sample存储区的数据模型需要在有效负载和URI中都包含“ id”属性。

请求

~ > curl -v -H "Content-Type: application/json" -X PUT -d '{"country":"France","iata":"A5","callsign":"AIRLINAIR","name":"Airlin Air","icao":"RLA","type":"airline","id": "19810"}' http://localhost:8080/couchbase-javaee/resources/airline/19810
* Hostname was NOT found in DNS cache
*   Trying ::1...
* connect to ::1 port 8080 failed: Connection refused
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> PUT /couchbase-javaee/resources/airline/19810 HTTP/1.1
> User-Agent: curl/7.37.1
> Host: localhost:8080
> Accept: */*
> Content-Type: application/json
> Content-Length: 118
>
* upload completely sent off: 118 out of 118 bytes

航空公司名称从“ Airlinair”更新为“ Airlin Air”，所有其他属性保持不变。

响应

< HTTP/1.1 200 OK
< Connection: keep-alive
< X-Powered-By: Undertow/1
* Server WildFly/9 is not blacklisted
< Server: WildFly/9
< Content-Type: application/octet-stream
< Content-Length: 117
< Date: Wed, 18 Nov 2015 21:46:16 GMT
<
* Connection #0 to host localhost left intact
{"country":"France","iata":"A5","callsign":"AIRLINAIR","name":"Airlin Air","icao":"RLA","id":"19810","type":"airline"}

更新的记录显示在响应中。

查询Airlinair会给出：

cbq> select * from `travel-sample` where name="Airlinair" limit 10;
{"requestID": "a8d72427-9f4b-49ab-a77a-17cd99cdce5f","signature": {"*": "*"},"results": [{"travel-sample": {"callsign": "AIRLINAIR","country": "France","iata": "A5","icao": "RLA","id": 1203,"name": "Airlinair","type": "airline"}}],"status": "success","metrics": {"elapsedTime": "3.372603693s","executionTime": "3.37256091s","resultCount": 1,"resultSize": 294}
}

因此，以前添加的记录现在已更新，因此不会出现在查询结果中。 查询Airlin Air可得到：

cbq> select * from `travel-sample` where name="Airlin Air" limit 10;
{"requestID": "a3797a73-d879-4ca1-be90-e07179aae118","signature": {"*": "*"},"results": [{"travel-sample": {"callsign": "AIRLINAIR","country": "France","iata": "A5","icao": "RLA","id": "19810","name": "Airlin Air","type": "airline"}}],"status": "success","metrics": {"elapsedTime": "3.393649025s","executionTime": "3.393530368s","resultCount": 1,"resultSize": 298}
}

这显示了新更新的文档。

删除现有的航空公司资源

查询唯一的ID：

cbq> select * from `travel-sample` where id="19810" limit 10;
{"requestID": "47a315cd-afe4-45a8-8814-5ab3034e0d0f","signature": {"*": "*"},"results": [{"travel-sample": {"callsign": "AIRLINAIR","country": "France","iata": "A5","icao": "RLA","id": "19810","name": "Airlin Air","type": "airline"}}],"status": "success","metrics": {"elapsedTime": "3.006863656s","executionTime": "3.006821997s","resultCount": 1,"resultSize": 298}
}

请注意，返回了一个文档。

让我们删除此文档。

请求

~ > curl -v -X DELETE http://localhost:8080/couchbase-javaee/resources/airline/19810
* Hostname was NOT found in DNS cache
*   Trying ::1...
* connect to ::1 port 8080 failed: Connection refused
*   Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 8080 (#0)
> DELETE /couchbase-javaee/resources/airline/19810 HTTP/1.1
> User-Agent: curl/7.37.1
> Host: localhost:8080
> Accept: */*
>

响应

> HTTP/1.1 200 OK
> Connection: keep-alive
> X-Powered-By: Undertow/1
* Server WildFly/9 is not blacklisted
> Server: WildFly/9
> Content-Type: application/octet-stream
> Content-Length: 136
> Date: Wed, 18 Nov 2015 21:52:47 GMT
>
* Connection #0 to host localhost left intact
{"travel-sample":{"country":"France","iata":"A5","callsign":"AIRLINAIR","name":"Airlin Air","icao":"RLA","id":"19810","type":"airline"}}

删除的文档显示在响应中。

再次查询已删除的ID：

cbq> select * from `travel-sample` where id="19810" limit 10;
{"requestID": "972b0bbd-ba25-4f6c-a30e-ed188bf43588","signature": {"*": "*"},"results": [],"status": "success","metrics": {"elapsedTime": "3.261481199s","executionTime": "3.261431917s","resultCount": 0,"resultSize": 0}
}

而且没有结果返回！

• 如前所述，完整的代码库位于github.com/arun-gupta/couchbase-javaee 。

请享用！

翻译自: https://www.javacodegeeks.com/2015/11/crud-java-application-couchbase-java-ee-wildfly.html

couchbase