为卸载创建和使用作业

Apache Sling Discovery功能提供了一个Java API,允许您创建使用JobManager作业和JobConsumer服务的Java API。

有关创建卸载拓扑并配置主题使用情况的信息,请参阅卸载作业

处理作业负载

卸载框架定义了两个用于标识作业负载的作业属性。 卸载的复制代理使用这些属性来标识要复制到拓扑中实例的资源:

  • offloading.job.input.payload:以逗号分隔的内容路径列表。内容会复制到执行该作业的实例。
  • offloading.job.output.payload:以逗号分隔的内容路径列表。作业执行完成后,作业有效负载将复制到创建作业的实例上的这些路径。

使用OffloadingJobProperties枚举引用属性名称:

  • OffloadingJobProperties.INPUT_PAYLOAD.propertyName()
  • OffloadingJobProperties.OUTPUT_PAYLOAD.propetyName()

作业不需要负载。 但是,如果作业需要处理资源并且作业卸载到未创建作业的计算机,则有效负载是必需的。

为卸载创建作业

创建调用JobManager.addJob方法的客户端,以创建由自动选择的JobConsumer执行的作业。 提供以下信息以创建作业:

  • 主题:作业主题。
  • 名称:(可选)
  • 属性映射:Map<String, Object>对象,其中包含任意数量的属性,如输入有效负载路径和输出有效负载路径。 此映射对象可用于执行该作业的JobConsumer对象。

以下示例服务为给定主题和输入有效负载路径创建作业。

package com.adobe.example.offloading;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Service;
import org.apache.felix.scr.annotations.Reference;

import java.util.HashMap;

import org.apache.sling.event.jobs.Job;
import org.apache.sling.event.jobs.JobManager;

import org.apache.sling.api.resource.ResourceResolverFactory;
import org.apache.sling.api.resource.ResourceResolver;

import com.adobe.granite.offloading.api.OffloadingJobProperties;

@Component
@Service
public class JobGeneratorImpl implements JobGenerator  {

 @Reference
 private JobManager jobManager;
 @Reference ResourceResolverFactory resolverFactory;

 public String createJob(String topic, String payload) throws Exception {
  Job offloadingJob;

  ResourceResolver resolver = resolverFactory.getResourceResolver(null);
  if(resolver.getResource(payload)!=null){

   HashMap<String, Object> jobprops = new HashMap<String, Object>();
   jobprops.put(OffloadingJobProperties.INPUT_PAYLOAD.propertyName(), payload);

   offloadingJob = jobManager.addJob(topic, null, jobprops);
  } else {
   throw new Exception("Payload for job cannot be found");
  }
  if (offloadingJob == null){
   throw new Exception ("Offloading job could not be created");
  }
  return offloadingJob.getId();
 }
}

当为com/adobe/example/offloading主题和/content/geometrixx/de/services负载调用JobGeneratorImpl.createJob时,日志包含以下消息:

10.06.2013 15:43:33.868 *INFO* [JobHandler: /etc/workflow/instances/2013-06-10/model_1554418768647484:/content/geometrixx/en/company] com.adobe.example.offloading.JobGeneratorImpl Received request to make job for topic com/adobe/example/offloading and payload /content/geometrixx/de/services

开发工作客户

要使用作业,请开发一个实现org.apache.sling.event.jobs.consumer.JobConsumer接口的OSGi服务。 使用JobConsumer.PROPERTY_TOPICS属性识别要使用的主题。

以下示例JobConsumer实现在com/adobe/example/offloading主题中进行注册。 用户只需将有效负载内容节点的Unsed属性设置为true即可。

package com.adobe.example.offloading;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.resource.ResourceResolverFactory;
import org.apache.sling.event.jobs.Job;
import org.apache.sling.event.jobs.JobManager;
import org.apache.sling.event.jobs.consumer.JobConsumer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.jcr.Session;
import javax.jcr.Node;

import com.adobe.granite.offloading.api.OffloadingJobProperties;

@Component
@Service
public class MyJobConsumer implements JobConsumer {

 public static final String TOPIC = "com/adobe/example/offloading";

 @Property(value = TOPIC)
 static final String myTopic = JobConsumer.PROPERTY_TOPICS; 

 @Reference
 private ResourceResolverFactory resolverFactory;

 @Reference
 private JobManager jobManager;

 private final Logger log = LoggerFactory.getLogger(getClass());

 public JobResult process(Job job) {
  JobResult result = JobResult.FAILED;
  String topic = job.getTopic();
  log.info("Consuming job of topic: {}", topic);
  String payloadIn =  (String) job.getProperty(OffloadingJobProperties.INPUT_PAYLOAD.propertyName());
  String payloadOut =  (String) job.getProperty(OffloadingJobProperties.OUTPUT_PAYLOAD.propertyName());

  log.info("Job has Input Payload {} and Output Payload {}",payloadIn, payloadOut);

  ResourceResolver resolver = null;
  try {
   resolver = resolverFactory.getAdministrativeResourceResolver(null);
   Session session = resolver.adaptTo(Session.class);
   Node inNode = session.getNode(payloadIn);
   inNode.getNode(Node.JCR_CONTENT).setProperty("consumed",true);
   result = JobResult.OK;
  }catch (Exception e){
   log.info("ERROR -- JOB RESULT IS FAILURE " + e.getMessage());
   result = JobResult.FAILED;
  }
  log.info("Job OK for payload {}",payloadIn);
  return result;
 }
}

MyJobConsumer类为/content/geometrixx/de/services的输入负载生成以下日志消息:

10.06.2013 16:02:40.803 *INFO* [pool-7-thread-17-<main queue>(com/adobe/example/offloading)] com.adobe.example.offloading.MyJobConsumer Consuming job of topic: com/adobe/example/offloading
10.06.2013 16:02:40.803 *INFO* [pool-7-thread-17-<main queue>(com/adobe/example/offloading)] com.adobe.example.offloading.MyJobConsumer Job has Input Payload /content/geometrixx/de/services and Output Payload /content/geometrixx/de/services
10.06.2013 16:02:40.884 *INFO* [pool-7-thread-17-<main queue>(com/adobe/example/offloading)] com.adobe.example.offloading.MyJobConsumer Job OK for payload /content/geometrixx/de/services

使用CRXDE Lite可以观察使用的属性:

chlimage_1-25

Maven依赖项

将以下依赖关系维护添加到pom.xml文件,以便Maven能够解析与卸载相关的类。

<dependency>
   <groupId>org.apache.sling</groupId>
   <artifactId>org.apache.sling.event</artifactId>
   <version>3.1.5-R1485539</version>
   <scope>provided</scope> 
</dependency>
<dependency>
   <groupId>com.adobe.granite</groupId>
   <artifactId>com.adobe.granite.offloading.core</artifactId>
   <version>1.0.4</version>
   <scope>provided</scope>
</dependency>

以前的示例还需要以下依赖关系定义:

<dependency>
   <groupId>org.apache.sling</groupId>
   <artifactId>org.apache.sling.api</artifactId>
   <version>2.4.3-R1488084</version>
   <scope>provided</scope>
</dependency>

<dependency>
   <groupId>org.apache.sling</groupId>
   <artifactId>org.apache.sling.jcr.jcr-wrapper</artifactId>
   <version>2.0.0</version>
   <scope>provided</scope>
</dependency>

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