建立及使用解除安裝工作 creating-and-consuming-jobs-for-offloading

Apache Sling Discovery功能提供Java API,可讓您建立使用JobManager作業和JobConsumer服務。

如需有關建立解除安裝拓撲和設定主題沖銷的資訊,請參閱 正在解除安裝工作.

處理工作承載 handling-job-payloads

解除安裝架構會定義兩個用於識別工作裝載的工作屬性。 解除安裝復寫代理程式會使用這些特性來識別要復寫到拓撲中執行個體的資源:

  • offloading.job.input.payload:以逗號分隔的內容路徑清單。 內容會復寫到執行工作的執行處理。
  • offloading.job.output.payload:以逗號分隔的內容路徑清單。 當作業執行完成時,會將作業裝載復寫到建立作業的執行處理上的這些路徑。

使用 OffloadingJobProperties 列舉以參照屬性名稱:

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

作業不需要裝載。 不過,如果工作需要操作資源,而且工作已解除安裝至未建立工作的電腦,則必須裝載負載。

建立解除安裝工作 creating-jobs-for-offloading

建立呼叫JobManager.addJob方法的使用者端,以建立自動選取的JobConsumer所執行的工作。 提供下列資訊以建立工作:

  • 主題:工作主題。
  • 名稱: (選擇性)
  • 屬性對應: A Map<String, Object> 包含任何數量屬性的物件,例如輸入裝載路徑和輸出裝載路徑。 執行工作的JobConsumer物件可以使用這個Map物件。

以下範例服務會為給定主題和輸入裝載路徑建立作業。

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();
 }
}

為呼叫JobGeneratorImpl.createJob時,記錄會包含以下訊息 com/adobe/example/offloading 主題與 /content/geometrixx/de/services 裝載:

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

開發工作消費者 developing-a-job-consumer

若要使用工作,請開發實作的OSGi服務 org.apache.sling.event.jobs.consumer.JobConsumer 介面。 使用以要使用的主題來識別 JobConsumer.PROPERTY_TOPICS 屬性。

以下範例JobConsumer實作會註冊 com/adobe/example/offloading 主題。 取用者只會將裝載內容節點的Consumed屬性設定為true。

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類別會針對/content/geometrixx/de/services的輸入裝載產生下列記錄訊息:

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

可以使用CRXDE Lite來觀察Consumed屬性:

chlimage_1-25

Maven相依性 maven-dependencies

將下列相依性定義新增至您的pom.xml檔案,讓Maven可以解析解除安裝相關類別。

<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>

前面的範例還需要下列相依性定義:

<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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