activiti 流程部署

1. activiti流程部署调用RepositoryService.createDeployment().deploy()。

RepositoryService.createDeployment()返回DeploymentBuilder对象，DeploymentBuilder是部署管理接口。

DeploymentBuilder.deploy()是部署接口，返回Deployment，Deployment里面包含部署ID、名字、部署时间。DeploymentBuilder部分代码如下所示：

  public interface DeploymentBuilder {
    /**
     * Deploys all provided sources to the Activiti engine.
     */
    Deployment deploy();

  }

• DeploymentBuilderImpl实现了接口DeploymentBuilder，DeploymentBuilderImpl.deploy()方法调用了RepositoryServiceImpl.deploy()方法。

  public class DeploymentBuilderImpl implements DeploymentBuilder, Serializable {

    protected transient RepositoryServiceImpl repositoryService;  

    public Deployment deploy() {
      return repositoryService.deploy(this);
    }
  }

RepositoryServiceImpl.deploy()通过命令模式调用DeployCmd.execute()，类DeployCmd实现了流程的部署。

  public class RepositoryServiceImpl extends ServiceImpl implements RepositoryService {

    public Deployment deploy(DeploymentBuilderImpl deploymentBuilder) {
      return commandExecutor.execute(new DeployCmd<Deployment>(deploymentBuilder));
    }
  }

commandExecutor.execute调用DeployCmd之前，切入了拦截器LogInterceptor、 SpringTransactionInterceptor、 CommandContextInterceptor。LogInterceptor是日志拦截器，SpringTransactionInterceptor是事务拦截器，CommandContextInterceptor是命令拦截器，只有命令拦截器会调用DeployCmd.execute，完成DeployCmd.execute调用之后，再将事务提交到数据库。

• 类DeployCmd实现Command接口。DeployCmd将部署文件解析成DeploymentEntity对象，存入部署表；然后调用DeploymentManager.deploy()方法对流程定义，资源文件进行部署。DeployCmd的部分代码如下所示：

  public class DeployCmd<T> implements Command<Deployment>, Serializable {

   public Deployment execute(CommandContext commandContext) {
     DeploymentEntity deployment = deploymentBuilder.getDeployment();
   ...  
     // Save the data
     commandContext
       .getDeploymentEntityManager()
       .insertDeployment(deployment);
   ...  
     // Actually deploy
     commandContext
       .getProcessEngineConfiguration()
       .getDeploymentManager()
       .deploy(deployment, deploymentSettings);
   ...
   }
  }

• 类DeploymentManager管理部署接口Deployer，Deployer实现类有BpmnDeployer、RulesDeployer，BpmnDeployer负责BPMN文件的部署，RulesDeployer负责drl规则文件的部署。 DeploymentManager的部分代码如下所示：

    public class DeploymentManager {

     protected DeploymentCache<ProcessDefinitionEntity> processDefinitionCache;
     protected DeploymentCache<Object> knowledgeBaseCache; // Needs to be object to avoid an import to Drools in this core class
     protected List<Deployer> deployers;

     public void deploy(DeploymentEntity deployment, Map<String, Object> deploymentSettings) {
       for (Deployer deployer: deployers) {
         deployer.deploy(deployment, deploymentSettings);
       }
     }
   }

只有业务规则任务(bussinessRuleTask)才会用到drools规则，其它情况都是部署BPMN文件。BpmnDeployer首先调用BpmnParse.execute验证流程元素的合法性，然后解析出流程定义对象ProcessDefinitionEntity、xml文件流、流程png图片，最后将它们存入到数据库中，完成整个流程的部署。流程部署主要的调用顺序如下：

调用顺序