Activiti从当前任务任意回退至已审批任务

http://www.verydemo.com/demo_c161_i143918.html

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.activiti.engine.ActivitiException;
import org.activiti.engine.RepositoryService;
import org.activiti.engine.impl.ProcessEngineImpl;
import org.activiti.engine.impl.RepositoryServiceImpl;
import org.activiti.engine.impl.db.DbSqlSession;
import org.activiti.engine.impl.db.DbSqlSessionFactory;
import org.activiti.engine.impl.db.ListQueryParameterObject;
import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
import org.activiti.engine.impl.persistence.entity.HistoricTaskInstanceEntity;
import org.activiti.engine.impl.persistence.entity.IdentityLinkEntity;
import org.activiti.engine.impl.persistence.entity.ProcessDefinitionEntity;
import org.activiti.engine.impl.persistence.entity.TaskEntity;
import org.activiti.engine.impl.pvm.process.ActivityImpl;
import org.activiti.rest.api.ActivitiUtil;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

/*
* 2013.01.25
*
* 任务回退
*
* 需求：从当前任务 任意回退至已审批任务
* 方法：通过activiti源代码里的sqlSession直接修改数据库
*
* 第一步 完成历史TASK覆盖当前TASK
* 用hi_taskinst修改当前ru_task
* ru_task.ID_=hi_taskinst.ID_
* ru_task.NAME_=hi_taskinst.NAME_
* ru_task.TASK_DEF_KEY_=hi_taskinst.TASK_DEF_KEY_
*
* 第二步
* 修改当前任务参与人列表
* ru_identitylink 用ru_task.ID_去ru_identitylink 索引
* ru_identitylink.TASK_ID_=hi_taskinst.ID_
* ru_identitylink.USER_ID=hi_taskinst.ASSIGNEE_
*
* 第三步修改流程记录节点 把ru_execution的ACT_ID_ 改为hi_taskinst.TASK_DEF_KEY_
*
* author:pvii007
* version:1.0
*/
public class DbTaskReturn
{
	public static final int I_NO_OPERATION = 0;

	public static final int I_DONE = 1;

	public static final int I_TASK_NOT_FOUND = 2;

	public static final int I_ROLLBACK = 3;

	/*
	* 实现回退方法
	*/
	public static int dbBackTo(String currentTaskId, String backToTaskId)
	{
		int result = DbTaskReturn.I_NO_OPERATION;
		SqlSession sqlSession = getSqlSession();
		TaskEntity currentTaskEntity = getCurrentTaskEntity(currentTaskId);
		HistoricTaskInstanceEntity backToHistoricTaskInstanceEntity = getHistoryTaskEntity(backToTaskId);
		if (currentTaskEntity == null || backToHistoricTaskInstanceEntity == null)
		{
			return DbTaskReturn.I_TASK_NOT_FOUND;
		}
		String processDefinitionId = currentTaskEntity.getProcessDefinitionId();
		String executionId = currentTaskEntity.getExecutionId();
		String currentTaskEntityId = currentTaskEntity.getId();
		String backToHistoricTaskInstanceEntityId = backToHistoricTaskInstanceEntity.getId();
		String backToTaskDefinitionKey = backToHistoricTaskInstanceEntity.getTaskDefinitionKey();
		String backToAssignee = backToHistoricTaskInstanceEntity.getAssignee();
		boolean success = false;
		try
		{
			// 1.
			StepOne_use_hi_taskinst_to_change_ru_task(sqlSession, currentTaskEntity, backToHistoricTaskInstanceEntity);
			// 2.
			StepTwo_change_ru_identitylink(sqlSession, currentTaskEntityId, backToHistoricTaskInstanceEntityId,
				backToAssignee);
			// 3.
			StepThree_change_ru_execution(sqlSession, executionId, processDefinitionId, backToTaskDefinitionKey);
			success = true;
		}
		catch (Exception e)
		{
			throw new ActivitiException("dbBackTo Exception", e);
		}
		finally
		{
			if (success)
			{
				sqlSession.commit();
				result = DbTaskReturn.I_DONE;
			}
			else
			{
				sqlSession.rollback();
				result = DbTaskReturn.I_ROLLBACK;
			}
			sqlSession.close();
		}
		return result;
	}

	private static void StepThree_change_ru_execution(SqlSession sqlSession, String executionId,
			String processDefinitionId, String backToTaskDefinitionKey) throws Exception
	{
		List<ExecutionEntity> currentExecutionEntityList = sqlSession.selectList("selectExecution", executionId);
		if (currentExecutionEntityList.size() > 0)
		{
			ActivityImpl activity = getActivitiImp(processDefinitionId, backToTaskDefinitionKey);
			Iterator<ExecutionEntity> execution = currentExecutionEntityList.iterator();
			while (execution.hasNext())
			{
				ExecutionEntity e = execution.next();
				e.setActivity(activity);
				p(sqlSession.update("updateExecution", e));
			}
		}
	}

	private static void StepTwo_change_ru_identitylink(SqlSession sqlSession, String currentTaskEntityId,
			String backToHistoricTaskInstanceEntityId, String backToAssignee) throws Exception
	{
		ListQueryParameterObject para = new ListQueryParameterObject();
		para.setParameter(currentTaskEntityId);
		List<IdentityLinkEntity> currentTaskIdentityLinkEntityList = sqlSession.selectList("selectIdentityLinksByTask",
			para);
		if (currentTaskIdentityLinkEntityList.size() > 0)
		{
			Iterator<IdentityLinkEntity> identityLinkEntityList = currentTaskIdentityLinkEntityList.iterator();
			IdentityLinkEntity identityLinkEntity;
			TaskEntity tmpTaskEntity;
			tmpTaskEntity = new TaskEntity();
			tmpTaskEntity.setId(backToHistoricTaskInstanceEntityId);
			while (identityLinkEntityList.hasNext())
			{
				identityLinkEntity = identityLinkEntityList.next();
				identityLinkEntity.setTask(tmpTaskEntity);
				identityLinkEntity.setUserId(backToAssignee);
				Map<String, Object> parameters = new HashMap<String, Object>();
				parameters.put("id", identityLinkEntity.getId());
				sqlSession.delete("deleteIdentityLink", parameters);
				sqlSession.insert("insertIdentityLink", identityLinkEntity);
			}
		}
	}

	private static void StepOne_use_hi_taskinst_to_change_ru_task(SqlSession sqlSession, TaskEntity currentTaskEntity,
			HistoricTaskInstanceEntity backToHistoricTaskInstanceEntity) throws Exception
	{
		sqlSession.delete("deleteTask", currentTaskEntity);
		currentTaskEntity.setName(backToHistoricTaskInstanceEntity.getName());
		currentTaskEntity.setTaskDefinitionKey(backToHistoricTaskInstanceEntity.getTaskDefinitionKey());
		currentTaskEntity.setId(backToHistoricTaskInstanceEntity.getId());
		sqlSession.insert("insertTask", currentTaskEntity);
	}

	public static void p(Object o)
	{
		System.out.println(o);
	}

	private static ActivityImpl getActivitiImp(String processDefinitionId, String taskDefinitionKey)
	{
		RepositoryService repositoryService = ActivitiUtil.getRepositoryService();
		ProcessDefinitionEntity processDefinition = (ProcessDefinitionEntity) ((RepositoryServiceImpl) repositoryService)
				.getDeployedProcessDefinition(processDefinitionId);
		List<ActivityImpl> activitiList = processDefinition.getActivities();
		boolean b;
		Object activityId;
		for (ActivityImpl activity : activitiList)
		{
			activityId = activity.getId();
			b = activityId.toString().equals(taskDefinitionKey);
			if (b)
			{
				return activity;
			}
		}
		return null;
	}

	private static TaskEntity getCurrentTaskEntity(String id)
	{
		return (TaskEntity) ActivitiUtil.getTaskService().createTaskQuery().taskId(id).singleResult();
	}

	private static HistoricTaskInstanceEntity getHistoryTaskEntity(String id)
	{
		return (HistoricTaskInstanceEntity) ActivitiUtil.getHistoryService().createHistoricTaskInstanceQuery()
				.taskId(id).singleResult();
	}

	private static SqlSession getSqlSession()
	{
		ProcessEngineImpl processEngine = (ProcessEngineImpl) ActivitiUtil.getProcessEngine();
		DbSqlSessionFactory dbSqlSessionFactory = (DbSqlSessionFactory) processEngine.getProcessEngineConfiguration()
				.getSessionFactories().get(DbSqlSession.class);
		SqlSessionFactory sqlSessionFactory = dbSqlSessionFactory.getSqlSessionFactory();
		return sqlSessionFactory.openSession();
	}
}