import org.activiti.engine.ProcessEngine;

import org.activiti.engine.TaskService;

import org.activiti.engine.impl.RepositoryServiceImpl;

import org.activiti.engine.impl.RuntimeServiceImpl;

import org.activiti.engine.impl.interceptor.Command;

import org.activiti.engine.impl.interceptor.CommandContext;

import org.activiti.engine.impl.persistence.entity.ExecutionEntity;

import org.activiti.engine.impl.persistence.entity.ProcessDefinitionEntity;

import org.activiti.engine.impl.persistence.entity.TaskEntity;

import org.activiti.engine.impl.pvm.process.ActivityImpl;

/**

 * Created by Administrator on 2016/11/11.

 */

public class TaskFlowControlService {

    ProcessEngine _processEngine;

    private String _processId;

    public TaskFlowControlService(ProcessEngine processEngine, String processId)

    {

        this._processEngine = processEngine;

        this._processId = processId;

    }

    /**

     *  跳转至指定活动节点

     * @param targetTaskDefinitionKey

     */

    public void jump(String targetTaskDefinitionKey){

        TaskEntity currentTask = (TaskEntity)_processEngine.getTaskService()

                .createTaskQuery()

                .processInstanceId(_processId).singleResult();

        jump(currentTask,targetTaskDefinitionKey);

    }

    /**

     * @param currentTaskEntity 当前任务节点

     * @param targetTaskDefinitionKey  目标任务节点（在模型定义里面的节点名称）

     */

    private void jump(final TaskEntity currentTaskEntity, String targetTaskDefinitionKey){

        final ActivityImpl activity = getActivity(_processEngine,

                currentTaskEntity.getProcessDefinitionId(),targetTaskDefinitionKey);

        final ExecutionEntity execution = (ExecutionEntity)_processEngine.getRuntimeService()

                .createExecutionQuery().executionId(currentTaskEntity.getExecutionId()).singleResult();

        final TaskService taskService = _processEngine.getTaskService();

        ((RuntimeServiceImpl)_processEngine.getRuntimeService()).getCommandExecutor()

                .execute(new Command<java.lang.Void>() {

                    public Void execute(CommandContext commandContext) {

                        //创建新任务

                        execution.setActivity(activity);

                        execution.executeActivity(activity);

                        //删除当前的任务

                        //不能删除当前正在执行的任务，所以要先清除掉关联

                        currentTaskEntity.setExecutionId(null);

                        taskService.saveTask(currentTaskEntity);

                        taskService.deleteTask(currentTaskEntity.getId(),true);

                        return null;

                    }

                });

    }

    private ActivityImpl getActivity(ProcessEngine processEngine, String processDefId, String activityId)

    {

        ProcessDefinitionEntity pde = getProcessDefinition(processEngine, processDefId);

        return pde.findActivity(activityId);

    }

    private ProcessDefinitionEntity getProcessDefinition(ProcessEngine processEngine, String processDefId)

    {

        return (ProcessDefinitionEntity) ((RepositoryServiceImpl) processEngine.getRepositoryService())

                .getDeployedProcessDefinition(processDefId);

    }

}