Tran

package cn.cslg.shally.manager.impl;

import java.util.Iterator;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.jbpm.graph.def.ActionHandler;
import org.jbpm.graph.def.Node;
import org.jbpm.graph.def.Transition;
import org.jbpm.graph.exe.ExecutionContext;
import org.jbpm.graph.node.EndState;

public class CreateTransitionAction implements ActionHandler {

 private Log logger = LogFactory.getLog(CreateTransitionAction.class);
 public static final String BACK_TRANSITION = "回退";
 
 public void execute(ExecutionContext executionContext) throws Exception {
  logger.debug("进入Action");
  
  //如果当前节点是在结束节点，则无需创建任何返回Transition
  if(executionContext.getNode() instanceof EndState){
   return;
  }
  
  boolean ignore = false;
  
  //得到当前指向的节点所有可以使用的transition对象列表
  Set ts = executionContext.getToken().getAvailableTransitions();
  for (Iterator iterator = ts.iterator(); iterator.hasNext();) {
   Transition t = (Transition) iterator.next();
   if(t.getName().equals(BACK_TRANSITION)){
    ignore = true;
    break;
   }
  }
  
  //如果尚未创建回退Transition对象，就可以继续创建
  if(!ignore){
   String preNodeName = (String)executionContext.getContextInstance().getVariable("preNodeName");
   if(preNodeName != null){ //前一个节点非空，需要创建回退Transition
    
    //从当前节点
    Node from = executionContext.getNode();
    
    //将上一个节点作为终点
    Node to = executionContext.getProcessDefinition().getNode(preNodeName);
    
    //创建回退Transition对象
    Transition transition = new Transition();
    transition.setName(BACK_TRANSITION);
    transition.setDescription("自动生成的回退Transition对象");
    from.addLeavingTransition(transition);
    to.addArrivingTransition(transition);
   }
   executionContext.getContextInstance().setVariable("preNodeName", executionContext.getNode().getName());
  }
  
 }

}