使用JBPM实现动态会签

目前有很多实现动态会签的文章，但是给人感觉不是很优雅，下面介绍一种实现方式。
1、流程定义文件：

xml 代码

< process-definition
xmlns = "urn:jbpm.org:jpdl-3.1"   name = "foreach" >
< start-state   name = "start" >
< task   name = "one" >
</ task >
< transition   name = "a"   to = "foreachf" > </ transition >
</ start-state >
< node   name = "foreachf" >
< action   class = "com.framework.workflow.jbpm.ForEachFork" >
< foreach > #{bpm_assignees} </ foreach >
< var > reviewer </ var >
</ action >
< transition   name = "review"   to = "review" > </ transition >
</ node >
< task-node   name = "review" >
< task   name = "reviewTask" >
< assignment   class = "com.framework.workflow.jbpm.DefaultAssignment" >
< actor > #{reviewer} </ actor >
</ assignment >
</ task >
< transition   name = "reject"   to = "endreview" >
< action   class = "com.framework.workflow.jbpm.JoinEndForkedTokens"   />
</ transition >
< transition   name = "approve"   to = "endreview" > </ transition >
</ task-node >
< join   name = "endreview" >
< transition   name = "toend"   to = "end1" > </ transition >
</ join >
< end-state   name = "end1" > </ end-state >
</ process-definition >

在这里我们从node节点动态生成任务节点，会签时当有一个是reject时便结束所有节点。
2、动态派生ForEachFork代码：

java 代码

public   class  ForEachFork  implements  ActionHandler
{
private  Element foreach;
private  String var;
//测试数据
private   static  Map map =  new  HashMap();
static {
List list = new  ArrayList();
list.add("1234" );
list.add("2345" );
list.add("3456" );
map.put("bpm_assignees" , list);
}

/**
*

为每个元素创建一个分支

*
* @param executionContext
* @throws Exception
*/
@SuppressWarnings ( "unchecked" )
public   void  execute( final  ExecutionContext executionContext)
throws  Exception
{


if  (foreach ==  null )
{
throw   new  WorkflowException( "forEach has not been provided" );
}

List forEachColl = null ;
String forEachCollStr = foreach.getTextTrim();

if  (forEachCollStr !=  null )
{
if  (forEachCollStr.startsWith( "#{" ))
{
String expression = forEachCollStr.substring(2 , forEachCollStr.length() - 1 );
forEachColl = (List)map.get(expression);

}

}

if  (var ==  null  || var.length() ==  0 )
{
throw   new  WorkflowException( "forEach variable name has not been provided" );
}

//
// 创建分支
//

Token rootToken = executionContext.getToken();
Node node = executionContext.getNode();
List forkTransitions = new  ArrayList();
// 为每一个元素创建一个token
for  ( int  i =  0 ; i < node.getLeavingTransitions().size(); i++)
{
Transition transition = (Transition) node.getLeavingTransitions().get(i);
for  ( int  iVar =  0 ; iVar < forEachColl.size(); iVar++)
{
// 为每一个新token创建一个path
String tokenName = getTokenName(rootToken, transition.getName(), iVar);
Token loopToken = new  Token(rootToken, tokenName);
loopToken.setTerminationImplicit(true );
executionContext.getJbpmContext().getSession().save(loopToken);

//赋予一个新变量
final  ExecutionContext newExecutionContext =  new  ExecutionContext(loopToken);
newExecutionContext.getContextInstance().createVariable(var, forEachColl.get(iVar), loopToken);

// 记录下每一transition
ForkedTransition forkTransition = new  ForkedTransition();
forkTransition.executionContext = newExecutionContext;
forkTransition.transition = transition;
forkTransitions.add(forkTransition);
}
}
//
// 转向下一个节点
//
for  (ForkedTransition forkTransition : forkTransitions)
{
node.leave(forkTransition.executionContext, forkTransition.transition);
}
}
/**
*

获得分支token name

*
* @param parent
* @param transitionName
* @return
*/
protected  String getTokenName(Token parent, String transitionName,  int  loopIndex)
{
String tokenName = null ;
if  (transitionName !=  null )
{
if  (!parent.hasChild(transitionName))
{
tokenName = transitionName;
}
else
{
int  i =  2 ;
tokenName = transitionName + Integer.toString(i);
while  (parent.hasChild(tokenName))
{
i++;
tokenName = transitionName + Integer.toString(i);
}
}
}
else
{
// 没有转向
int  size = ( parent.getChildren()!= null  ? parent.getChildren().size()+ 1  :  1  );
tokenName = Integer.toString(size);
}
return  tokenName +  "."  + loopIndex;
}



/**
* Fork Transition
*/
private   class  ForkedTransition
{
private  ExecutionContext executionContext;
private  Transition transition;
}
}

 

 

在具体应用中需要灵活的根据业务逻辑需要派生所需要的分支。

 

3、DefaultAssignment
进行简单的权限操作，这里面主要是将#{reviewer}值作为actorId进行设置
4、JoinEndForkedTokens结束所有节点

java 代码

public   class  JoinEndForkedTokens  implements  ActionHandler
{

public  JoinEndForkedTokens()
{
}
/* (non-Javadoc)
* @see org.jbpm.graph.def.ActionHandler#execute(org.jbpm.graph.exe.ExecutionContext)
*/
public   void  execute(ExecutionContext executionContext)
{
Token token = executionContext.getToken().getParent();
Map childTokens = token.getActiveChildren();
for  (Object childToken : childTokens.values())
{
cancelToken(executionContext, (Token)childToken);
}

}
/**
*

取消 token

*
* @param executionContext
* @param token
*/
protected   void  cancelToken(ExecutionContext executionContext, Token token)
{

Map childTokens = token.getActiveChildren();
for  (Object childToken : childTokens.values())
{
cancelToken(executionContext, (Token)childToken);
}

if  (!token.hasEnded())
{
token.end(true );
}


cancelTokenTasks(executionContext, token);
}
/**
*

结束token关联的任务

*
* @param executionContext
* @param token
*/
protected   void  cancelTokenTasks(ExecutionContext executionContext, Token token)
{
TaskMgmtInstance tms = executionContext.getTaskMgmtInstance();
Collection tasks = tms.getUnfinishedTasks(token);
for  (Object task : tasks)
{
TaskInstance taskInstance = (TaskInstance)task;
if  (taskInstance.isBlocking())
{
taskInstance.setBlocking(false );
}
if  (taskInstance.isSignalling())
{
taskInstance.setSignalling(false );
}
if  (!taskInstance.hasEnded())
{
taskInstance.end();
}
}
}
}

 

 

结束所有分支节点任务，流向结束节点。