使用fork/join的常见错误

在实际的流程设计中常常会出现如下的流程：

看上去没什么问题，那么开始编程

xml 代码

<!---->xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="" name="yytest">
   <start-state name="start">
      <transition name="" to="f1">transition>
   start-state>
   <fork name="f1">
      <transition name="to_s1" to="s1">transition>
      <transition name="to_j1_1" to="j1">transition>
   fork>
   <state name="s1">
      <transition name="" to="f2">transition>
   state>
   <fork name="f2">
      <transition name="to_j1_2" to="j1">transition>
      <transition name="to_s2" to="s2">transition>
   fork>
   <state name="s2">
      <transition name="to_j1_3" to="j1">transition>
   state>
   <join name="j1">
      <transition name="" to="s3">transition>
   join>
   <state name="s3">
      <transition name="" to="end">transition>
   state>
   <end-state name="end">end-state>

process-definition>

java 代码

private static void run(){
        JbpmContext jbpmContext = jbpmConfiguration.createJbpmContext();
        try {
            long processInstanceId =1;
               processInstance = jbpmContext.loadProcessInstance(processInstanceId);
               Token root = processInstance.getRootToken();
               root.signal();
               Token to_s1 = root.getChild("to_s1");
               Token to_j1_1 = root.getChild("to_j1_1");
               System.out.println("root:"+root.getNode());//root:Fork(f1)
               System.out.println("to_s1:"+to_s1.getNode());//to_s1:State(s1)
               System.out.println("to_j1_1:"+to_j1_1.getNode());//to_j1_1:Join(j1)
               to_s1.signal();
               Token to_s2 = to_s1.getChild("to_s2");
               Token to_j1_2 = to_s1.getChild("to_j1_2");
               System.out.println("root:"+root.getNode());//root:Fork(f1)
               System.out.println("to_s2:"+to_s2.getNode());//to_s2:State(s2)
               System.out.println("to_j1_2:"+to_j1_2.getNode());//to_j1_2:Join(j1)
               to_s2.signal();
               System.out.println("root:"+root.getNode());
               //注意这里，我们的目的是所有的分支已经结束，root应该到达Join(j1)。但是实际运行结果为root:Fork(f1)
            }finally {
              jbpmContext.close();
            }

    }

为什么所有的子令牌都结束了，根令牌仍然在fork呢？原因就是fork和join没有配对使用。所以看似正确的流程也一定要经过严格的测试，绝不能想当然。重新编写流程定义文件：

xml 代码

<!---->xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="" name="yytest">
   <start-state name="start">
      <transition name="" to="f1">transition>
   start-state>
   <fork name="f1">
      <transition name="to_s1" to="s1">transition>
      <transition name="to_j1_1" to="j1">transition>
   fork>
   <state name="s1">
      <transition name="" to="f2">transition>
   state>
   <fork name="f2">
      <transition name="to_j2_1" to="j2">transition>
      <transition name="to_s2" to="s2">transition>
   fork>
   <state name="s2">
      <transition name="to_j2_2" to="j2">transition>
   state>
   <join name="j2">
        <transition name="to_j1_2" to="j1">transition>
   join>
   <join name="j1">
      <transition name="" to="s3">transition>
   join>
   <state name="s3">
      <transition name="" to="end">transition>
   state>
   <end-state name="end">end-state>


process-definition>

java 代码

private static void run(){
        JbpmContext jbpmContext = jbpmConfiguration.createJbpmContext();
        try {
            long processInstanceId =1;
               processInstance = jbpmContext.loadProcessInstance(processInstanceId);
               Token root = processInstance.getRootToken();
               root.signal();
               Token to_s1 = root.getChild("to_s1");
               Token to_j1_1 = root.getChild("to_j1_1");
               System.out.println("root:"+root.getNode());//root:Fork(f1)
               System.out.println("to_s1:"+to_s1.getNode());//to_s1:State(s1)
               System.out.println("to_j1_1:"+to_j1_1.getNode());//to_j1_1:Join(j1)
               to_s1.signal();
               Token to_s2 = to_s1.getChild("to_s2");
               Token to_j2_1 = to_s1.getChild("to_j2_1");
               System.out.println("root:"+root.getNode());//root:Fork(f1)
               System.out.println("to_s2:"+to_s2.getNode());//to_s2:State(s2)
               System.out.println("to_j2_1:"+to_j2_1.getNode());//to_j2_1:Join(j1)
               to_s2.signal();
               System.out.println("root:"+root.getNode());
               //正确：root:State(s3)
            }finally {
              jbpmContext.close();
            }

    }

评论

2 楼 jeffen2006 2006-12-05  

如何上传呢？我点插入图片的按钮，弹出的对话框中没有上传的功能，我就copy的地址。

1 楼 抛出异常的爱 2006-12-05  

D:/eclipse/jbpm/jbpm-starters-kit-3.1.2/jbpm-designer/workspace/yytestjbpm/processes/yytest/processimage.jpg

注意先上传之后再用网络URL引用图片