JBPM 中的decision 使用

在JBPM中我们经常需要动态的决定业务流程的走向,JBPM本身提供了Decision这个标签让我们可以通过expression来动态的决定流程应该如何路由.下面给出了一个非常简单的使用Decision的例子

xml定义流程图

xml定义文件:

<?xml version="1.0" encoding="UTF-8"?>

<process-definition xmlns="urn:jbpm.org:jpdl-3.2" name="decisiontest">
    <start-state name="start">
        <transition name="" to="task1"></transition>
    </start-state>
    <end-state name="end1"></end-state>
    <task-node name="task1">
    <task></task>
        <transition name="" to="decision1"></transition>
    </task-node>
    <decision name="decision1" expression="#{role=='tr1'?'tr1':'tr2'}">
        <transition name="tr1" to="task2"></transition>
        <transition name="tr2" to="task3"></transition>
    </decision>
    <task-node name="task2">
        <task></task>
        <transition name="" to="end1"></transition>
    </task-node>
    <task-node name="task3">
        <task></task>
        <transition name="" to="end1"></transition>
    </task-node>
</process-definition>

 

java测试代码:

package com.decision;

import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.graph.exe.ProcessInstance;

import junit.framework.TestCase;

public class DecisionTest extends TestCase ...{
    ProcessDefinition procdef;
    ProcessInstance procInstance;
    
    @Override
    protected void setUp() throws Exception ...{
        // TODO Auto-generated method stub
        super.setUp();
       procdef=ProcessDefinition.parseXmlResource("decision/decisiontest/processdefinition.xml");
       procInstance=new ProcessInstance(procdef);
    }

    @Override
    protected void tearDown() throws Exception ...{
        // TODO Auto-generated method stub
        super.tearDown();
    }

    public void testProcess()...{
        assertEquals("start", procInstance.getRootToken().getNode().getName());
        procInstance.signal();
        assertEquals("task1",procInstance.getRootToken().getNode().getName());
        procInstance.getContextInstance().setVariable("role", "tr2");
        procInstance.signal();
        assertEquals("task2",procInstance.getRootToken().getNode().getName());
        assertEquals("tr1", (String)procInstance.getContextInstance().getVariable("role"));
        procInstance.signal();
        assertTrue(procInstance.hasEnded());
    }
}

来自网络转载，不过测试了下，用的junit测试，发现运行通不过去，老报空指针异常，有知道原因的请告诉我