JBPM4.4(2)-state结点和decision结点

做一个带有分支的流向流程

在执行seperate状态的时候分成了200和400两种情况

描述文件的内容如下：

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

<process name="fork" xmlns="http://jbpm.org/4.4/jpdl">
 <start g="237,28,48,48" name="start1">
 <transition name="to separate" to="separate" g="-71,-17"/>
 </start>
 <state g="210,153,92,52" name="separate">
 <transition name="to 200" to="200" g="-41,-17"/>
 <transition name="to 400" to="400" g="-41,-17"/>
 </state>
 <state g="145,256,92,52" name="200">
 <transition name="to end1" to="end1" g="-47,-17"/>
 </state>
 <state g="306,255,92,52" name="400">
 <transition name="to end1" to="end1" g="-47,-17"/>
 </state>
 <end g="245,375,48,48" name="end1"/>
</process>

public class TestSperator extends JbpmTestCase {

 String deploymentId;

 protected void setUp() throws Exception {
 super.setUp();

 deploymentId = repositoryService.createDeployment()
 .addResourceFromClasspath("com/jbpm/fork/fork.jpdl.xml")
 .deploy();
 }

 protected void tearDown() throws Exception {
 repositoryService.deleteDeploymentCascade(deploymentId);

 super.tearDown();
 }

 public void testSeparate() {
 ProcessInstance processInstance = executionService
 .startProcessInstanceByKey("fork");

 System.out.println("流程实例Id:" + processInstance.getId());
 System.out.println("流程定义Id:" + processInstance.getProcessDefinitionId());

 ProcessInstance instance = executionService.signalExecutionById(processInstance.getId());

 // 判断当前是否位于state节点

 System.out.println("是否位于state节点:" + instance.isActive("separate"));
 System.out.println("向下执行...");
 
 ProcessInstance processInstance200=executionService.signalExecutionById(processInstance.getId(), "to 200");

 System.out.println("当前流程是否位于200节点---->"+processInstance200.isActive("200"));
 System.out.println("当前流程是否结束---->"+processInstance200.isEnded());
 
 ProcessInstance endinstance=executionService.signalExecutionById(processInstance200.getId());

 System.out.println("当前流程是否结束---->"+endinstance.isEnded());


 }
}

执行流程的结果如下：

使流程向下执行

executionService.signalExecutionById();

该方法有多个重载:

注:当一个节点有多个分支时,若要通过signalExecutionById()方法将流程向下执行必须明确指出signalName即(transition的name属性所指的方向),否则流程不会向下执行，仍会停留在当前节点。因为jbpm不确定流程该流向那个方向。

接下来是一个decision的例子，这个是一个分支判断的节点，相当于我们程序中的switch case

下面画一个选择向左还是向右的例子

定义文件如下：

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

<process name="decision" xmlns="http://jbpm.org/4.4/jpdl">
 <start g="246,30,48,48" name="start1">
 <transition name="to wait" to="wait" g="-47,-17"/>
 </start>
 <state g="231,112,92,52" name="wait">
 <transition name="to exclusive1" to="exclusive1" g="-83,-17"/>
 </state>
 <decision g="252,204,48,48" name="exclusive1">
 <transition name="to left" to="left" g="-47,-17">
 <condition expr="${coder=='left'}"></condition>
 </transition>
 <transition name="to right" to="right" g="-53,-17">
 <condition expr="${coder=='right'}"></condition>
 </transition>
 </decision>
 <state g="175,295,92,52" name="left">
 <transition name="to end1" to="end1" g="-47,-17"/>
 </state>
 <state g="325,292,92,52" name="right">
 <transition name="to end1" to="end1" g="-47,-17"/>
 </state>
 <end g="268,370,48,48" name="end1"/>
</process>

其中有几种方式可以处理流程的走向

第一种，内置条件

即在流程定义中设置每一个transition的子节点condition,并为每一个condition填充expr属性

形如:

<condition expr="${coder=='left'}"></condition>

对应的测试流程如下，需要增加

Map<String, String> map=new HashMap<String, String>();
 //coder为流程定义中表达式的名称
 map.put("coder", "left");
 
 ProcessInstance processInstance = executionService.startProcessInstanceByKey("decision",map);

如果map中order的值指定的有问题那么就会抛出异常

测试程序如下：

public class TestDecision extends JbpmTestCase {

 String deploymentId;

 protected void setUp() throws Exception {
 super.setUp();

 deploymentId = repositoryService.createDeployment()
 .addResourceFromClasspath("com/jbpm/decision/decision.jpdl.xml")
 .deploy();
 }

 protected void tearDown() throws Exception {
 repositoryService.deleteDeploymentCascade(deploymentId);

 super.tearDown();
 }

 public void testDescsion() {
 
 Map<String, String> map=new HashMap<String, String>();
 //coder为流程定义中表达式的名称
 map.put("coder", "left");
 
 ProcessInstance processInstance = executionService.startProcessInstanceByKey("decision",map);

 System.out.println("流程实例Id:" + processInstance.getId());
 System.out.println("流程定义Id:" + processInstance.getProcessDefinitionId());
 
 System.out.println("是否位于state节点:" + processInstance.isActive("wait"));

 ProcessInstance decisionInstance = executionService.signalExecutionById(processInstance.getId());

 // 判断当前是否位于wait节点
 System.out.println("是否位于wait节点:" + decisionInstance.isActive("wait"));
 System.out.println("因为已经有值所以自动向下执行...");
 System.out.println("是否位于left节点:" + decisionInstance.isActive("left"));
 
 //向下执行
 ProcessInstance endinstance=executionService.signalExecutionById(decisionInstance.getId());

 System.out.println("当前流程是否结束---->"+endinstance.isEnded());

 }
}

执行结果如图所示：

因为在开始的时候指定了流程处理的方向，所以流程向left方向自动执行。

第二种，更像switch case

在decision节点上指定

<decision g="252,204,48,48" name="exclusive1" expr="${toWhere}">

修改代码为：

Map<String, String> map=new HashMap<String, String>();
 //coder为流程定义中表达式的名称
 map.put("toWhere", "to left");

其它部分不变，可以看到结果和原来的相同。

第三种，配置handler子类

在流程定义中在decision节点内部配置<handler/>子节点,并设置该元素的class属性为你自己的类)该类实现了org.jbpm.api.jpdl.DecisionHandler.你需要重写

String decide(OpenExecution execution);方法即可,在该方法最终返回decision活动后的下一个transition的name属性的值。

修改配置文件

<decision g="252,204,48,48" name="exclusive1">
 <handler class="com.jbpm.decision.HandlerDecision"></handler>
 <transition name="to left" to="left" g="-47,-17">
 </transition>
 <transition name="to right" to="right" g="-53,-17">
 </transition>
 </decision>

添加HandlerDecision并且实现DecisionHandler

代码如下：

@SuppressWarnings("serial")
public class HandlerDecision implements DecisionHandler {

 @Override
 public String decide(OpenExecution execution) {
 // TODO Auto-generated method stub
 String toWhere = execution.getVariable("toWhere").toString();
 String result = null;

 if ("left".equals(toWhere)) {
 result = "to left";
 } else if ("right".equals(toWhere)) {
 result = "to right";
 }
 return result;
 }

}

Map<String, String> map=new HashMap<String, String>();
 //coder为流程定义中表达式的名称
 map.put("toWhere", "left");