actor-id expression '#{starter}' returned null

定义jbpm工作流程的时候我是通过图形界面工具完成的，下面是我的流程的XML文件
<?xml version="1.0" encoding="UTF-8"?><process-definition 
  xmlns="urn:jbpm.org:jpdl-3.2"
  name="baoxiao">
<start-state name="start">
<task name="start">
<assignment actor-id="#{starter}"></assignment>
</task>
<transition to="apply form" name="to apply form"></transition>
</start-state>
<task-node name="apply form">
<task name="hand">
<assignment actor-id="#{starter}"></assignment>
</task>
<transition to="auditer" name="to audit"></transition>
</task-node> <fork name="audit">
<transition to="manager1" name="to manager1"></transition>
<transition to="manager2" name="to manager2"></transition>
</fork> <task-node name="manager1">
<task name="manager1">
<assignment actor-id="2"></assignment>
<controller class=""></controller>
</task>
<transition to="join1" name="to join1"></transition>
</task-node> <task-node name="manager2">
<task name="manager2">
<assignment actor-id="3"></assignment>
</task>
<transition to="join1" name="to join2"></transition>
</task-node> <join name="join1">
<transition to="boss" name="to boss"></transition>
</join> <task-node name="boss">
<task name="manager3">
<assignment actor-id="4"></assignment>
</task>
<transition to="financial" name="to financial"></transition>
</task-node> <task-node name="financial">
<task name="give">
<assignment actor-id="5"></assignment>
</task>
<transition to="money" name="to money"></transition>
</task-node> <task-node name="auditer">
<task name="audit">
<assignment actor-id="1"></assignment>
</task>
<transition to="audit" name="to fork"></transition>
</task-node> <task-node name="money">
<task name="get">
<assignment actor-id="#{starter}"></assignment>
</task>
<transition to="end" name="to end"></transition>
</task-node>
<end-state name="end"></end-state>
</process-definition>
我是通过下面的程序部署到数据库中的package jbpm.dev.java;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;import junit.framework.TestCase;import org.jbpm.JbpmConfiguration;
import org.jbpm.JbpmContext;
import org.jbpm.graph.def.ProcessDefinition;public class DBProcess extends TestCase { public void testpersistent() throws FileNotFoundException {
JbpmConfiguration config = JbpmConfiguration.getInstance(); 
        JbpmContext jbpmContext = config.createJbpmContext();
        InputStream is = new FileInputStream("src/main/resources/testprocess.xml");
        ProcessDefinition processDefinition = ProcessDefinition.parseXmlInputStream(is); 
        jbpmContext.deployProcessDefinition(processDefinition); 
        jbpmContext.close();
}
}
部署过程中没有报错，但是我发现数据库中jbpm_delegation委托表中没有记录，当执行时会报如题的错误，请大家帮忙看看啊，急