org.dom4j.DocumentException: null Nested exception: null

public class JbpmTest {
    bpmConfiguration jbpmConfiguration = JbpmConfiguration.getInstance();
    public void testJbpm(){
    ProcessDefinition processDefinition = ProcessDefinition.parseXmlResource("gmanage/processdefinition.xml");
JbpmContext jbpmContext = jbpmConfiguration.createJbpmContext();
  try{
    jbpmContext.deployProcessDefinition(processDefinition);
   System.out.println("流程部署成功！");
  }finally{
      jbpmContext.close();
  }
 }
public static void main(String args[]){
JbpmTest jt=new JbpmTest();
jt.testJbpm();
}}org.dom4j.DocumentException: null Nested exception: null
at org.dom4j.io.SAXReader.read(SAXReader.java:484)
at org.jbpm.jpdl.xml.JpdlParser.parse(JpdlParser.java:57)
at org.jbpm.jpdl.xml.JpdlXmlReader.readProcessDefinition(JpdlXmlReader.java:138)
at org.jbpm.graph.def.ProcessDefinition.parseXmlInputStream(ProcessDefinition.java:172)
at org.jbpm.graph.def.ProcessDefinition.parseXmlResource(ProcessDefinition.java:153)
at cn.cc.servlet.JbpmTest.testJbpm(JbpmTest.java:18)
at cn.cc.servlet.JbpmTest.main(JbpmTest.java:35)知道是ProcessDefinition processDefinition = ProcessDefinition.parseXmlResource("gmanage/processdefinition.xml");这行的错误不知道怎么解决，求救！！