Dear :
when i change websale processdefinition.xml and gpd.xml file task-node name to chinese charactor

processdefinition.xml

<?xml version="1.0" encoding="gb2312"?>
<process-definition name="websale"
 xmlns="urn:jbpm.org:jpdl-3.1">

 <!-- SWIMLANES (= process roles) -->

 <swimlane name="buyer" />

 <swimlane name="salesman">
 <assignment expression="user(ernie)" />
 </swimlane>

 <swimlane name="accountant">
 <assignment expression="user(bert)" />
 </swimlane>

 <swimlane name="shipper">
 <assignment expression="user(grover)" />
 </swimlane>

 <!-- NODES -->

 <start-state name="create new web sale order??">
 <task swimlane="buyer">
 <controller>
 <variable name="item"/>
 <variable name="quantity"/>
 <variable name="address"/>
 </controller>
 </task>
 <transition to="evaluate web order" />
 </start-state>

 <task-node name="evaluate web order">
 <task swimlane="salesman">
 <timer duedate="20 seconds" repeat="10 seconds">
 <action class="org.jbpm.websale.RemindActor">
 <swimlaneName>salesman</swimlaneName>
 </action>
 </timer>
 <controller>
 <variable name="item" access="read"/>
 <variable name="quantity" access="read"/>
 <variable name="address" access="read"/>
 <variable name="comment"/>
 </controller>
 </task>
 <transition name="ok" to="salefork" />
 <transition name="more info needed" to="fix web order data" />
 </task-node>

 <task-node name="fix web order data">
 <task swimlane="buyer">
 <controller>
 <variable name="comment" access="read"/>
 <variable name="item" />
 <variable name="quantity" />
 <variable name="address" />
 </controller>
 </task>
 <transition to="evaluate web order" />
 </task-node>

 <fork name="salefork">
 <transition name="payment" to="wait for money" />
 <transition name="shipping" to="ship item" />
 </fork>

 <task-node name="wait for money">
 <task swimlane="accountant">
 <controller>
 <variable name="item" access="read" />
 <variable name="quantity" access="read" />
 <variable name="address" access="read" />
 <variable name="money received" />
 </controller>
 </task>
 <transition to="update books" />
 </task-node>

 <node name="update books">
 <action class="org.jbpm.websale.UpdateBooks">
 <msg>accountancy application is now informed of the payment</msg>
 </action>
 <transition to="salejoin" />
 </node>

 <node name="ship item">
 <action class="org.jbpm.websale.ShipItem">
 <swimlaneName>shipper</swimlaneName>
 <msg>${shipper} now ships ${item} to ${address}</msg>
 </action>
 <transition to="salejoin" />
 </node>

 <join name="salejoin">
 <transition to="end" />
 </join>

 <end-state name="end" />

</process-definition>

<?xml version="1.0" encoding="gb2312"?>

<process-diagram name="websale" width="639" height="595">
 <node name="create new web sale order??" x="250" y="50" width="200" height="40">
 <transition>
 <label x="5" y="-10"/>
 </transition>
 </node>
 <node name="evaluate web order" x="280" y="125" width="140" height="40">
 <transition name="ok">
 <label x="9" y="-10"/>
 </transition>
 <transition name="more info needed">
 <label x="-44" y="-18"/>
 <bendpoint w1="-114" h1="-35" w2="116" h2="-35"/>
 </transition>
 </node>
 <node name="fix web order data" x="50" y="125" width="140" height="40">
 <transition>
 <label x="5" y="-10"/>
 <bendpoint w1="109" h1="32" w2="-121" h2="32"/>
 </transition>
 </node>
 <node name="salefork" x="250" y="200" width="200" height="25">
 <transition name="payment">
 <label x="12" y="-18"/>
 <bendpoint w1="145" h1="31" w2="0" h2="-52"/>
 </transition>
 <transition name="shipping">
 <label x="10" y="10"/>
 <bendpoint w1="-130" h1="34" w2="0" h2="-89"/>
 </transition>
 </node>
 <node name="wait for money" x="425" y="275" width="140" height="40">
 <transition>
 <label x="5" y="-10"/>
 </transition>
 </node>
 <node name="update books" x="425" y="350" width="140" height="40">
 <transition>
 <label x="5" y="-10"/>
 <bendpoint w1="-1" h1="34" w2="144" h2="-33"/>
 </transition>
 </node>
 <node name="ship item" x="150" y="315" width="140" height="40">
 <transition>
 <label x="5" y="-10"/>
 <bendpoint w1="-1" h1="74" w2="-131" h2="-28"/>
 </transition>
 </node>
 <node name="salejoin" x="250" y="425" width="200" height="25">
 <transition>
 <label x="5" y="-10"/>
 </transition>
 </node>
 <node name="end" x="280" y="500" width="140" height="40"/>
</process-diagram>

I can succesful deploy the process into database,but when i

click the "Start New Process Execution" in home.jsp,

ProcessImageTag.java got an null exception error at the follow line

 Element rootDiagramElement = DocumentHelper.parseText(new String(gpdBytes)).getRootElement();

can anyone help me