利用JBPM4.4的AssignmentHandler实现用户角色整合另一种构思

Jbpm4提供的IdentitySession接口并不是一种很好的处理方式，鉴于我们每个业务系统都有一套自己的用户及权限认证管理机制，需要与jbpm4.4集成的话，就比较周折了，我们经常需要查询的就是用户自己的任务。jbpm4的任务里有一个比较好的任务人员指派定义方式，就是使用AssignmentHandler接口，其定义如下所示：

<?xmlversion="1.0"encoding="UTF-8"?>

<processname="TaskAssignmentHandler"xmlns="http://jbpm.org/4.4/jpdl">

<startg="20,20,48,48">
<transitionto="review"/>
</start>

<taskname="review"g="96,16,127,52">
<assignment-handlerclass="org.jbpm.examples.task.assignmenthandler.AssignTask">
<fieldname="assignee">
<stringvalue="johndoe"/>
</field>
</assignment-handler>
<transitionto="wait"/>
</task>

<statename="wait"g="255,16,88,52"/>

</process>

<?xmlversion="1.0"encoding="UTF-8"?>

<processname="TaskAssignmentHandler"xmlns="http://jbpm.org/4.4/jpdl">

<startg="20,20,48,48">
<transitionto="review"/>
</start>

<taskname="review"g="96,16,127,52">
<assignment-handlerclass="org.jbpm.examples.task.assignmenthandler.AssignTask">
<fieldname="assignee">
<stringvalue="johndoe"/>
</field>
</assignment-handler>
<transitionto="wait"/>
</task>

<statename="wait"g="255,16,88,52"/>

</process>

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

<process name="TaskAssignmentHandler" xmlns="http://jbpm.org/4.4/jpdl">

  <start g="20,20,48,48">
    <transition to="review" />
  </start>

  <task name="review" g="96,16,127,52">
    <assignment-handler class="org.jbpm.examples.task.assignmenthandler.AssignTask">
      <field name="assignee">
        <string value="johndoe" />
      </field>
    </assignment-handler>
    <transition to="wait" />
  </task>

  <state name="wait" g="255,16,88,52" />

</process>

packageorg.jbpm.examples.task.assignmenthandler;

importorg.jbpm.api.model.OpenExecution;
importorg.jbpm.api.task.Assignable;
importorg.jbpm.api.task.AssignmentHandler;


/**
*@authorTomBaeyens
*/
publicclassAssignTaskimplementsAssignmentHandler{

privatestaticfinallongserialVersionUID=1L;

Stringassignee;

publicvoidassign(Assignableassignable,OpenExecutionexecution){
assignable.setAssignee(assignee);
}
}

packageorg.jbpm.examples.task.assignmenthandler;

importorg.jbpm.api.model.OpenExecution;
importorg.jbpm.api.task.Assignable;
importorg.jbpm.api.task.AssignmentHandler;


/**
*@authorTomBaeyens
*/
publicclassAssignTaskimplementsAssignmentHandler{

privatestaticfinallongserialVersionUID=1L;

Stringassignee;

publicvoidassign(Assignableassignable,OpenExecutionexecution){
assignable.setAssignee(assignee);
}
}

package org.jbpm.examples.task.assignmenthandler;

import org.jbpm.api.model.OpenExecution;
import org.jbpm.api.task.Assignable;
import org.jbpm.api.task.AssignmentHandler;


/**
 * @author Tom Baeyens
 */
public class AssignTask implements AssignmentHandler {
  
  private static final long serialVersionUID = 1L;

  String assignee;

  public void assign(Assignable assignable, OpenExecution execution) {
    assignable.setAssignee(assignee);
  }
}

这要求我们在设计流程定义后，任务的处理人已经必须定下来了，但若我们在流程发布后，还需要手工改这里的任务执行人员（并且人员是我们系统的用户），甚至人员可能在流程运行过程中，由用户在任务表单或计算过程中动态指定，以上的方式并不能满足我们的要求。

基于这种想法，应该设计另一种允许用户修改流程定义中的人员，并且跟我们的系统用户角色结合起来。

jbpm4之后的版本，启动流程及运行流程时，都会去读取流程定义，因此，我们可以动态修改以上配置文件，让其生成类似如下的配置格式即可以满足我们的要求：

<?xmlversion="1.0"encoding="UTF-8"?>

<processname="TaskAssignmentHandler"xmlns="http://jbpm.org/4.4/jpdl">

<startg="20,20,48,48">
<transitionto="review"/>
</start>

<taskname="review"g="96,16,127,52">
<assignment-handlerclass="com.htsoft.core.jbpm.AssignmentHandler">
<fieldname="userIds">
<stringvalue="1"/>
</field>
<fieldname="roleIds">
<stringvalue="1,2"/>
</field>
</assignment-handler>
<transitionto="wait"/>
</task>

<statename="wait"g="255,16,88,52"/>

</process>

<?xmlversion="1.0"encoding="UTF-8"?>

<processname="TaskAssignmentHandler"xmlns="http://jbpm.org/4.4/jpdl">

<startg="20,20,48,48">
<transitionto="review"/>
</start>

<taskname="review"g="96,16,127,52">
<assignment-handlerclass="com.htsoft.core.jbpm.AssignmentHandler">
<fieldname="userIds">
<stringvalue="1"/>
</field>
<fieldname="roleIds">
<stringvalue="1,2"/>
</field>
</assignment-handler>
<transitionto="wait"/>
</task>

<statename="wait"g="255,16,88,52"/>

</process>

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

<process name="TaskAssignmentHandler" xmlns="http://jbpm.org/4.4/jpdl">

  <start g="20,20,48,48">
    <transition to="review" />
  </start>

  <task name="review" g="96,16,127,52">
    <assignment-handler class="com.htsoft.core.jbpm.AssignmentHandler">
      <field name="userIds">
        <string value="1" />
      </field>
     <field name="roleIds">
        <string value="1,2" />
      </field>
    </assignment-handler>
    <transition to="wait" />
  </task>

  <state name="wait" g="255,16,88,52" />

</process>

以上的userIds的1，以及roleIds的1,2则代表我们系统中的用户id与角色的id，其值由后台用户在后面通过界面来设置。

其设置后，就生成以上的代码写至jbpm4_lob表中的blobvalue字段中去则可，这是持久化的处理。

也可以临时调用类似以下的代码动态实现以上效果：

/**
*为流程定义加上任务的指派人员接口
*@paramdeployId
*/
publicvoidaddAssignHandler(ProUserAssignproUserAssign){
ProcessDefinitionImplpd=(ProcessDefinitionImpl)repositoryService.createProcessDefinitionQuery().deploymentId(proUserAssign.getDeployId()).uniqueResult();
EnvironmentFactoryenvironmentFactory=(EnvironmentFactory)processEngine;
EnvironmentImplenv=null;
try{
env=environmentFactory.openEnvironment();
//找到任务的定义
TaskDefinitionImpltaskDef=pd.getTaskDefinition(proUserAssign.getActivityName());
UserCodeReferenceuserCodeReference=newUserCodeReference();
ObjectDescriptordescriptor=newObjectDescriptor();
//加上任务的人员动态指派
descriptor.setClassName("com.htsoft.core.jbpm.UserAssignHandler");
//动态加参数
FieldOperationuserIdsFo=newFieldOperation();
userIdsFo.setFieldName("userIds");
userIdsFo.setDescriptor(newStringDescriptor(proUserAssign.getUserId()));

FieldOperationgroupIdsFo=newFieldOperation();
groupIdsFo.setFieldName("groupIds");
groupIdsFo.setDescriptor(newStringDescriptor(proUserAssign.getRoleId()));

List<Operation>listOp=newArrayList<Operation>();
listOp.add(userIdsFo);
listOp.add(groupIdsFo);
descriptor.setOperations(listOp);

userCodeReference.setCached(false);
userCodeReference.setDescriptor(descriptor);
taskDef.setAssignmentHandlerReference(userCodeReference);

}catch(Exceptionex){
logger.error("ADDAssignHandlerError:"+ex.getMessage());
}finally{
if(env!=null){
env.close();
}
}
}

/**
*为流程定义加上任务的指派人员接口
*@paramdeployId
*/
publicvoidaddAssignHandler(ProUserAssignproUserAssign){
ProcessDefinitionImplpd=(ProcessDefinitionImpl)repositoryService.createProcessDefinitionQuery().deploymentId(proUserAssign.getDeployId()).uniqueResult();
EnvironmentFactoryenvironmentFactory=(EnvironmentFactory)processEngine;
EnvironmentImplenv=null;
try{
env=environmentFactory.openEnvironment();
//找到任务的定义
TaskDefinitionImpltaskDef=pd.getTaskDefinition(proUserAssign.getActivityName());
UserCodeReferenceuserCodeReference=newUserCodeReference();
ObjectDescriptordescriptor=newObjectDescriptor();
//加上任务的人员动态指派
descriptor.setClassName("com.htsoft.core.jbpm.UserAssignHandler");
//动态加参数
FieldOperationuserIdsFo=newFieldOperation();
userIdsFo.setFieldName("userIds");
userIdsFo.setDescriptor(newStringDescriptor(proUserAssign.getUserId()));

FieldOperationgroupIdsFo=newFieldOperation();
groupIdsFo.setFieldName("groupIds");
groupIdsFo.setDescriptor(newStringDescriptor(proUserAssign.getRoleId()));

List<Operation>listOp=newArrayList<Operation>();
listOp.add(userIdsFo);
listOp.add(groupIdsFo);
descriptor.setOperations(listOp);

userCodeReference.setCached(false);
userCodeReference.setDescriptor(descriptor);
taskDef.setAssignmentHandlerReference(userCodeReference);

}catch(Exceptionex){
logger.error("ADDAssignHandlerError:"+ex.getMessage());
}finally{
if(env!=null){
env.close();
}
}
}

/**
     * 为流程定义加上任务的指派人员接口
     * @param deployId
     */
    public void addAssignHandler(ProUserAssign proUserAssign){
    	ProcessDefinitionImpl pd=(ProcessDefinitionImpl)repositoryService.createProcessDefinitionQuery().deploymentId(proUserAssign.getDeployId()).uniqueResult();
    	 EnvironmentFactory environmentFactory = (EnvironmentFactory) processEngine;
		 EnvironmentImpl env=null;
		 try {
			 env = environmentFactory.openEnvironment();
			 //找到任务的定义
			 TaskDefinitionImpl taskDef=pd.getTaskDefinition(proUserAssign.getActivityName());
			 UserCodeReference userCodeReference = new UserCodeReference();
			 ObjectDescriptor descriptor = new ObjectDescriptor();
			 //加上任务的人员动态指派
			 descriptor.setClassName("com.htsoft.core.jbpm.UserAssignHandler");
			 //动态加参数
			 FieldOperation userIdsFo = new FieldOperation();
			 userIdsFo.setFieldName("userIds");	
			 userIdsFo.setDescriptor(new StringDescriptor(proUserAssign.getUserId()));
			 
			 FieldOperation groupIdsFo=new FieldOperation();
			 groupIdsFo.setFieldName("groupIds");
			 groupIdsFo.setDescriptor(new StringDescriptor(proUserAssign.getRoleId()));
			 
			 List<Operation> listOp=new ArrayList<Operation>();
			 listOp.add(userIdsFo);
			 listOp.add(groupIdsFo);
			 descriptor.setOperations(listOp);
			 
			 userCodeReference.setCached(false);
			 userCodeReference.setDescriptor(descriptor);
			 taskDef.setAssignmentHandlerReference(userCodeReference);
			 
		 }catch(Exception ex){
			 logger.error("ADD AssignHandler Error:" + ex.getMessage());
		 }finally{
			 if(env!=null){
				 env.close();
			 }
		 }
    }

不过该方式没有持久久，重启系统后，保存的用户及角色设置并不会生效。

UserAssignHandler类代码如下：

packagecom.htsoft.core.jbpm;

importorg.apache.commons.lang.StringUtils;
importorg.apache.commons.logging.Log;
importorg.apache.commons.logging.LogFactory;
importorg.jbpm.api.model.OpenExecution;
importorg.jbpm.api.task.Assignable;
importorg.jbpm.api.task.AssignmentHandler;

importcom.htsoft.core.Constants;

/**
*尚未开始使用
*<B><P>Joffice--http://www.jee-soft.cn</P></B>
*<B><P>Copyright(C)2008-2010GuangZhouHongTianSoftwareCompany(广州宏天软件有限公司)</P></B>
*<B><P>description:</P></B>
*<P></P>
*<P>product:joffice</P>
*<P></P>
*@seecom.htsoft.core.jbpm.UserAssignHandler
*<P></P>
*@author
*@versionV1
*@create:2010-11-23下午02:58:01
*/
publicclassUserAssignHandlerimplementsAssignmentHandler{
privateLoglogger=LogFactory.getLog(UserAssignHandler.class);
//授予用户ID
StringuserIds;
//授权角色ID
StringgroupIds;

@Override
publicvoidassign(Assignableassignable,OpenExecutionexecution)throwsException{

StringassignId=(String)execution.getVariable(Constants.FLOW_ASSIGN_ID);

logger.info("assignId:===========>"+assignId);

//在表单提交中指定了固定的执行人员
if(StringUtils.isNotEmpty(assignId)){
assignable.setAssignee(assignId);
return;
}

//在表单中指定了执行的角色TODO

//在表单中指定了会签人员
StringsignUserIds=(String)execution.getVariable(Constants.FLOW_SIGN_USERIDS);

if(signUserIds!=null){
//TODO取到该任务,进行会签设置
}

logger.debug("EnterUserAssignHandlerassignmethod~~~~");

if(userIds!=null){//若用户不为空
String[]uIds=userIds.split("[,]");
if(uIds!=null&&uIds.length>1){//多于一个人的
for(StringuId:uIds){
assignable.addCandidateUser(uId);
}
}else{
assignable.setAssignee(userIds);
}
}

if(groupIds!=null){//若角色组不为空
String[]gIds=userIds.split("[,]");
if(gIds!=null&&gIds.length>1){//多于一个角色的
for(StringgId:gIds){
assignable.addCandidateGroup(gId);
}
}else{
assignable.addCandidateGroup(groupIds);
}
}

}

}