jbpm系列之五--使用decision节点判断分支情况

         我们在用JBPM做流程的时候，很多时候会遇到需要判断的节点。类似java中的switch，根据不同的状态，跳转到不同的节点。

         首先我们定义一个流程信息，jpdl流程图如下

 

明显的可以看到，在此种情况下我们就必须用到decision节点来控制不同的业务跳转到不同的角色上。

         我们的jpdl.xml中的代码为：

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

<process key="decision" name="decision" xmlns="http://jbpm.org/4.4/jpdl">
   <start name="start1" g="22,200,48,48">
      <transition name="提交" to="exclusive1" g="-15,-20"/>
   </start>
   <decision name="exclusive1" expr="${node}" g="185,201,48,48">
      <transition name="小于2天" to="组长" g="-49,-32"/>
      <transition name="大于2天,小于10" to="科长" g="-56,-28"/>
      <transition name="10天以上" to="主任" g="-47,-22"/>
   </decision>
   <task assignee="zuzhang" name="组长" g="338,69,92,52">
      <transition name="组长批准" to="归档" g="-51,-26"/>
   </task>
   <task assignee="kezhang" name="科长" g="342,199,92,52">
      <transition name="科长批准" to="归档" g="-49,-25"/>
   </task>
   <task assignee="zhuren" name="主任" g="349,325,92,52">
      <transition name="主任批准" to="归档" g="-41,-25"/>
   </task>
   <task assignee="caiwu" name="归档" g="531,201,92,52">
      <transition name="通过" to="end1" g="-35,-22"/>
   </task>
   <end name="end1" g="689,208,48,48"/>
</process>

    此种方法是定义流程变量，流程变量等于transition中的哪个name的值就跳转到哪个角色中

在代码中：

package com.tgb.node.decision;

import java.util.HashMap;
import java.util.Map;

import org.jbpm.api.ProcessInstance;

import com.tgb.video.JbpmTestCase;
import com.tgb.video.JbpmUtil;

public class TestDecision extends JbpmTestCase implements JbpmUtil {

	@Override
	public void deploy() {
		super.startUp();
		repositoryService.createDeployment().addResourceFromClasspath("com/tgb/node/decision/decision.jpdl.xml").deploy();
	}

	@Override
	public void createInstance() {
		super.startUp();
		Map<String,Object> map = new HashMap<String,Object>();
		map.put("node", "大于2天,小于10");
		ProcessInstance processInstance = executionService.startProcessInstanceByKey("decision", map);
		print("流程实例ID",processInstance.getId());
	}

	@Override
	public void getCurrectActivity() {
		super.startUp();
		String name = executionService.createProcessInstanceQuery().processInstanceId("decision.130001").uniqueResult().findActiveActivityNames().toString();
		print("到达节点名称",name);
	}

	@Override
	public void getTask() {
		// TODO Auto-generated method stub

	}

	@Override
	public void completeTask() {
		// TODO Auto-generated method stub

	}

}

我们只需在代码中控制node的值即可跳转到不同的人员。

第二种：使用表达式判断

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

<process key="decision" name="decision" xmlns="http://jbpm.org/4.4/jpdl">
   <start name="start1" g="22,200,48,48">
      <transition name="提交" to="exclusive1" g="-15,-20"/>
   </start>
   <decision name="exclusive1" g="185,201,48,48">
      <transition name="小于2天" to="组长" g="-49,-32">
      	<condition expr="${days  lt 2}"/>
      </transition>
      <transition name="大于2天,小于10" to="科长" g="-56,-28">
      	<condition expr="${days ge 2 and days le 10}"/>
      </transition>
      <transition name="10天以上" to="主任" g="-47,-22">
      	<condition expr="${days gt 10}"/>
      </transition>
   </decision>
   <task assignee="zuzhang" name="组长" g="338,69,92,52">
      <transition name="组长批准" to="归档" g="-51,-26"/>
   </task>
   <task assignee="kezhang" name="科长" g="342,199,92,52">
      <transition name="科长批准" to="归档" g="-49,-25"/>
   </task>
   <task assignee="zhuren" name="主任" g="349,325,92,52">
      <transition name="主任批准" to="归档" g="-41,-25"/>
   </task>
   <task assignee="caiwu" name="归档" g="531,201,92,52">
      <transition name="通过" to="end1" g="-35,-22"/>
   </task>
   <end name="end1" g="689,208,48,48"/>
</process>

此种方法即把判断放到配置文件中，只需传过一个数字来判断即可。

public void createInstance() {
		super.startUp();
		Map<String,Object> map = new HashMap<String,Object>();
		map.put("days", 15);
		ProcessInstance processInstance = executionService.startProcessInstanceByKey("decision", map);
		print("流程实例ID",processInstance.getId());
	}

创建流程实例代码如上，将参数用days传过来即可判断。

第三种方法：监听判断

写一个类MyDecision，继承DecisionHandler

在jpdl文件中配置上MyDecision，通过复写decide方法，用execution将参数传过来。

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

<process key="decision" name="decision" xmlns="http://jbpm.org/4.4/jpdl">
   <start name="start1" g="22,200,48,48">
      <transition name="提交" to="exclusive1" g="-15,-20"/>
   </start>
   <decision name="exclusive1" g="185,201,48,48">
   	  <handler class="com.tgb.node.decision.MyDecision"/>
      <transition name="到组长" to="组长" g="-49,-32">
      </transition>
      <transition name="到科长" to="科长" g="-56,-28">
      </transition>
      <transition name="到主任" to="主任" g="-47,-22">
      </transition>
   </decision>
   <task assignee="zuzhang" name="组长" g="338,69,92,52">
      <transition name="组长批准" to="归档" g="-51,-26"/>
   </task>
   <task assignee="kezhang" name="科长" g="342,199,92,52">
      <transition name="科长批准" to="归档" g="-49,-25"/>
   </task>
   <task assignee="zhuren" name="主任" g="349,325,92,52">
      <transition name="主任批准" to="归档" g="-41,-25"/>
   </task>
   <task assignee="caiwu" name="归档" g="531,201,92,52">
      <transition name="通过" to="end1" g="-35,-22"/>
   </task>
   <end name="end1" g="689,208,48,48"/>
</process>

MyDecision类中代码：

package com.tgb.node.decision;

import org.jbpm.api.jpdl.DecisionHandler;
import org.jbpm.api.model.OpenExecution;

public class MyDecision implements DecisionHandler {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	@Override
	public String decide(OpenExecution execution) {
		String to = execution.getVariable("to").toString();
		
		if(to.equals("组长")){
			return "到组长";
		}else if (to.endsWith("科长")){
			return "到科长";
		}else{
			return "到主任";
		}
	}
}

         此种方法将判断逻辑交给了java代码，不用重新部署流程。