JBoss jBPM(Workflow Management Engine)備忘記

<transition name="to_end" to="end">

About to finish!

</transition>

這裡描述 first 點. 通過此點將過渡至 end 點.
而過渡至 end 點時會觸發 com.sample.action.MessageActionHandler [後面會介紹]
並設定此 ActionHandler 的 message 為 "About to finish!"

流程結速點.

右鍵點選 processdefinition.xml -> Open With -> jBPM Graphical Process Designer
然後點 Diagram , 就會出現如下圖所示


可以使用 GPD (Graphical Process Designer) 來繪製 workflow
為了簡化備忘記, 參考以下官方教學文檔
http://docs.jboss.com/jbpm/v3/gpd

/*------------------ MessageActionHandler.java -------------------*/
package com.sample.action;
import org.jbpm.graph.def.ActionHandler;
import org.jbpm.graph.exe.ExecutionContext;
public class MessageActionHandler implements ActionHandler {
// 這是 Listener, 觸發這個 Action 將執行 execute method
private static final long serialVersionUID = 1L;

String message;

public void execute(ExecutionContext context) throws Exception {
context.getContextInstance().setVariable("message", message);
// 這裡將上面觸發的 message 加入到該點的 message property
}

}
/*------------------ MessageActionHandler.java -------------------*/

/*------------------ SimpleProcessTest.java -------------------*/
package com.sample;
import java.io.FileInputStream;
import junit.framework.TestCase;
import org.jbpm.graph.def.ProcessDefinition;
import org.jbpm.graph.exe.ProcessInstance;
public class SimpleProcessTest extends TestCase {

public void testSimpleProcess() throws Exception {

FileInputStream fis = new FileInputStream("processes/simple/processdefinition.xml");
ProcessDefinition processDefinition = ProcessDefinition.parseXmlInputStream(fis);
// 讀取 processdefinition.xml 的流程定義檔

assertNotNull("Definition should not be null", processDefinition);
// 測試這個檔案並不為 null

ProcessInstance instance = new ProcessInstance(processDefinition);
// 建立處理流程檔實例

assertEquals(
"Instance is in start state",
instance.getRootToken().getNode().getName(),
"start");
// 測試現在正處於 start 點

assertNull(
"Message variable should not exist yet",
instance.getContextInstance().getVariable("message"));
// 測試 start 點的 message 為 null

instance.signal();
// 呼叫 signal() 表示此點處理完成, 將跳至下一點
// 由於上面設定了 ActionHandler, 將會設定 message 為 "Going to the first state!"

assertEquals(
"Instance is in first state",
instance.getRootToken().getNode().getName(),
"first");
// 測試現在正處於 first 點

assertEquals(
"Message variable contains message",
instance.getContextInstance().getVariable("message"),
"Going to the first state!");
// 由於已經觸發 MessageActionHandler,
// 測試此點 message property 為 "Going to the first state!"

instance.signal();
// 呼叫 signal() 表示此點處理完成, 將跳至下一點
// 由於上面設定了 ActionHandler, 將會設定 message 為 "About to finish!"

assertEquals(
"Instance is in end state",
instance.getRootToken().getNode().getName(),
"end");
// 測試現在正處於 end 點

assertTrue("Instance has ended", instance.hasEnded());
// 測試現在是最後終點

assertEquals(
"Message variable is changed",
instance.getContextInstance().getVariable("message"),
"About to finish!");
// 由於已經觸發 MessageActionHandler,
// 測試此點 message property 為 "About to finish!"

}
}
/*------------------ SimpleProcessTest.java -------------------*/

點選 SimpleProcessTest.java -> Run As -> JUnit Test
如下所示即測試成功


Console 輸出為：
00:33:44,597 [main] INFO JbpmConfiguration : using jbpm configuration resource ’jbpm.cfg.xml’
00:33:44,644 [main] DEBUG JbpmConfiguration : loading defaults in jbpm configuration
00:33:45,269 [main] DEBUG ObjectFactoryImpl : adding object info ’default.jbpm.context’
00:33:45,269 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.hibernate.cfg.xml’
00:33:45,269 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.business.calendar’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.default.modules’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.converter’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.action.types’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.node.types’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.parsers’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’resource.varmapping’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’jbpm.msg.wait.timout’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’jbpm.byte.block.size’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’mail.smtp.host’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’jbpm.task.instance.factory’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’jbpm.variable.resolver’
00:33:45,285 [main] DEBUG ObjectFactoryImpl : adding object info ’jbpm.mail.address.resolver’
00:33:45,285 [main] DEBUG JbpmConfiguration : loading specific configuration...
00:33:45,753 [main] DEBUG JpdlParser$JpdlEntityResolver : resolving schema reference publicId(null) systemId(http://jbpm.org/jpdl-3.1.xsd)
00:33:45,753 [main] DEBUG JpdlParser$JpdlEntityResolver : providing input source to local ’jpdl-3.1.xsd’ resource
00:33:46,019 [main] WARN JpdlXmlReader : process xml warning: warning: no swimlane or assignment specified for task ’




’
00:33:46,081 [main] DEBUG GraphElement : event ’process-start’ on ’ProcessDefinition(simple)’ for ’Token(/)’
00:33:46,081 [main] DEBUG GraphElement : event ’before-signal’ on ’StartState(start)’ for ’Token(/)’
00:33:46,081 [main] DEBUG GraphElement : event ’node-leave’ on ’StartState(start)’ for ’Token(/)’
00:33:46,081 [main] DEBUG GraphElement : event ’transition’ on ’Transition(to_state)’ for ’Token(/)’
00:33:46,081 [main] DEBUG GraphElement : executing action ’action[action]’
00:33:46,113 [main] DEBUG VariableContainer : create variable ’message’ in ’TokenVariableMapc4aad3’ with value ’Going to the first state!’
00:33:46,159 [main] DEBUG Converters : adding converter ’D’, ’org.jbpm.context.exe.converter.DoubleToStringConverter’
00:33:46,159 [main] DEBUG Converters : adding converter ’C’, ’org.jbpm.context.exe.converter.CharacterToStringConverter’
00:33:46,159 [main] DEBUG Converters : adding converter ’B’, ’org.jbpm.context.exe.converter.BooleanToStringConverter’
00:33:46,159 [main] DEBUG Converters : adding converter ’Y’, ’org.jbpm.context.exe.converter.BytesToByteArrayConverter’
00:33:46,159 [main] DEBUG Converters : adding converter ’A’, ’org.jbpm.context.exe.converter.DateToLongConverter’
00:33:46,159 [main] DEBUG Converters : adding converter ’R’, ’org.jbpm.context.exe.converter.SerializableToByteArrayConverter’
00:33:46,175 [main] DEBUG Converters : adding converter ’I’, ’org.jbpm.context.exe.converter.IntegerToLongConverter’
00:33:46,175 [main] DEBUG Converters : adding converter ’H’, ’org.jbpm.context.exe.converter.ShortToLongConverter’
00:33:46,175 [main] DEBUG Converters : adding converter ’G’, ’org.jbpm.context.exe.converter.FloatToDoubleConverter’
00:33:46,191 [main] DEBUG Converters : adding converter ’F’, ’org.jbpm.context.exe.converter.FloatToStringConverter’
00:33:46,191 [main] DEBUG Converters : adding converter ’E’, ’org.jbpm.context.exe.converter.ByteToLongConverter’
00:33:46,206 [main] DEBUG GraphElement : event ’node-enter’ on ’State(first)’ for ’Token(/)’
00:33:46,206 [main] DEBUG GraphElement : event ’after-signal’ on ’StartState(start)’ for ’Token(/)’
00:33:46,206 [main] DEBUG GraphElement : event ’before-signal’ on ’State(first)’ for ’Token(/)’
00:33:46,206 [main] DEBUG GraphElement : event ’node-leave’ on ’State(first)’ for ’Token(/)’
00:33:46,222 [main] DEBUG GraphElement : event ’transition’ on ’Transition(to_end)’ for ’Token(/)’
00:33:46,222 [main] DEBUG GraphElement : executing action ’action[action]’
00:33:46,222 [main] DEBUG VariableContainer : update variable ’message’ in ’TokenVariableMapc4aad3’ to value ’About to finish!’
00:33:46,222 [main] DEBUG GraphElement : event ’node-enter’ on ’EndState(end)’ for ’Token(/)’
00:33:46,222 [main] DEBUG GraphElement : event ’process-end’ on ’ProcessDefinition(simple)’ for ’Token(/)’
00:33:46,222 [main] DEBUG GraphElement : event ’after-signal’ on ’State(first)’ for ’Token(/)’

如下圖所示：


這裡只是簡單的介紹如何開發 workflow system,
並沒有實作用戶介面, 可集成至 JSP, JSF 或 Tapestry 實作.

如果需要 embed 到其他的系統, 可參考官方文檔：
http://docs.jboss.com/jbpm/v3/userguide/deployment.html

由於本人亦使用過 OpenWFE [Sourceforge workflow engine 熱門項目]
OpenWFE 功能比較強, 文檔亦很多, 也比較複雜.
但 JBoss jBPM 有 JBossIDE 支持, 感覺上比較容易開發.
總結是現在沒有一套 workflow engine 能滿足用戶的所有需求.

OpwnWFE 官方網頁：
http://www.openwfe.org,

JBoss jBPM 用戶手冊：
http://docs.jboss.com/jbpm/v3/userguide/

JBoss jBPM 官方文檔：
http://www.jboss.com/products/jbpm/docs

JBoss jBPM wiki：
http://wiki.jboss.org/wiki/Wiki.jsp?page=JbpmWiki

workflow pattern：
http://is.tm.tue.nl/research/patterns/