好像源代码功能有点问题.

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 *
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 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
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 * License along with this software; if not, write to the Free
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 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
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package org.jbpm.jpdl.patterns;

import junit.framework.*;

import org.jbpm.graph.def.*;
import org.jbpm.graph.exe.*;

/**
 * http://is.tm.tue.nl/research/patterns/download/swf/pat_5.swf
 *
 * <p>in jbpm every node has an implicit merge in front of it.
 * so it's not necessary to use the merge node.  in fact, i can
 * not think of a situation where implicit merge nodeMap are not
 * sufficient.  for the sake of workflow patterns, we leave if in.
 * jbpm supports merging of both alternative paths of execution
 * and concurrent paths of execution.
 * </p>
 *
 * <p>first the merge node is demonstrated exactly as in the pattern.
 * then the implicit variant is demonstrated, then the merging of
 * concurrent paths is demonstrated.
 * </p>
 */
public class Wfp05SimpleMergeTest extends TestCase {

  private static ProcessDefinition simpleMergeProcessDefinition = createSimpleMergeProcessDefinition();
 
  public static ProcessDefinition createSimpleMergeProcessDefinition() {
    ProcessDefinition pd = new ProcessDefinition(
      new String[]{"start-state start",
                   "state a",
                   "state b",
                   "merge xor",
                   "state c"},
      new String[]{"start --to a--> a",
                   "start --to b--> b",
                   "a --> xor",
                   "b --> xor",
                   "xor --> c"});
    return pd;
  }

  public void testSimpleMergeScenario1() {
    ProcessDefinition pd = simpleMergeProcessDefinition;
    ProcessInstance pi = new ProcessInstance( pd );
    pi.signal("to a");
    Token root = pi.getRootToken();
    assertSame( pd.getNode("a"), root.getNode() );
    root.signal();
    assertSame( pd.getNode("c"), root.getNode() );
  }

  public void testSimpleMergeScenario2() {
    ProcessDefinition pd = simpleMergeProcessDefinition;
    ProcessInstance pi = new ProcessInstance( pd );
    pi.signal("to b");
    Token root = pi.getRootToken();
    assertSame( pd.getNode("b"), root.getNode() );
    root.signal();
    assertSame( pd.getNode("c"), root.getNode() );
  }
 
  private static ProcessDefinition implicitMergeProcessDefinition = createImplicitMergeProcessDefinition();
 
  public static ProcessDefinition createImplicitMergeProcessDefinition() {
    ProcessDefinition pd = new ProcessDefinition(
      new String[]{"start-state start",
                   "state a",
                   "state b",
                   "state c"},
      new String[]{"start --to a--> a",
                   "start --to b--> b",
                   "a --> c",
                   "b --> c"});
    return pd;
  }

  public void testImplicitMergeScenario1() {
    ProcessDefinition pd = implicitMergeProcessDefinition;
    ProcessInstance pi = new ProcessInstance( implicitMergeProcessDefinition );
    pi.signal("to a");
    Token root = pi.getRootToken();
    assertSame( pd.getNode("a"), root.getNode() );
    root.signal();
    assertSame( pd.getNode("c"), root.getNode() );
  }
 
  public void testImplicitMergeScenario2() {
    ProcessDefinition pd = implicitMergeProcessDefinition;
    ProcessInstance pi = new ProcessInstance( implicitMergeProcessDefinition );
    pi.signal("to b");
    Token root = pi.getRootToken();
    assertSame( pd.getNode("b"), root.getNode() );
    root.signal();
    assertSame( pd.getNode("c"), root.getNode() );
  }
 
}

createSimpleMergeProcessDefinition()

创建如下流程定义文件



testSimpleMergeScenario1()

节点执行顺序
   
    start --> a --> xor --> c

testSimpleMergeScenario2()
 
    start --> b --> xor --> c

createImplicitMergeProcessDefinition()

创建如下流程定义文件



testImplicitMergeScenario1()
节点执行顺序

  start --> a --> c

testImplicitMergeScenario2()
节点执行顺序

  start --> b --> c



以上是对基本控制流程的一些说明, 本人水平有限, 难免有不当之处. 欢迎批评指正.