在play框架2.1中使用xstream遇到了CannotResolveClassException

Question

当我在Play 2中使用xstream时，我得到了例外

    play.api.Application$$anon$1: Execution   
    exceptin[[CannotResolveClassException: models.xmldata.TestData]]
    at play.api.Application$class.handleError(Application.scala:289)
    at play.api.DefaultApplication.handleError(Application.scala:383)
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anon$2$$anonfun$ha
    ndle$1.apply(PlayDefaultUpstreamHandler.scala:132)
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anon$2$$anonfun$ha
    ndle$1.apply(PlayDefaultUpstreamHandler.scala:128)
    at play.api.libs.concurrent.PlayPromise$$anonfun$extend1$1.apply(Promise
    .scala:113)
    at play.api.libs.concurrent.PlayPromise$$anonfun$extend1$1.apply(Promise
   .scala:113)
   com.thoughtworks.xstream.mapper.CannotResolveClassException:     
   models.xmldata.Test
   Data
    at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper
   .java:56)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper
   .java:30)
    at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicP
    roxyMapper.java:55)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper
   .java:30)
    at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(Packa
    geAliasingMapper.java:88)
    at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper
    .java:30)

我的开发环境：

播放2.1.0， JDK-1.7，

我使用的罐子：

xmlpull-1.1.3.1.jar xpp3_min-1.1.4c.jar， XStream的-1.4.2.jar

这是我的代码，

    public void test(){
        String ss = "<TestData><vcEmployeeID>1234567</vcEmployeeID></TestData>";
        try {
             TestData xml2Bean = XML2Bean(ss, TestData.class);
        } catch (IOException e) {
             e.printStackTrace();
        }
     }

    public static <T> T XML2Bean(String xmlInfo, Class<T> clazz) throws IOException {

       XStream xstream = new XStream(new DomDriver());

       xstream.processAnnotations(clazz);

       return (T) xstream.fromXML(xmlInfo);
    }

TestData.java

    @XStreamAlias("TestData")
    public class TestData implements Serializable {

      private static final long serialVersionUID = -7740677280125570535L;

      @XStreamAlias("vcEmployeeID")
      private String vcEmployeeID;

      public String getVcEmployeeID() {
         return vcEmployeeID;
      }

      public void setVcEmployeeID(String vcEmployeeID) {
         this.vcEmployeeID = vcEmployeeID;
      }

   }

＆＃34;为什么呢？如何解决？＆＃34;知道为什么会这样吗？