【发布时间】：2012-01-05 11:29:10
【问题描述】：
我正在开发一个互连 GWT 和 Hibernate 的应用程序。从 GWT 服务器端，我有以下代码：
@Override
public List<AlarmDTO> getAlarms() throws Exception{
return deviceService.getAlarms();
}
在 Hibernate 方面，有一个 Alarm 类：
public List<AlarmDTO> getAlarms() {
@SuppressWarnings("unchecked")
List<Alarm> alarms = new ArrayList<Alarm>(DatabaseManager.createQuery("from Alarm"));
List<AlarmDTO> alarmsDTOs = new ArrayList<AlarmDTO>(alarms != null ? alarms.size() : 0);
if (alarms != null) {
for (Alarm alarm : alarms) {
String date = format.format(alarm.gettDate());
alarmsDTOs.add(new AlarmDTO(alarm.getiAlarmId(),alarm.getsDescription(),alarm.getsCause(),date,alarm.iSetPointId,alarm.getiDeviceId()));
}
}
return alarmsDTOs;
}
它返回一个 AlarmDTO 对象列表。这种类型的对象是数据传输对象。它的代码是：
public class AlarmDTO implements Serializable{
private static final long serialVersionUID = 1L;
private int iAlarmId;
private String sDescription;
private String sCause;
private String sDate;
private int iSetPointId;
private int iDeviceId;
public AlarmDTO(){}
public AlarmDTO(int iAlarmId,String sDescription,String sCause,String sDate,int iSetPointId,int iDeviceId){
this.iAlarmId = iAlarmId;
this.sDescription = sDescription;
this.sCause = sCause;
this.sDate = sDate;
this.iSetPointId = iSetPointId;
this.iDeviceId = iDeviceId;
}
}
但是，当我运行应用程序时，它会抛出异常 com.google.gwt.user.client.rpc.SerializationException:
Exception while dispatching incoming RPC call
com.google.gwt.user.client.rpc.SerializationException: Type 'com.cartif.dtos.EnergyDTO' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = com.cartif.dtos.EnergyDTO@16b4be5
at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:615)
at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
at com.google.gwt.user.client.rpc.core.java.util.Collection_CustomFieldSerializerBase.serialize(Collection_CustomFieldSerializerBase.java:45)
at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serialize(ArrayList_CustomFieldSerializer.java:40)
at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serializeInstance(ArrayList_CustomFieldSerializer.java:50)
at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serializeInstance(ArrayList_CustomFieldSerializer.java:28)
at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:736)
at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:617)
at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:153)
at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:535)
at com.google.gwt.user.server.rpc.RPC.encodeResponse(RPC.java:616)
at com.google.gwt.user.server.rpc.RPC.encodeResponseForSuccess(RPC.java:474)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:571)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:206)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:320)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:842)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:648)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:450)
我对其他对象遵循相同的策略并且它有效。我不知道为什么它现在不运行。有人可以帮我吗？
谢谢！
【问题讨论】：
-
您还有用于 AlarmDTO 的 getter/setter 吗？尝试使用干净的构建。
-
你能分享更多关于这个异常的信息吗 - 它是在发送时发生在服务器上，还是在尝试读取时发生在客户端上？此外，AlarmDTO 类是否在可以转换为客户端代码的包中（与其他工作 DTO 相同的包）？
-
我添加了类似于 AlarmDTO 的 EnergyDTO 异常
标签： hibernate gwt serialization dto