Google app engine Google应用程序引擎GWT日期序列化

当序列化（java.util）对象中的日期字段可用时，我遇到以下错误。我的GWT版本是2.1.1，APP engine SDk是1.4.2

有人知道这个问题吗

com.google.gwt.user.client.rpc.SerializationException: java.lang.reflect.InvocationTargetException
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeWithCustomSerializer(ServerSerializationStreamWriter.java:764)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:727)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:616)
    at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:152)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:534)
    at com.google.gwt.user.server.rpc.RPC.encodeResponse(RPC.java:609)
    at com.google.gwt.user.server.rpc.RPC.encodeResponseForSuccess(RPC.java:467)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:564)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:207)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:243)
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:58)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:70)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:351)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:100)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeWithCustomSerializer(ServerSerializationStreamWriter.java:746)
    ... 38 more
Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'org.datanucleus.sco.simple.Date' 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 = Fri Mar 25 06:30:00 UTC 2011
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:614)
    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:152)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:534)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeClass(ServerSerializationStreamWriter.java:704)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:734)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:616)
    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:38)
    ... 43 more

---

谢谢。

从堆栈跟踪的这一行判断：

Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'org.datanucleus.sco.simple.Date' 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 = Fri Mar 25 06:30:00 UTC 2011

---

听起来您的IDE导入了一个版本的

Date

，而不是您期望的版本（即

java.util.Date

）。这种事经常发生在我身上。只需更改错误的导入。

从堆栈跟踪的这行判断：

Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'org.datanucleus.sco.simple.Date' 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 = Fri Mar 25 06:30:00 UTC 2011

---

听起来您的IDE导入了一个版本的

Date

，而不是您期望的版本（即

java.util.Date

）。这种事经常发生在我身上。只需更改错误的导入。

在将JDO对象发送回客户端之前，您需要分离服务器上的JDO对象

PersistenceManager pm = PMF.getPM();
pm.makePersistent(myObject);
return pm.detachCopy(myObject);

---

在将JDO对象发送回客户端之前，需要在服务器上分离它

PersistenceManager pm = PMF.getPM();
pm.makePersistent(myObject);
return pm.detachCopy(myObject);

---

问题是JDO返回的日期对象包含许多不必要的数据。我是这样修理的：

public Date getDate() {
    if(date!= null){
        long timeStamp = date.getTime();        
        return new Date(timeStamp);
    }           
    return null;
}

---

谢谢

问题是JDO返回的日期对象包含了许多不必要的数据。我是这样修理的：

public Date getDate() {
    if(date!= null){
        long timeStamp = date.getTime();        
        return new Date(timeStamp);
    }           
    return null;
}

---

谢谢你

哇，真是妙不可言！我真的很感激这个提示-节省了我很多时间！哇，真是妙计！我真的很感激这个提示-节省了我很多时间！我认为这里发生的神奇之处在于，您将

org.datanucleus.sco.simple.Date

的实例转换为

java.util.Date

。客户端不知道datanucleus库，但知道标准Java类。我认为这里发生的神奇之处在于，您将

org.datanucleus.sco.simple.Date

的实例转换为

Java.util.Date

。客户端不知道datanucleaus库，但知道标准Java类。