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GWT RCP-序列化异常

gwt jakarta-ee

GWT RCP-序列化异常,gwt,jakarta-ee,eclipselink,gwt-rpc,Gwt,Jakarta Ee,Eclipselink,Gwt Rpc,从头开始一个新项目，转换成JPA，我的持久性提供者是EclipseLink，添加了必要的库（EclipseLink.jar、EclipseLink.jar、javax.persistence、mysql-connector-java-5.1）。测试了连接，ping正常。然后创建了一个新包new>JPA>Entities from Tables>Selected all Entities and Key generator>Identity GestorIpca.java

从头开始一个新项目，转换成JPA，我的持久性提供者是EclipseLink，添加了必要的库（EclipseLink.jar、EclipseLink.jar、javax.persistence、mysql-connector-java-5.1）。测试了连接，ping正常。然后创建了一个新包new>JPA>Entities from Tables>Selected all Entities and Key generator>Identity

GestorIpca.java

            GestorIpcaService.util.getInstance().getLista(new AsyncCallback<ArrayList<Docente>>() {

                @Override
                public void onFailure(Throwable caught) {
                    Window.alert("Erro na Ligacao efectuada");
                    caught.getStackTrace();
                }

                @Override
                public void onSuccess(ArrayList<Docente> result) {
                    Window.alert("Ligacao efectuada com sucesso:" + result.size());
                }
            });
Mypersistence.xml是自动创建的。放在META-INF中

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
    <persistence-unit name="GestorIpca">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

    <class>com.GestorIpca.shared.Ano</class>
    <class>com.GestorIpca.shared.Categoria</class>
    <class>com.GestorIpca.shared.Curso</class>
    <class>com.GestorIpca.shared.Disciplina</class>
    <class>com.GestorIpca.shared.Disponibilidade</class>
    <class>com.GestorIpca.shared.Docente</class>
    <class>com.GestorIpca.shared.Sala</class>
    <class>com.GestorIpca.shared.Semestre</class>
    <class>com.GestorIpca.shared.TipoCurso</class>
    <class>com.GestorIpca.shared.Turma</class>
    <class>com.GestorIpca.shared.User</class>
        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/timetable"/>
            <property name="javax.persistence.jdbc.user" value="root"/>
            <property name="javax.persistence.jdbc.password" value="k771u3"/>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
        </properties>
    </persistence-unit>
</persistence>
注意：我在com.GestorIpca.shared包中更改了从表生成的所有类

public class Ano implements Serializable
到

public class Ano implements IsSerializable
还更改了myGestorIpca.gwt.xml，并在末尾添加了这一行

<extend-configuration-property name="rpc.blacklist" value="com.google.gwt.user.client.ui.*Collection"/>
<extend-configuration-property name="rpc.blacklist" value="-.*List"/>
<extend-configuration-property name="rpc.blacklist" value="-.*Map"/>
<extend-configuration-property name="rpc.blacklist" value="-.*Collection"/>
<extend-configuration-property name="rpc.blacklist" value="+java.util.HashMap"/>
<extend-configuration-property name="rpc.blacklist" value="+java.util.LinkedHashMap"/>
<extend-configuration-property name="rpc.blacklist" value="+java.util.ArrayList"/>
我遗漏了什么？

如果不知道您的实体是什么样子，我会从异常中猜测原因可能是您的实体如何通过持久性提供程序得到增强：

这对GWT RPC意味着，当对象准备好通过线路传输时，它实际上不是编译器认为要传输的同一个对象，因此在尝试反序列化时，GWT RPC机制不再知道类型是什么，并拒绝反序列化它

引自：

这篇文章还建议如何创建DTO来解决这个问题。

我取决于实体是如何定义的。可能存在GWT RPC不喜欢的连接。在这种情况下，我建议创建DTO或实现RequestFactory，我知道这是一个非常古老的问题，但今晚我遇到了这个问题

GWT序列化似乎不喜欢java.util.Set。我几乎感觉它混淆了java.util.Set和org.eclipse.persistence.indirection.IndirectSet

一旦我将Set切换到ArrayList，错误就消失了。

所以我需要为每个类创建一个DTO？哦，天哪。这篇文章发表于2009年。两年后，他们仍然没有解决这个问题？是的，他们解决了：他们建造了一个工厂。 
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
    <persistence-unit name="GestorIpca">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

    <class>com.GestorIpca.shared.Ano</class>
    <class>com.GestorIpca.shared.Categoria</class>
    <class>com.GestorIpca.shared.Curso</class>
    <class>com.GestorIpca.shared.Disciplina</class>
    <class>com.GestorIpca.shared.Disponibilidade</class>
    <class>com.GestorIpca.shared.Docente</class>
    <class>com.GestorIpca.shared.Sala</class>
    <class>com.GestorIpca.shared.Semestre</class>
    <class>com.GestorIpca.shared.TipoCurso</class>
    <class>com.GestorIpca.shared.Turma</class>
    <class>com.GestorIpca.shared.User</class>
        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/timetable"/>
            <property name="javax.persistence.jdbc.user" value="root"/>
            <property name="javax.persistence.jdbc.password" value="k771u3"/>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
        </properties>
    </persistence-unit>
</persistence>

[EL Info]: 2011-05-09 10:03:08.78--ServerSession(8068087)--EclipseLink, version: Eclipse Persistence Services - 2.2.0.v20110202-r8913
[EL Info]: 2011-05-09 10:03:09.297--ServerSession(8068087)--file:/C:/Users/Martinho/WorkSpace/GestorIpca/war/WEB-INF/classes/_GestorIpca login successful
Starting Jetty on port 8888
   [WARN] Exception while dispatching incoming RPC call
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$8.write(ServerSerializationStreamWriter.java:152)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:534)
    at com.google.gwt.user.server.rpc.RPC.encodeResponse(RPC.java:616)
    at com.google.gwt.user.server.rpc.RPC.encodeResponseForSuccess(RPC.java:474)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:571)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:324)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
    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.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeWithCustomSerializer(ServerSerializationStreamWriter.java:746)
    ... 30 more
Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'org.eclipse.persistence.indirection.IndirectSet' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = {IndirectSet: not instantiated}
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:614)
    at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:152)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:534)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeClass(ServerSerializationStreamWriter.java:704)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:734)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:616)
    at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
    at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$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)
    ... 35 more
[ERROR] 500 - POST /gestoripca/greet (127.0.0.1) 57 bytes
   Request headers
      Host: 127.0.0.1:8888
      Connection: keep-alive
      Referer: http://127.0.0.1:8888/GestorIpca.html?gwt.codesvr=127.0.0.1:9997
      Content-Length: 132
      Origin: http://127.0.0.1:8888
      X-GWT-Module-Base: http://127.0.0.1:8888/gestoripca/
      X-GWT-Permutation: HostedMode
      User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.30 (KHTML, like Gecko) Chrome/12.0.742.30 Safari/534.30
      Content-Type: text/x-gwt-rpc; charset=UTF-8
      Accept: */*
      Accept-Encoding: gzip,deflate,sdch
      Accept-Language: pt-PT,pt;q=0.8,en-US;q=0.6,en;q=0.4
      Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
   Response headers
      Content-Type: text/plain    

public class Ano implements Serializable 

public class Ano implements IsSerializable    

<extend-configuration-property name="rpc.blacklist" value="com.google.gwt.user.client.ui.*Collection"/>
<extend-configuration-property name="rpc.blacklist" value="-.*List"/>
<extend-configuration-property name="rpc.blacklist" value="-.*Map"/>
<extend-configuration-property name="rpc.blacklist" value="-.*Collection"/>
<extend-configuration-property name="rpc.blacklist" value="+java.util.HashMap"/>
<extend-configuration-property name="rpc.blacklist" value="+java.util.LinkedHashMap"/>
<extend-configuration-property name="rpc.blacklist" value="+java.util.ArrayList"/>