我正在使用GSON。当我启动tomcat时，它会给我错误。我的部分代码：
@ManagedBean(name = "kpilist")
@ViewScoped
public class KPIListController implements Serializable {
public List<KPI> getKPI() {
KPIDAO kpiDAO = new KPIDAO();
List<KPI> kpiList = new ArrayList<KPI>();
Gson gson = new Gson();
try {
kpiList = kpiDAO.getKPI(selectedKPIType);
json = gson.toJson(kpiList) ;
Logger.getLogger(KPIListController.class.getName()).warning("The KPI JSON" + json);
} catch (SQLException ex) {
ex.printStackTrace();
return null;
}
return kpiList;
}
WARNING: Cannot serialize session attribute com.sun.faces.renderkit.ServerSideStateHelper.LogicalViewMap for session 41AC6C7AB4B0869A29778EA4155BFCA1
java.io.NotSerializableException: com.google.gson.Gson
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1180)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.HashMap.writeObject(HashMap.java:1014)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:962)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1362)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1170)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.HashMap.writeObject(HashMap.java:1014)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:962)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1362)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1170)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.HashMap.writeObject(HashMap.java:1014)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:962)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.HashMap.writeObject(HashMap.java:1014)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:962)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at org.apache.catalina.session.StandardSession.writeObject(StandardSession.java:1692)
at org.apache.catalina.session.StandardSession.writeObjectData(StandardSession.java:1092)
at org.apache.catalina.session.StandardManager.doUnload(StandardManager.java:411)
at org.apache.catalina.session.StandardManager.unload(StandardManager.java:353)
at org.apache.catalina.session.StandardManager.stopInternal(StandardManager.java:497)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:232)
at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5449)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:232)
at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1540)
at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1530)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
我在使用GSON时犯了什么错误吗？
在您的代码中，我看不到它，但看起来有一个成员变量包含一个Gson，可能是间接的（它甚至可以是一个捕获它的匿名类实例）。AFAIK，异常表明Gson不是Serializable，"这没关系，因为你可能无论如何都不想存储它。
您可以尝试使用；瞬态"；关键词：
transient Gson gson = new Gson();
这将忽略"；gson"；在序列化期间。您可以在此处阅读更多信息：https://www.baeldung.com/java-transient-keyword.
谨致问候。