JavaCDI:为什么我的瞬态字段被序列化?
使用CDI(Weld),我为一个不可序列化的类实现了一个生产者方法。如果生产者被序列化并且字段NonSerializableObject不存在,我将重新初始化一个NonSerializableObject:
@SessionScoped
public class NonSerializableObjectProducer implements Serializable {
/** UUID */
private static final long serialVersionUID = -436472364723647647367L;
/** my transient non serializbale object */
private transient NonSerializableObject nonSerializableObject;
@SessionScoped
@Produces
protected NonSerializableObject produceNonSerializableObject() {
if (nonSerializableObject == null) {
// reinitialize object and set it
// nonSerializableObject = ...
}
return nonSerializableObject;
}
我注入了一个非序列化对象,如:
@SessionScoped
public class UseSerializableObject implements Serializable {
private static final long serialVersionUID = 62378785678643784689L;
@Inject
private transient NonSerializableObject nonSerializableObject;
public void doSomething() {
nonSerializableObject.go();
}
}
当我的应用服务器(Tomcat 7)重新部署时,会发生以下异常:
Sep 22, 2014 4:41:58 PM org.apache.catalina.session.StandardSession writeObject
WARNING: Cannot serialize session attribute WELD_S#5 for session 4694BB90FF1BBD8
java.io.NotSerializableException: com.MemberOfNonSerializableObject
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1181)
因此,非序列化对象的成员变量被序列化。为什么?我宣布一切都是暂时的
# 1 楼答案
你的方法是:
生成不可序列化的
@SessionScoped
对象。所有@RequestScoped、@SessionScoped和@ApplicationScoped bean都必须是可序列化的因此,如果您将@SessionScoped从producer方法中删除,它将起作用