Is it good practice to make multiple classes Serializable?

Question

I was wondering about how to serialize nested classes properly.
My problem is that there is one class that has a list of data that I need to serialize. The data though, is an object of many other classes. For example if Test1 is my data class, it has Test1a and others.

The error that I get if I don't write "implements Serializable" is that it is "java.io.NotSerializableException".

Should I just "implement Serializable" to all my classes then?

public class Test1 implements Serializable {
     public void save() {
         //some code to save 
     }
     public void load() {
         //some code to load
     }
     public class Test1a {   
          //something related
     }
}

Answer 1

Yes. If you wan't to serialize a class, all the classes that it is dependent on should also be Serializable if you want to serialize them. If you don't wish to Serialize a member of a class, mark it as transient. When you mark something as transient, it will not be serialized. This means that when you deserialze an Object and it has a transient member, that transient member will get a default value.