Mido :
I am trying to pass an object from the server to the client using ObjectOutputStream .
DataObject class:
public class DataObject implements Serializable{
private byte dataType;
private Object data;
public DataObject(byte dataType, Serializable data) {
this.dataType = dataType;
this.data = data;
}
Player class
public class Player implements Serializable{
private int mana, health;
private List<Integer> hand, grave, deck, used;
private Effect healing, posioned, grievousWound, exhaust, resistance, power;
private Player enemy;
I sent it away with this code
os = new ObjectOutputStream(server.getOutputStream());
os.writeObject(new DataObject((byte) 8, this.player));
System.out.println(this.player);
// It has printed out exact object
And get it with
DataObject d = (DataObject) is.readObject()
System.out.println(d.getDataType());
System.out.println(d.getData());
System.out.println((Player)d.getData());
It has printed out
8
null
What is the problem I'm having?
I fixed Object to Serializable
private byte dataType;
private Serializable data;
os.writeObject(new DataObject((byte) 8,(Serializable)this.player));
Tom Hawtin - tackline :
The code shown is okay(ish). The bug lies somewhere else. To demonstrate this I have expanded the original code to make an MRE, other than not reproducing and containing unnecessary detail.
import java.io.*;
import java.util.*;
class DataObject implements Serializable{
private byte dataType;
private Object data;
public DataObject(byte dataType, Object data) {
this.dataType = dataType;
this.data = data;
}
public byte getDataType() { return dataType; }
public Object getData() { return data; }
}
class Effect implements Serializable { }
class Player implements Serializable {
private int mana, health;
private List<Integer> hand, grave, deck, used;
private Effect healing, posioned, grievousWound, exhaust, resistance, power;
private Player enemy;
}
class Code {
private final Player player = new Player();
public static void main(String[] args) throws Throwable {
new Code().go();
}
public void go() throws Throwable {
ByteArrayOutputStream out = new ByteArrayOutputStream();
try (ObjectOutputStream os = new ObjectOutputStream(out)) {
os.writeObject(new DataObject((byte) 8, this.player));
System.out.println(this.player);
}
ObjectInputStream is = new ObjectInputStream(
new ByteArrayInputStream(out.toByteArray())
);
DataObject d = (DataObject) is.readObject();
System.out.println(d.getDataType());
System.out.println(d.getData());
System.out.println((Player)d.getData());
}
}
This prints:
Player@4fca772d
8
Player@49097b5d
Player@49097b5d
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