different handles in public static final class variable

Question

I have clas that emulates enum behavior for java 1.4

public class PacketType {

    String Name ="9";

    public static final PacketType None = new PacketType("9");
    public static final PacketType StartOfOperation = new PacketType("1");

    PacketType (String Name ) {
        this.Name = Name;
    }

    public String toString() {
        return Name ;       
    }

    public static void main(String[] args) {
        PacketType p = PacketType.StartOfOperation;

        if (p == PacketType.StartOfOperation) {
            System.out.print("==");
        }

        if (p.equals(PacketType.StartOfOperation) ) {
            System.out.print("equals");
        }
    }
}

Now I need to know which value has variable p . Both , equals and == pass checking in the main function. But in case I have several threads in my application it does't pass this check. I have assigned the same static variable PacketType.StartOfOperation for all my PacketType variables. Debugger shows that I have the same value, but not the same variable handler (that is why it not pass equal and == ). I expect that it should have the same handle. Why it behaves so strange?

Answer 1

When you use == it returns true if both references point to same object.

if (p == PacketType.StartOfOperation)

Here both the references points to different objects, hence it will not execute. Try this

 PacketType p =PacketType.None;
 PacketType p1 =PacketType.None;   

    if (p == p1)
    {
    System.out.print("=="); //prints ==
    }

Since None is static, every reference points to same object and == will return true.