Java – use “this” in another constructor

Suppose you have a class with this constructor:

public SomeObj(int x,int y) {
    this.x = x;
    this.y = y;
}

Everything is fine But now if you want to clone an object, I want the constructor to accept an argument with an object of that type, so you can copy all (necessary) fields in the constructor

public SomeObj(SomeObj objectToClone) { ... }

But now which two ways are better? What are the advantages and disadvantages (performance (bytecode), readability...)?

// 1
public SomeObj(SomeObj objectToClone) {
    this.x = objectToClone.x;
    this.y = objectToClone.y;
}

// 2
public SomeObj(SomeObj objectToClone) {
    this(objectToClone.x,objectToClone.y);
}

Solution

Personally, I'll go with the latter

Where possible, I try to make a constructor have a "real" body and delegate it to all other builders This is not always possible - in particular, different constructors may need to be delegated to different super constructors - but it's nice to know that there's a place for additional initialization, logging, breakpoints, and so on