What is the right way to assign a data member to another data member of generic type-CodePudding

interface IBase {
    void doJob();
}

public class MyCache<T extends IBase> {
    private T t1;
    private T t2;
    public MyCache(T t1, T t2) {
        this.t1 = t1;
        this.t2 = t2;
    }

    @PostConstruct
    private void init() {
        t1.update();
        t2 = t1.clone(); // ERROR!
    }
}

As you see, I'm trying to develop a generic class. In the function init(), I assign the copy of t1 to t2. But it can't be compiled.

I'm not very good at Java. Can someone help me on this issue?

CodePudding user response：

Look at the contract public Object clone(), so to use this method in your class you shouild declare it and case Object to the T.

interface IBase extends Cloneable {

    void doJob();

    void update();
    
    Object clone();

}

public class MyCache<T extends IBase> {

    private T t1;
    private T t2;

    public MyCache(T t1, T t2) {
        this.t1 = t1;
        this.t2 = t2;
    }

    private void init() {
        t1.update();
        t2 = (T)t1.clone();
    }
}

P.S. This is working solution, but at this time an outdated. It's better to use a copy constructor instead.