Overload and hide methods in Java

Question

i have an abstract class BaseClass with a public insert() method:

public abstract class BaseClass {

 public void insert(Object object) {
  // Do so         


        

Answer 1

This sounds like a badly designed hierarchy -

If no default exists and the user shouldn't call the method at all you can mark the method as @Deprecated and throw an UnsupportedOperationException as other posters have noted. However - this is really only a runtime check. @Deprecated only throws a compiler warning and most IDEs mark it in some way, but there's no compile time prevention of this. It also really sucks because it's possible to get the child class as a parent class reference and call the method on it with no warning that it's "bad" at all. In the example below, there won't be any indication until runtime that anything's wrong.

Example:

// Abstract base builder class
public abstract class BaseClassBuilder {
    public final doBuild() {
        BaseClass base = getBase();
        for (Object obj : getObjects() {
            base.insert(obj);
        }
    }
    protected abstract BaseClass getBase();
    protected abstract Object[] getObjects();
}

// implementation using SampleClass
public class SampleClassBuilder extends BaseClassBuilder {

    @Override
    protected BaseClass getBase() {
        return new SampleClass();
    }

    @Override
    protected Object[] getObjects() {
        Object[] obj = new Object[12];
        // ...
        return obj;
    }
}

However, if a sensible default exists, you could mark the inherited method as final and provide the default value inside of it. This handles both the bad hierarchy, and it prevents the "unforseen circumstances" of the above example.

Example:

public abstract class BaseClass { 
    public void insert(Object object) {
        // ...
    }
}

public class SampleClass extends BaseClass {

    public static final Long DEFAULT_PARAM = 0L;

    public final void insert(Object object) {
        this.insert(object, DEFAULT_PARAM);
    }

    public void insert(Object object, Long param) {
        // ...
    }
}