Like C++, Java also supports copy constructors. But unlike C++, Java doesn't create a default copy constructor unless you write it yourself.

The following is an example Java program that demonstrates the simple use of the copy constructor.

In Java, a copy constructor is a special type of constructor that allows an object to be copied into another object of the same class. A copy constructor is used to create a new object that is a copy of an existing object, allowing the programmer to duplicate the object's state and behavior.

The copy constructor takes an object of the same class as a parameter and creates a new object with the same values as the passed object. The constructor can be defined with the same name as the class, followed by the parameter of the same class type.

For example, suppose we have a class called Person with a copy constructor defined as follows: 

public class Person {
    private String name;
    private int age;
    
    // copy constructor
    public Person(Person p) {
        this.name = p.name;
        this.age = p.age;
    }
    
    // other constructors and methods...
}

In the above example, the copy constructor takes a Person object as a parameter and initializes the new object with the same values as the passed object.

Copy constructors can be useful when working with complex objects that need to be duplicated without modifying the original object. However, it's important to note that the copy constructor is not automatically generated by Java, so it must be defined explicitly in the code.