外部不可变和内部可变类的示例

class MyClass {    

    private final int value;

    private int halfValue = Integer.MAX_VALUE;
/*from 时代Java公众号*/

    public MyClass(int value) {

        this.value = value;

    }       


    public int getValue() {

        return value;

    }


    public int getHalfValue() {

        // Compute half value if it is not already computed

        if (this.halfValue == Integer.MAX_VALUE) {/** from nowjava.com - 时  代  Java**/

            // Cache the half value for future use