如何计算Java中某人的年龄？

JDK 8使这个变得轻松而优雅：

public class AgeCalculator {    public static int calculateAge(LocalDate birthDate, LocalDate currentDate) {        if ((birthDate != null) && (currentDate != null)) { return Period.between(birthDate, currentDate).getYears();        } else { return 0;        }    }}

一个JUnit测试以证明其用法：

public class AgeCalculatorTest {    @Test    public void testCalculateAge_Success() {        // setup        LocalDate birthDate = LocalDate.of(1961, 5, 17);        // exercise        int actual = AgeCalculator.calculateAge(birthDate, LocalDate.of(2016, 7, 12));        // assert        Assert.assertEquals(55, actual);    }}

现在每个人都应该使用JDK 8。所有较早的版本都已终止其支持寿命。