public class Date {
    private Day d;
    private Month m;
    private Year y;

    public Date(int pMonth, int pDay, int pYear) {
        y = new Year(pYear);
        m = new Month(pMonth, y);
        d = new Day(pDay, m);
    }

    public void increment() {
        if (!d.increment()) {
            if (!m.increment()) {
                y.increment();
                m.setMonth(1, y);
            }
            d.setDay(1, m);
        }
    }

    public void printDate() {
        System.out.println(m.getMonth() + "/" + d.getDay() + "/" + y.getYear());
    }
    public String getDate(){
        return m.getMonth() + "/" + d.getDay() + "/" + y.getYear();
    }
}

import static org.junit.Assert.assertEquals;

import java.util.Arrays;
import java.util.Collection;

import nextdate.Date;

import org.junit.Test;
import org.junit.runner.JUnitCore;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

@RunWith(Parameterized.class)
public class DateTest {
    
    private static String expected;
    private static int target;
    
    /**
     * 构造函数
     * @param expected
     *            期望的测试结果，对应参数集中的第一个参数
     * @param target
     *            测试数据，对应参数集中的第二个参数
     */
    public DateTest(String expected, int target) {

        this.expected = expected;
        this.target = target;
    }
    
    @Parameters
    public  static Collection dates() {           //问题就在这个静态方法，里边调用外部类，去static
        Date date0 = new Date(6, 15, 2000);   //又不行，该怎么修改？？？
        Date date1 = new Date(2, 29, 2000);
        Date date2 = new Date(2, 28, 2001);
        Date date3 = new Date(3, 30, 2000);
        Date date4 = new Date(4, 30, 2000);
        date0.increment();
        date1.increment();
        date2.increment();
        date3.increment();
        date4.increment();

        return Arrays.asList(new Object[][] { 
                { "6/16/2000", date0.getDate()}, 
                { "3/1/2000",  date1.getDate() }, 
                { "2/29/2000", date2.getDate() }, 
                { "3/31/2000", date3.getDate() }, 
                { "5/1/2000",  date4.getDate()},
            
        });
    }

    @Test
    public void increment() {
        assertEquals(expected,target);
    }

    public static void main(String[] args) {
        JUnitCore.main(new String[] { "DateTest" });

    }
}