Java程序代码：判断英文周几，并使用JUnit进行语句覆盖测试

以下是使用Java编写的程序代码：

public class DayOfWeek {
    public static String getDayOfWeek(char uppercase, char lowercase) {
        String day = "";

        // 根据第一个大写字母判断周几
        switch (uppercase) {
            case 'M':
                day = "Monday";
                break;
            case 'T':
                day = "Tuesday";
                break;
            case 'W':
                day = "Wednesday";
                break;
            case 'F':
                day = "Friday";
                break;
            default:
                // 根据第二个小写字母判断周几
                switch (lowercase) {
                    case 'u':
                        day = "Sunday";
                        break;
                    case 'h':
                        day = "Thursday";
                        break;
                    case 'a':
                        day = "Saturday";
                        break;
                    default:
                        day = "Invalid input";
                }
        }

        return day;
    }
}

以下是使用JUnit框架编写的测试类：

import org.junit.Test;
import static org.junit.Assert.*;

public class DayOfWeekTest {
    @Test
    public void testMonday() {
        assertEquals("Monday", DayOfWeek.getDayOfWeek('M', 'a'));
    }

    @Test
    public void testTuesday() {
        assertEquals("Tuesday", DayOfWeek.getDayOfWeek('T', 'u'));
    }

    @Test
    public void testWednesday() {
        assertEquals("Wednesday", DayOfWeek.getDayOfWeek('W', 'e'));
    }

    @Test
    public void testFriday() {
        assertEquals("Friday", DayOfWeek.getDayOfWeek('F', 'r'));
    }

    @Test
    public void testSunday() {
        assertEquals("Sunday", DayOfWeek.getDayOfWeek('A', 'u'));
    }

    @Test
    public void testThursday() {
        assertEquals("Thursday", DayOfWeek.getDayOfWeek('T', 'h'));
    }

    @Test
    public void testSaturday() {
        assertEquals("Saturday", DayOfWeek.getDayOfWeek('A', 'a'));
    }

    @Test
    public void testInvalidInput() {
        assertEquals("Invalid input", DayOfWeek.getDayOfWeek('X', 'x'));
    }
}

在测试类中，设计了最少的测试数据来满足语句覆盖测试。每个测试方法对应一条测试数据，使用assertEquals方法判断期望结果值和实际返回值是否一致。