实验内容：

信用卡号是一串长度介于13和16之间的一串数字。卡号必须是以4、5、6、或37开头，并遵循下面模式：

1)    从卡号最后一位数字开始,偶数位乘以2,如果乘以2的结果是两位数，那么就将这两位数加在一起得到一位数。

2)    将第一步所得到的所有一位数相加

3)    从卡号最后一位数字开始,奇数位数字相加

4)    将第二步和第三步的到的结果相加

5)    如果第四步得到的结果能被10整除，那么卡号是合法的，否则，卡号是不合法的。

package org.test;import java.util.Scanner;public class CreditCard {    /** Return true if the card number is valid */  public boolean isValid(long number) {    return  (getSize(number) >= 13) && (getSize(number) <= 16) &&         (prefixMatched(number, 4) || prefixMatched(number, 5) ||        prefixMatched(number, 6) || prefixMatched(number, 37)) &&        (sumOfDoubleEvenPlace(number) + sumOfOddPlace(number)) % 10 == 0;  }  /** Get the result from Step 2 */  public int sumOfDoubleEvenPlace(long number) {    int result = 0;        number = number / 10; // Starting from the second digit from left    while (number != 0) {      result += getDigit((int)((number % 10) * 2));      number = number / 100; // Move to the next even place    }        return result;  }    /** Return this number if it is a single digit, otherwise, return    * the sum of the two digits */  public int getDigit(int number) {    return number % 10 + (number / 10);  }    /** Return sum of odd place digits in number */  //3)	从卡号最后一位数字开始,奇数位数字相加  public int sumOfOddPlace(long number) {    int result = 0;       while (number != 0) {      result += (int)(number % 10);      number = number / 100; // Move two positions to the left    }        return result;  }    /** Return true if the digit d is a prefix for number */  public boolean prefixMatched(long number, int d) {    return getPrefix(number, getSize(d)) == d;  }    /** Return the number of digits in d */  public int getSize(long d) {    int numberOfDigits = 0;        while (d != 0) {      numberOfDigits++;      d = d / 10;    }        return numberOfDigits;  }    /** Return the first k number of digits from number. If the number   * of digits in number is less than k, return number. */  public long getPrefix(long number, int k) {    long result = number;        for (int i = 0; i < getSize(number) - k; i++)      result /= 10;        return result;  }}

　　

 

参数化 && 覆盖率100% 测试设计:

package org.test;import static org.junit.Assert.*;import java.util.Arrays;import java.util.Collection;import org.junit.After;import org.junit.AfterClass;import org.junit.Assert;import org.junit.Before;import org.junit.BeforeClass;import org.junit.Test;import org.junit.runner.RunWith;import org.junit.runners.Parameterized;import org.junit.runners.Parameterized.Parameters;@RunWith(Parameterized.class)  public class CreditCardTest {	CreditCard creditCard;	private long input;	private int sumOfOddPlaceExpected;	private int digitExpected;	private int sumOfDoubleEvenPlaceExpected;	private boolean isValidExpected;	 @Parameters  	 @SuppressWarnings("unchecked")  	  public static Collection prepareData1(){  	        Object[][] object = {	        		{4111111111111111L,8,8,22,true},	        		{38520000023237L,21,3,19,false},	        		{6011000000000004L,5,5,5,true},	        		{100000000L,1,1,0,false},	        		{10000000000000000L,1,1,0,false},	        		{371449635398431L,33,6,47,true},	        		{5111111111111198L,15,6,22,false}	               };  	       	       return Arrays.asList(object);  	   } 		 public CreditCardTest(long input,int sumOfOddPlaceExpected,int digitExpected,			 int sumOfDoubleEvenPlaceExpected,boolean isValidExpected){  	        this.input = input;  	        this.sumOfOddPlaceExpected = sumOfOddPlaceExpected;  	        this.digitExpected = digitExpected;	        this.sumOfDoubleEvenPlaceExpected = sumOfDoubleEvenPlaceExpected;	        this.isValidExpected = isValidExpected;	 }	 		@Before	public void setUp() throws Exception {		 creditCard = new CreditCard();	}	//检验信用卡号	@Test	public void testIsValid() {		boolean result = creditCard.isValid(input);		Assert.assertEquals(isValidExpected,result);	}	//从卡号最后一位数字开始,偶数位乘以2,如果乘以2的结果是两位数，那么就将这两位数加在一起得到一位数。	@Test	public void testSumOfDoubleEvenPlace() {		int result = creditCard.sumOfDoubleEvenPlace(input);		Assert.assertEquals(result, sumOfDoubleEvenPlaceExpected);	}	//如果两位数，那么就将这两位数加在一起得到一位数，否则返回本身	@Test	public void testGetDigit() {		int result = creditCard.getDigit(sumOfOddPlaceExpected);		Assert.assertEquals(digitExpected, result);	}	//3)从卡号最后一位数字开始,奇数位数字相加	@Test	public void testSumOfOddPlace() {		 int result = creditCard.sumOfOddPlace(input);	     Assert.assertEquals(sumOfOddPlaceExpected,result);  	}}