代码（修改版，可运行）
package tjuscsst_hw3;
public class hw3 {
/** *****************************************************
* Finds and prints n prime integers
* Jeff Offutt, Spring 2003
********************************************************* */
private static int MAXPRIMES = 10000;
private static boolean isDivisible(int a, int b)
{
if(b%a == 0)
{
return true;
}
return false;
}
static void printPrimes (int n)
{
int curPrime; // Value currently considered for primeness
int numPrimes; // Number of primes found so far.
boolean isPrime; // Is curPrime prime?
int [] primes = new int [MAXPRIMES]; // The list of prime numbers.
// Initialize 2 into the list of primes.
primes [0] = 2;
numPrimes = 1;
curPrime = 2;
while (numPrimes < n)
{
curPrime++; // next number to consider ...
isPrime = true;
for (int i = 0; i <= numPrimes-1; i++)// for each previous prime.
{
if (isDivisible (primes[i], curPrime))// Found a divisor, curPrime is not prime.
{
isPrime = false;
break; // out of loop through primes.
}
}
if (isPrime)// save it!
{
primes[numPrimes] = curPrime;
numPrimes++;
}
} // End while
// Print all the primes out.
for (int i = 0; i <= numPrimes-1; i++)
{
System.out.println ("Prime: " + primes[i]);
}
} // end printPrimes
}问题与答案
q1:Draw the control ?ow graph for the printPrimes() method.
a1:控制流图如下所示：
q2: Consider test cases t1 = (n = 3) and t2 = ( n = 5). Although these tour the same prime paths in printPrime(), they don‘t necessarily find
the same faults. Design a simple fault that t2 would be more likely to discover than t1 would.
a2: 当MAXPRIMES的值为3或者4时，t2的测试样例会在保存素数到数组时发生数组越界错误。
q3: For printPrimes(), find a test case such that the corresponding test path visits the edge that connects the beginning of the while statement to the for statement without going through the body of the while loop.
a3: test = (n = 1)
q4: Enumerate the test requirements for node coverage, edge coverage, and prime path coverage for the graph for printPrimes().
a4:
node coverage: {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}
edge coverage: {(0,1),(1,2),(2,3),(3,4),(4,5),(4,8),(8,3),(3,6),(5,6),(6,7),(6,9),(7,10),(9,10),(10,1),(1,11),(11,12),(12,13),(13,14),(14,12),(12,15)}
prime path coverage:{(0,1,2,3,4,5,6,7,10),(0,1,2,3,4,5,6,9,10),(0,1,2,3,4,8),(1,2,3,6,7,10,1),(3,4,8,3),(0,1,11,12,13,14),(0,1,11,12,15),(12,13,14,12),(13,14,12,15),(4,8,3,6,7,10,1,11,12,15),(4,8,3,6,9,10,1,11,12,15),(4,8,3,6,9,10,1,11,12,13,14),(4,8,3,6,7,10,1,11,12,13.14),(2,3,6,7,10,1,11,12,13,14),(2,3,6,7,10,1,11,12,15),(2,3,6,9,10,1,11,12,13,14),(2,3,6,9,10,1,11,12,15),(2,3,4,5,6,7,10,1,11,12,13,14),(2,3,4,5,6,7,10,1,11,12,15),(2,3,4,5,6,9,10,1,11,12,13,14),(2,3,4,5,6,9,10,1,11,12,15)}
基于Junit及Eclemma(jacoco)实现一个主路径覆盖的测试
测试代码
package tjuscsst_hw3;
import static org.junit.Assert.*;
import org.junit.Test;
public class hw3Test {
private hw3 test = new hw3();
@Test
public void test() {
test.printPrimes(5);
}
}
测试结果
