我有此代码的IntLinkedList类
public class IntLinkedList {
private Node head;
public void addFirst(int data) {
head = new Node(data, head);
}
public Node copy(){
Node current = head; // used to iterate over original list
Node newList = null; // head of the new list
Node tail = null; // point to last node in new list
while (current != null)
{
// special case for the first new node
if (newList == null)
{
newList = new Node(current.data, null);
tail = newList;
}
else
{
tail.next = new Node(current.data, null);
tail = tail.next;
}
current = current.next;
}
return newList;
}
private class Node {
int data;
Node next;
Node(int data, Node next) {
this.data = data;
this.next = next;
}
}
}
并且我正在尝试使用以下JUnit代码测试copy方法
public class IntLinkedListTest {
/** Reference to linked list under test */
private IntLinkedList lst;
/** Creates a linked list for testing. */
@Before
public void setUp() {
lst = new IntLinkedList();
lst.addFirst(30);
lst.addFirst(10);
lst.addFirst(40);
lst.addFirst(20);
}
/** Tests copying a non-empty list. */
@Test
public void testCopy() {
IntLinkedList cpy = lst.copy();
assertEquals(lst.toString(), cpy.toString());
}
}
我想从Copy()方法获得IntLinkedList类返回的列表,并在JUnit中对其进行测试。我也尝试返回IntLinkedList和Object类型,但是我不断收到诸如“类型不匹配:无法从IntLinkedList.Node转换为IntLinkedList”之类的错误。我对LinkedList的经验很少,但是对Java类,对象的引用却很有经验,但这对我来说是新领域。有人可以帮忙吗?
Solution:-您正在将Node
类toString与IntLinkedList
类toString进行比较,从而导致Junit失败,尝试覆盖Node和IntLinkedList类的toString()
方法,您会清楚地看到堆栈跟踪为] >
org.junit.ComparisonFailure: expected:<[IntLinkedList [head=Node [data=20, next=Node [data=40, next=Node [data=10, next=Node [data=30, next=null]]]]]]> but was:<[Node [data=20, next=Node [data=40, next=Node [data=10, next=Node [data=30, next=null]]]]]>
此Junit正常工作
:-因为您的Node类是私有的,所以我做了一个较小的更改以使@Test public void testCopy() { IntLinkedList.Node cpy = lst.copy(); assertEquals(lst.copy().toString(), cpy.toString()); }
编辑
IntLinkedList.Node
工作,因此我将签名更改为static以使junit工作,即static class Node {
嗯