我浏览了该网站，找不到任何至少与我正在做的事情相媲美的东西（请不要链接我一直在寻找一个小时的任何 stackoverflow 回复或问题），所以我决定问这个问题。我正在尝试创建一个使用泛型的链接列表（不使用任何类型的库），这是所有相关代码。
public class LList<T>
{
MyNode<T> head = null;
MyNode<T> tail = null;
MyNode<T> temp = null;
int count = 0;;
Scanner scan = new Scanner(System.in);
//puts a new value at the edn of the list
public void add(T i)
{
if(head == null)
{
head = new MyNode<T>();
head.data = i;
head.next = tail;
tail = head;
}
else
{
tail.next = new MyNode<T>();
tail = tail.next;
tail.data = i;
}
count ++;
}
//inserts a new value at a given index
public void insert(int index, T item)
{
if(index == size())
{
add(item);
}
else if(index == 0)
{
MyNode<T> temp = new MyNode<T>();
temp.data = item;
temp.next = head;
head.previous = temp;
head = temp;
count++;
}
temp = head;
for(int i = 0; i < index-1; i++)
{
temp = temp.next;
MyNode<T> myNode = new MyNode<T>();
myNode.data = item;
myNode.next = temp.next;
temp.next = myNode;
count++;
}
}
//returns the number of values in the list
public int size()
{
return count;
}
//returns the value at a given index
public T get(int index)
{
if(head == null || index > count -1)
{
return null;
}
if(index < 0 || index >= count)
{
System.out.println("This does not exist");
}
MyNode<T> p = head;
int size = 0;
while(size < index && p.next != null)
{
p = p.next;
size++;
}
if(count != index)
{
return null;
}
else
{
return p.data;
}
}
//removes the returns the first value in the list
public T remove()
{
head = head.next;
head.previous = null;
count--;
return (T) head;
}
//removes and returns the value at a given index
public T removeAt(T elem)
{
temp = head;
MyNode<T> two = null;
if(head.data.equals(elem))
{
head = head.next;
head.previous = null;
count--;
return elem;
}
else if(tail.data.equals(elem))
{
tail = tail.previous;
tail.next = null;
count--;
return elem;
}
while(temp != null && !temp.data.equals(elem))
{
two = temp;
temp = temp.next;
}
if(temp == null)
{
return null;
}
two.next = temp.next;
T spare = temp.data;
temp = null;
count--;
return spare;
}
//removes and returns the last value in the list
public T removeLast()
{
temp = tail;
tail = tail.previous;
temp = null;
count--;
return (T) tail;
}
//creates a string representation of all the values in the list
public String toString()
{
String result = null;
for(int i = 0; i < count; i++)
{
result = i + " : " + get(i).toString();
}
return result;
}
//removes all the values in the list
public void clear()
{
for(int i = count -1; i >= 0; i++)
{
removeAt(i);
}
}
//searches for a value in the list and returns the first index of that
//value when found
public int search(T find)
{
if(head == null)
{
return -10;
}
MyNode<T> p = head;
do
{
if(find.compareTo(p.data) == 0)
{
return 0;
}
else
{
return -1;
}
p = p.next;
}while(p != null);
}
public void itemChosen(int choice, LLMenu[] menu)
{
LLMenu m = menu[choice-1];
switch(m)
{
case ADD:
System.out.println("What value would you like to add?");
T addThis = scan.nextInt();
add(addThis);
break;
case INSERT:
System.out.println("What index would you like to replace?");
T replace = scan.nextInt();
System.out.println("What number would you like to insert?");
int val = scan.nextInt();
insert(val, replace);
break;
case SIZE:
size();
break;
case GET:
System.out.println("What index would you like to look at?");
int thisOne = scan.nextInt();
get(thisOne);
break;
case REMOVE:
remove();
break;
case REMOVEAT:
System.out.println("What index would you like to remove?");
T thisHere = scan.nextInt();
removeAt(thisHere);
break;
case REMOVELAST:
removeLast();
break;
case TOSTRING:
toString();
break;
case CLEAR:
clear();
break;
case SEARCH:
System.out.println("What value would you like to search for?");
T searchForMe = scan.nextInt();
search(searchForMe);
break;
}
}
}
和我的节点：
public class MyNode<T>
{
T data;
MyNode<T> next;
MyNode<T> previous;
}
我真正遇到问题的地方是 LList 中的 switch 语句，我正在扫描应该设置为泛型的项目，显然没有使用扫描器读取泛型的方法。所以问题1，我如何读入并将它们设置为泛型，以及问题2，在我在LList 中的clear 方法中，如何在期望泛型时使用removeAt 时发送变量i？请保持所有答案的相关性，并感谢您的宝贵时间！
编辑 我的搜索方法中的另一个问题 do-while 有一个 if 语句说 if(find.compareTo(p.data) == 0) 我如何更改它以使其工作？我真的不知道该放什么，所以我只是把我的想法写下来。