当我使用PriorityQueItem.add（E item）方法时，我不断收到ArrayStoreError。我的代码流程是......
if (student.deductCoins(coins)) { //if the student has enough coins...
PriorityQueueItem<Student> newPQI = new PriorityQueueItem<Student>
(coins); //...create a new PriorityQueueItem<E> object
// using that amount for the priority
newPQI.add(student); //add the student to the queue associated with this
//PriorityQueueItem object
...在Course类中，然后我的PriorityQueItem.add（E项）是......
public void add(E item) {getList().enqueue(item);}
...使用Queue<E>.enqueue(E item)方法将添加内容添加到new PriorityQueueItem<E>的队列中。每个PriorityQueueItem都有一个整数值，并在创建时分配给它Queue<E> queue; getList()获取队列。
根据堆栈跟踪，当到达queue[front]=item中的行Queue<E>.enqueue(E item)时会触发错误。根据API，当您尝试将错误类型的项添加到数组时会发生ArrayStoreException，但我无法看到此序列中的位置。任何帮助将不胜感激。
@Erin和@Thomas：
/ ** * *用于表示存储在PriorityQueue中每个条目的对象的类。即， * {@link PriorityQueue}的内部节点结构 * * @author CS367 * * @param *存储在列表中的数据内容的泛型类型 * / 公共类PriorityQueueItem实现Comparable＆gt; {
private int priority;
private Queue<E> queue;
public PriorityQueueItem(int priority) {
this.priority = priority;
this.queue = new Queue<E>();
}
public int getPriority() {
// TODO
return this.priority;
}
public Queue<E> getList() {
// TODO
return this.queue;
}
/**
* Add an item to the queue of this PriorityQueueItem object
* @param
*
* @param student
* item to add to the queue
*/
public void add(E item) {
getList().enqueue(item);
}
/**
* Compares this Node to another node on basis of priority
*
* @param o
* other node to compare to
* @return -1 if this node's priority is lesser, +1 if this nodes priority
* is higher after, else 0 if priorities are the same.
*/
@Override
public int compareTo(PriorityQueueItem<E> o) {
int x = 0;
if (this.getPriority() > o.getPriority())
x = 1;
if (this.getPriority() == o.getPriority())
x = 0;
if (this.getPriority() < o.getPriority())
x = 1;
return x;
}
}
/ ** *有序的物品收集，其中物品被添加到后面并被移除 * 从前面。 * / 公共类Queue实现QueueADT {
private static final int MAX_CAPACITY = 100;
private E[] queue;
private int size;
private int front;
private int rear;
// TODO
// You may use a naive expandable circular array or a chain of listnodes.
// You may NOT use Java's predefined classes such as ArrayList or
// LinkedList.
@SuppressWarnings("unchecked")
public Queue() {
this.queue = (E[]) new Array [MAX_CAPACITY];
this.size = 0;
this.front = 0;
this.rear = 0;
}
/**
* Adds an item to the rear of the queue.
*
* @param item
* the item to add to the queue.
* @throws IllegalArgumentException
* if item is null.
*/
public void enqueue(E item) {
if (item == null) {
throw new IllegalArgumentException();
}
// if number of items exceeds size limits of the array
// then expand the array
if (!(size < queue.length - 1)) {
this.expandCapacity();
}
queue[rear] = item;
if (rear < queue.length - 1) {
rear++;
} else {
rear = 0;
}
size++;
}
/**
* Removes an item from the front of the Queue and returns it.
*
* @return the front item in the queue.
* @throws EmptyQueueException
* if the queue is empty.
*/
public E dequeue() {
if (isEmpty()) {
throw new EmptyQueueException();
}
E next = this.queue[front];
queue[front] = null;
if (this.front < queue.length - 1) {
this.front++;
} else {
this.front = 0;
}
size--;
return next;
}
/**
* Returns the item at front of the Queue without removing it.
*
* @return the front item in the queue.
* @throws EmptyQueueException
* if the queue is empty.
*/
public E peek() {
return this.queue[front];
}
/**
* Returns true iff the Queue is empty.
*
* @return true if queue is empty; otherwise false.
*/
public boolean isEmpty() {
return this.size == 0;
}
/**
* Removes all items in the queue leaving an empty queue.
*/
public void clear() {
while (!isEmpty()) {
this.dequeue();
}
}
/**
* Returns the number of items in the Queue.
*
* @return the size of the queue.
*/
public int size() {
return this.size;
}
@SuppressWarnings("unchecked")
private void expandCapacity() {
E[] newQueue;
newQueue = (E[]) Array.newInstance(PriorityQueueItem.class,
this.size() * 2);
for (int i = 0; i < queue.length; i++) {
newQueue[i] = this.queue[i];
}
this.queue = newQueue;
}
}