Java 可比<；T>；不为treemap工作

我正在尝试构建一个树映射，并且已经为密钥类实现了我自己的可比较接口，但是我仍然得到一个“不能转换为可比较”的异常，我真的不明白为什么。以下是我的代码的相关部分：

接口：

public interface Comparable<T> {

public int compareTo(T o);

}

---

然后返回PriorityBuy无法解析为Compariable的异常。但我似乎已经建立了这个程序，这样应该可以工作了。那么……谁能帮我看看为什么它不是？

你不能创建自己的

可比的
界面；您必须使用内置的
java.lang.Compariable
您不能创建自己的
Compariable
界面；您必须使用内置的
java.lang.Comparable
好的，那么我如何使用java.lang.Comparable实现一个可比较的接口呢？这是否等于删除了我编写的接口？编辑：没关系，我是个白痴。谢谢你帮我看。：）好的，那么如何使用java.lang.comparable实现一个可比较的接口呢？这是否等于删除了我编写的接口？编辑：没关系，我是个白痴。谢谢你帮我看。：）
public class PriorityBuy implements Comparable<PriorityBuy>{

protected double _priceDouble;
protected DollarValue _priceDollarValue = new DollarValue(_priceDouble);
protected Price _price = new Price(_priceDollarValue);
protected long _time;

public PriorityBuy(Price price, long time) {

    this._price = price;
    this._time = time;

}

public Price getPrice() {
    return _price;
}

public long getTime() {
    return _time;
}

/**
 * The following provides a new choice of hash function for this class.  The reason is that
 * we need to create a new equals method to match the compareTo method, and we need to know
 * that equal objects return equal hashCode.
 */

@Override
public int hashCode() {
    return (int) (((_price.hashCode())*13)^(_time));
}

/**
 * We re-implement the equals method to match our compareTo method, which depends on both price
 * and on time.
 */

@Override
public boolean equals(Object o) {
    if(! (o instanceof PriorityBuy)) {
        return false;
    }
    PriorityBuy p = (PriorityBuy) o;
    if(p.getPrice().getDollarValue().getValue() == _price.getDollarValue().getValue() && p.getTime() == _time) {
        return true;
    }

    return false;
}

/**
 * We are writing a compareTo method so that this class can implement Comparable<Priority>, which
 * in turn allows any treemap constructed with Priority as the class of keys to order the tree
 * according to the ordering defined by the compareTo method defined below, instead of using
 * the "natural ordering" as it usually does.
 */

@Override
public int compareTo(PriorityBuy a) {

    if(a.getPrice().getDollarValue().getValue() > this.getPrice().getDollarValue().getValue()) {
        return -1;
    }
    else if(a.getPrice().getDollarValue().getValue() < this.getPrice().getDollarValue().getValue()) {
        return 1;
    }
    else if(a.getTime() < this.getTime()) {
        return -1;
    }
    else if(a.getTime() > this.getTime()) {
        return 1;
    }
    else {
        return 0;   
    }
}


}

public void addToBuyBook(OrderBookMessage obm) throws Exception {
    Order order = this.createOrder(obm);
    TreeMap<PriorityBuy,Order> buyBookTree = _buyBook.get(obm.getTicker());
    buyBookTree.put(order.getPriorityBuy(), order);
    _buyBook.put(obm.getTicker(), buyBookTree);
    this.addBuyOrder(obm.getOrderID(), obm.getTicker(), obm.getLimitPrice(), obm.getQuantity());
}

public void testAddToBuyBook() throws Exception {
    OrderBookManager manager = new OrderBookManager();
    OrderBookMessage obm1 = new OrderBookMessage("IBM");
    OrderBookMessage obm2 = new OrderBookMessage("IBM");

    manager.addToBuyBook(obm1);

    manager.addToBuyBook(obm2);


}