在Java中使用HashTable的问题(Issues with using HashTable in Java)

 我正在尝试使用哈希表，当我试图搜索一个对象时，我没有看到该对象，但是如果我打印它我就能看到它。 
 
 节点类： 
 
public class Node {

    int x;
    int y;


    public Node() {

        this.x=0;
        this.y=0;

    }

    public Node(int x,int y) {
        this.x=x;
        this.y=y;
    }



    public String toString(){

        return "(Node: x,y="+Integer.toString(x)+","+Integer.toString(y)+")";

    }

}
 
 主类： 
 
public class GridWalk {


    static Hashtable <Node, Integer> myMap;
    static Stack<Node> nodes;

    public static void main(String[] args) {

        myMap = new Hashtable<Node,Integer>();
        nodes=new Stack<Node>();

        Node start=new Node(0,0);

        Node new1= new Node(100,100);
        myMap.put(new1,new Integer(1));
        Node new2=new Node (100,100);
        System.out.println("Already there ? huh: "+new2.toString()+" at "+myMap.get(new2)); 

    }
}
 
 我在打印行时得到NULL。 知道为什么吗？ 

I am trying to use hashtable and when trying to search for an object,I do not see the object, but I can see it if I print it. 
 
Node Class:
 
public class Node {

    int x;
    int y;


    public Node() {

        this.x=0;
        this.y=0;

    }

    public Node(int x,int y) {
        this.x=x;
        this.y=y;
    }



    public String toString(){

        return "(Node: x,y="+Integer.toString(x)+","+Integer.toString(y)+")";

    }

}
 
Main Class:
 
public class GridWalk {


    static Hashtable <Node, Integer> myMap;
    static Stack<Node> nodes;

    public static void main(String[] args) {

        myMap = new Hashtable<Node,Integer>();
        nodes=new Stack<Node>();

        Node start=new Node(0,0);

        Node new1= new Node(100,100);
        myMap.put(new1,new Integer(1));
        Node new2=new Node (100,100);
        System.out.println("Already there ? huh: "+new2.toString()+" at "+myMap.get(new2)); 

    }
}
 
I am getting NULL when I do the print line. Any idea why ?

原文：https://stackoverflow.com/questions/9651641