1 Integer对象的比较用equals或者compareTo;
2 To successfully store and retrieve objects from a hashtable, the objects used as keys must implement the hashCode method and the equals method 这是jdk文档的原话，通常要实现hashCode和equals方法
下面简单给出修改后的代码
import java.util.*;
public class Hashtabletest {
public static void main(String args[])
{
Hashtable hs = new Hashtable();
for(int i = 0; i < 10; i++)
hs.put(new Integer(i), new String(i + "aa"));
if(hs.containsKey(new Integer(0)))
System.out.println("OK");
else
System.out.println("SORRY");
System.out.println((new Integer(1)).equals(new Integer(1)));
Hashtable hs1 = new Hashtable();
for(int i = 0; i < 10; i++)
hs1.put(new hashelement(i), new String(i + "aa"));
if(hs1.containsKey(new hashelement(0)))
System.out.println("OK");
else
System.out.println("SORRY");
}
}
class hashelement
{
int n = 0;
hashelement(int i)
{
n = i;
}
public int getN() {
return n;
}
public boolean equals(Object hs) {
return (this.n == ((hashelement)hs).getN());
}
public int hashCode() {
return n;
}
}
运行结果为：
OK
true
OK
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于 2005-09-28 00:10
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