Hashtable的使用方法介绍
1*****************************************************************import java.util.Dictionary;import java.util.Enumeration;import java.util.Vector;@SuppressWarnings("rawtypes")public class HashTable1 extends Dictionary{ //Dictionary是个什么东东？private Vector keys = new Vector();private Vector values = new Vector();@Overridepublic Enumeration elements() {return values.elements();}@Overridepublic Object get(Object key) { int index = keys.indexOf(key); if(index == -1){ return null; }return values.elementAt(index);}@Overridepublic boolean isEmpty() {return keys.isEmpty();}@Overridepublic Enumeration keys() {return keys.elements();}@SuppressWarnings("unchecked")@Overridepublic Object put(Object key, Object value) { keys.addElement(key); values.addElement(value); return key;}@Overridepublic Object remove(Object key) { int index = keys.indexOf(key); if(index == -1){ return null; } keys.removeElementAt(index); Object returnval = values.elementAt(index); values.removeElementAt(index);return returnval;}@Overridepublic int size() {return keys.size();}public static void main(String are[]){HashTable1 ht = new HashTable1();for(char c = 'a' ;c <= 'z';c++){ht.put(String.valueOf(c), String.valueOf(c).toUpperCase());}char [] ca = {'a','e','i','o','u'};for(int i=0;i<ca.length;i++){System.out.println("Uppercase: "+ht.get(String.valueOf(ca[i])));}}}//Vector 具有的方法：size() removeElementAt() addElement() elements() get() // indexOf() elementAt() 等等2***********************************************************************import java.util.Hashtable;class Counter{int i=1;public String toString(){return Integer.toString(i);}}public class HashTable2 {@SuppressWarnings({ "rawtypes", "unchecked" })public static void main(String args[]){Hashtable ht = new Hashtable();for(int i=0;i<1000;i++){Integer r = new Integer((int)(Math.random()*20));if(ht.containsKey(r)){((Counter)ht.get(r)).i++;}else{ht.put(r, new Counter());}}System.out.println(ht);}}*******************************************************************import java.util.*;public class HashtableTest_1 {public static void main(String[] args) {Hashtable<String, String> hh = new Hashtable<String, String>();hh.put("a", "name"); // 姓名hh.put("b", "age"); // 年龄hh.put("c", "address"); // 地址hh.put("d", "wage"); // 工资Enumeration<String> er = hh.keys();//返回此哈希表中的键的枚举while (er.hasMoreElements()) {//判断此枚举是否包含更多的元素。Object o = er.nextElement();//返回此枚举的下一个元素，也就是key值 Object v = hh.get(o); //根据key将value取出System.out.println(o + "=" + v);}}}