Map的几种遍历

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class Test9_26 {
@SuppressWarnings("unchecked")
public static void work(Map map) {
Collection c = map.values();
Iterator it = c.iterator();
for (; it.hasNext();) {
System.out.println(it.next());
}
}

// 利用keyset进行遍历，它的优点在于可以根据你所想要的key值得到你想要的 values，更具灵活性！！
@SuppressWarnings("unchecked")
public static void workByKeySet(Map map) {
Set<String> key = map.keySet();
for (Iterator it = key.iterator(); it.hasNext();) {
String s = (String) it.next();
System.out.println(map.get(s));
}
}

// 比较复杂的一种遍历在这里，呵呵~~他很暴力哦，它的灵活性太强了，想得到什么就能得到什么~~
@SuppressWarnings("unchecked")
public static void workByEntry(Map map) {
Set<Map.Entry> set = map.entrySet();
for (Iterator<Map.Entry> it = set.iterator(); it.hasNext();) {
Map.Entry entry = (Map.Entry) it.next();
System.out.println(entry.getKey() + "--->" + entry.getValue());
}
}

@SuppressWarnings("unchecked")
public static void main(String[] args) {
Map m = new HashMap();
m.put("1", "zhang,12");
m.put("2", "li,14");

Test9_26.work(m);
System.out.println("==================");

Test9_26.workByKeySet(m);
System.out.println("==================");

Test9_26.workByEntry(m);
}
}