hashmap 遍历

package practice31_2;

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

public class hashmapkeyvalue2 {

public static void main(String[] args) {
HashMap<String, String> map = new HashMap<String,String>();
map.put("美利坚省","北美");
map.put("日本省","东亚");
map.put("俄罗斯省","欧洲");
map.put("加拿大省","南美");
map.put("南非省","非洲");

//遍历HASHMAP的三种方式
Set keySet = map.keySet();
for (String key : keySet) {

System.out.println(key + map.get(key));
}

System.out.println("***********************");

Iterator iterator1 = map.keySet().iterator();
while (iterator1.hasNext()) {
String key = (String) iterator1.next();

System.out.println(key +map.get(key));

}
System.out.println("***********************");

Collection values = map.values();
for (String val : values) {

System.out.println(val);
}
System.out.println("***********************");

Iterator iterator2 = map.values().iterator();
while (iterator2.hasNext()) {
String values1 = (String) iterator2.next();
System.out.println(values1);
}
System.out.println("***********************");

Set<Entry<String, String>> entrySet = map.entrySet();

for (Entry<String, String> entry : entrySet) {
System.out.println(entry);
}
System.out.println("***********************");
Iterator<Entry<String, String>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<java.lang.String, java.lang.String> entry =
(Map.Entry<java.lang.String, java.lang.String>) iterator
.next();

System.out.println(entry);
}
}
}