TreeMap排序

package com;

import java.util.Comparator;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;

public class TestTreeMap {
public static void main(String[] args) {
Map<String,String> map =new TreeMap<String, String>(new Comparator<String>() {
@Override
public int compare(String o1, String o2) {
int i=o1.compareTo(o2);
return i;
}
});

map.put("cc", "cc");
map.put("ee", "ee");
map.put("aa", "aa");
map.put("bb", "bb");
map.put("dd", "dd");

System.out.println("通过Map.entrySet遍历key和value");
for (Map.Entry<String, String> entry : map.entrySet()) {
System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());
}

System.out.println("通过Map.keySet遍历key和value：");
for (String key : map.keySet()) {
System.out.println("key= "+ key + " and value= " + map.get(key));
}

System.out.println("通过Map.entrySet使用iterator遍历key和value：");
Iterator<Map.Entry<String, String>> it = map.entrySet().iterator();
while (it.hasNext()) {
Map.Entry<String, String> entry = it.next();
System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());
}

System.out.println("通过Map.values()遍历所有的value，但不能遍历key");
for (String v : map.values()) {
System.out.println("value= " + v);
}

}
}