HashMap获取键值的用法

package test;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;

public class TestA {
//初始化HashMap数据 ,(static只静态分配一次内存,jvm加载类时就会执行)
public static HashMap<?, ?> initHashMapValue(){
HashMap<Integer, String> hm=new HashMap<Integer, String>();
for (int i = 1; i <=10; i++) {
hm.put(i, "hello"+i);
}
return hm;
}
//keySet获取key
public  void getHashMapKeyMethod(){
Iterator<?> it=initHashMapValue().keySet().iterator();
while(it.hasNext()){
Object key=(Object)it.next();
System.out.println("hashMap Key:"+key);
//System.out.println("hashMap Value:"+hm.get(key));
System.out.println("============================");
}
}
//values获取值
public  void getHashMapValueMethod(){

Iterator<?> it=initHashMapValue().values().iterator();
while (it.hasNext()) {
System.out.println("Values:"+it.next());
System.out.println("****************************");
}

}
@SuppressWarnings("unchecked")
//entrySet获取key和value
public  void getHashMapKeyAndValueMethod(){
Iterator<?> it=initHashMapValue().entrySet().iterator();
while (it.hasNext()) {
java.util.Map.Entry o=(Entry)it.next();
System.out.println("key:"+o.getKey());
System.out.println("Values:"+o.getValue());
}
}
//对hashMap进行排序
public void sortHashMap(){
   Object[] key =initHashMapValue().keySet().toArray();
       Arrays.sort(key);
       for (int i = 0; i < key.length; i++) {
           System.out.println(initHashMapValue().get(key[i]));
       }

}
public  void testHashMap(){
this.getHashMapKeyMethod();
this.getHashMapValueMethod();
this.getHashMapKeyAndValueMethod();
this.sortHashMap();
}

public static void main(String[] args) {
TestA test = new TestA();
test.testHashMap();

}

}