package test;
import java.util.*
;
/**
* Created by ming
*/
public class Test {
public static void main(String[] args) {
Set<Long> longSet=
new HashSet<>
();
longSet.add(1L
);
longSet.add(2L
);
List<Long> longList=
new ArrayList<>
();
longList.addAll(longSet);//list转set
for(Long t : longList){
System.out.println(t);
}
Set<Long> set2=
new HashSet<>
();
set2.addAll(longList);//list转set
for(Long s : set2){
System.out.println(s);
}
Map<Long,Long> map=
new HashMap<>();
//list转map
for(Long t : longList){
map.put(t,t);
}
for(Long s : set2){
//set转map
System.out.println(s);
}
Collection<Long> collections=
map.values();
for (Long t : collections){
System.out.println("map转集合"+
t);
}
Long longs[]={2L,3L,4L};
//定义一个数组
List<Long> longList1 = Arrays.asList(longs);
//数组转集合
for(Long t : longList1){
System.out.println("数组转集合"+
t);
}
Long [] newLongs= longList1.toArray(
new Long []{});
System.out.println("集合转数组的方法:"+
newLongs.length);
}
}
转载于:https://www.cnblogs.com/huzi007/p/5993949.html
相关资源：JAVA上百实例源码以及开源项目
