java中“集合”与“数组”转换

StringArray与 Set转换

• 数组->Set集合：将数组转换成List，List在转换成Set
• Set集合->数组：利用Set集合中toArray，并提供数组类型

public class CollectionsAndArrays {    //String[]->HashSet    public static  Set<String> arraysToCollections(String[]values){        Set<String> aSet=new HashSet<>(Arrays.asList(values));        return aSet;    }    //HashSet->String[]    public static String[] collectionsToArrays(Set<String> aSet){               return aSet.toArray(new String[aSet.size()]);    }    public static void main(String[] args){        String[] values={"this","is","a","string","array"};        //数组转集合        Set<String>aSet=arraysToCollections(values);        System.out.println(aSet);        //集合转数组        String [] values1=collectionsToArrays(aSet);        for(String s:values1)            System.out.print(s+" ");            }}/*输出：    [is, string, a, this, array]    is string a this array*/