问一个简单的算法有关问题

问一个简单的算法问题
有这么两个字符串数组
String strA = {"h","k","i", "e"}
String strB = {"a","b","c","d","e","f","g","h","i","j","k"}

现在我要找出strA和strB的交集并输出，请问要怎么做？
如果按照这种方法效率肯定不高，要怎样改进？

Java code

for(String str1 : strA){    for(String str2 : strB)    {        if(str1.equals(str2))           ....    }}

Java code

String[] strA = {"h","k","i", "e"};String[] strB = {"a","b","c","d","e","f","g","h","i","j","k"};List<String> l1 = new ArrayList<String>(Arrays.asLit(strA));List<String> l2 = new ArrayList<String>(Arrays.asLit(strB));l1.retainAll(l2); //交集 l1.removeAll(l2)差集 l1.addAll(l2)并集String[] sab = l1.toArray(new String[0]);for (String s : sab) {    System.out.println(s);}