数字数组：
int[] num=new int[]{
   
   4,2,7,2,4,9}
List<Integer>list =new ArrayList<Integer>(); 
for(int i=0;i<num.length;i++){
    if(!list.contains(num[i])){
        list.add(num[i]);
    }
}

字符数组：
String[] str=new String[]{
   
   "java","C++","php","java"}
List<String>list =new ArrayList<String>(); 
for(int i=0;i<str.length;i++){
    if(!list.contains(str[i])){
        list.add(str[i]);
    }
}