1.去除值未null的項
List<String> list = new ArrayList<String>();
list .removeAll(Collections.singleton(null));
實例:
List<String> list = new ArrayList<String>();
list.add(null);
list.add("1");
list.add(null);
System.out.println("***************去除null之前");
for(String str : list) {
System.out.println(str);
}
list .removeAll(Collections.singleton(null));
System.out.println("**************去除null之後");
for(String str : list) {
System.out.println(str);
}