Question

java判断对象是否为空

Answer 1

public static boolean isNullOrEmpty(Object obj){
if (obj == null)
return true;

if (obj instanceof CharSequence)
return ((CharSequence) obj).length() == 0;

if (obj instanceof Collection)
return ((Collection) obj).isEmpty();

if (obj instanceof Map)
return ((Map) obj).isEmpty();

if (obj instanceof Object[]) {
Object[] object = (Object[]) obj;
if (object.length == 0) {
return true;
}
boolean empty = true;
for (int i = 0; i < object.length; i++) {
if (!isNullOrEmpty(object[i])) {
empty = false;
break;
}
}
return empty;
}
return false;
}

Answer 2

(object)!=null 返回是逻辑值

Answer 3

if(对象 == null){
****

}else{
****
}

Answer 4

public boolean isNotBlank(Object obj){
if(obj!=null){
return true;
}
return false;
}

Answer 5

bean!=null

额 话说 你要问得是这个么？