Hello I have the following issue
I have the following function signature :
public void doSomething(Object arg);
I call this function with the following code segment :
doSomething(new Object[] {this,"aString"});
In the doSomething method implementation how can I read the data (Class Name and String) that I sent when I called it ?
public static void doSomething(Object arg) {
if (arg instanceof Object[]) {
Object[] list = (Object[]) arg;
for (Object item : list) {
System.out.println(item);
}
}
}
This assumes you will always pass an Object[] as argument.
To check whether the passed object is actually an array use
if(obj instanceof Object[]) ...
You can introspect the variable passed in using instanceOf method
arg instanceof Object[]
returns boolean.
Or check the class name of the pass variable by calling arg.getClass()
arg.getClass()
return class name as String.
You can do the following:-
public void doSomething(Object arg){
Object[] arr=(Object[])arg; // cast the arg into Object[] array
Object obj=arr[0] ;// will return the object
String s=(String)arr[1] ;// would return string (add a down-cast to string because that string object when added to array converts to the Object type)
System.out.println(obj+" "+s);
}
If you called it in this way
doSomething(new Object[] {this,"aString"});
Ouput would be something like this:-
Class@dce1387 aString
use
arg.getClass().getSimpleName() to get Class Name
arg.getClass() to get fully qualified Class Name
arg.toString() to read the data which converts to string.
Assuming you have overidden toString() method
Object[](as you mentioned in one of your comments) change the method signature to `public void doSomething(Object[] arg).