多输入法 java

Question

I have a interface and in the interface I want to declare a method such that it can take any number of objects as input.

Something like this:

interface Implementable{
     public ReturnObj doIt(objects ....);
}

Please advise

Answer 1

The correct syntax would in your case be:

interface Implementable{
    public ReturnObj doIt(Object... objs);
}

Official documentation for var-arg methods is found here .

I was about to ask the difference between varargs and passing an array,

Varargs gets compiled into an argument of an array-type. The only difference is with the vararg syntax, method calls such as

doIt("hello", "world");

will be compiled into

doIt(new Object[] { "hello", "world" });

In other words, given a declaration such as

public ReturnObj doIt(Object[] objs);

you'll have

doIt(new Object[] { "hello", "world" });  // works fine
doIt("hello", "world");                   // won't compile

while given the var-arg declaration, both method calls will compile and be equivalent.

Answer 2

Pass an array:

public ReturnObj doIt(Object[] input);

or use the equivalent varargs expression

public ReturnObj doIt(Object... input);

Answer 3

1. You need to understand varargs first.
2. What is the question?

Example:

interface Implementable{
    public ReturnObj doIt(Object... object);
}

Alternatively (which I should prefer, especially in Web Services design):

interface Implementable{
    public ReturnObj doIt(Object[] object);
}

Answer 4

You forgot to ask a question, but assuming you want to know how to declare a method which takes variable number of arguments, check out this link:

http://download.oracle.com/javase/1,5.0/docs/guide/language/varargs.html

So it would be

interface Implementable{

         public ReturnObj doIt(Object... objects);
}