如何创建一个接受Java中任何类型的任意数量的参数的方法？

Question

I can see there is a way to have a method in Java which accepts any number of arguments of a specified type: http://www.java-tips.org/java-se-tips/java.lang/how-to-pass-unspecified-number-of-arguments-to-am.html

but is there a way to make a method which accepts any number of arguments of any type?

Answer 1

All Java Objects extend the Object class. So you can make your function accept an Object array:

public void func(Object[] args) {
}

Or if you want to be able to pass nothing:

public void func(Object... args) {
}

Answer 2

public void omnivore(Object... args) {
   // what now?
}

In Java, a variable of any reference type (objects and arrays), including ones of some generic type, even wildcards, can be passed to a parameter of type Object. A variable of any primitive type can be autoboxed to its corresponding wrapper type, which is a reference type, and so can be passed as Object. So, Object... will accept any number of anything.

Answer 3

Use this syntax:

void myMethod(Object... args) {
    // Here, args is an array of java.lang.Object:
    // you can take its length, get its elements with [i] operator,
    // and so on.
}

Answer 4

The closest you will get is someMethod(Object ... args) .

Strictly, this does not accept all argument types. Specifically, it does not accept primitive types: these need boxed to the corresponding wrapper types. Normally this makes no difference. But it does if you need to distinguish between primitive and wrapper types in the called method.