Re: Method calling

From:

Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 29 Jul 2008 16:48:56 -0700

Message-ID:

<488fac26$0$3375$7836cce5@newsrazor.net>

gaijinco wrote:

Is there a way in Java to call a method by having its name on a
string?

something as:

void foo(){}
void bar(){}

void callFunction(String s)
{
// Call function s
}

void otherFunction()
{
callFunction("foo");
}

Thanks.

The real question is why?

The technique you want is called reflection. It is often better to not
use reflection, unless you have a "Damned Good Reason".
<http://virtualinfinity.net/wordpress/program-design/2007/01/11/the-dangers-of-reflection-or-put-down-that-mirror/>

That being said. You can do something like:
myClass.class.getMethod("foo").invoke(this);

Instead of using "by name", you might think about using a pattern like:

void foo() {}
void bar() {}

void callFunction(Runnable r) { r.run(); }

void otherFunction() {
callFunction(new Runnable() { public void run() { foo(); } });
}

Yes, this is a little more typing, but the benefit is that you *can't*
misspell "foo" (the compiler wouldn't let you). There may be even
better ways to solve your real problem. What is your real goal?

--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>