[ACCEPTED]-In groovy, is there a way to check if an object has a given method?-groovy
Accepted answer
Use respondsTo
class Foo {
String prop
def bar() { "bar" }
def bar(String name) { "bar $name" }
}
def f = new Foo()
// Does f have a no-arg bar method
if (f.metaClass.respondsTo(f, "bar")) {
// do stuff
}
// Does f have a bar method that takes a String param
if (f.metaClass.respondsTo(f, "bar", String)) {
// do stuff
}
0
Just implement methodMissing in your class:
class Foo {
def methodMissing(String name, args) { return null; }
}
And 4 then, every time you try to invoke a method 3 that doesn't exist, you will get a null 2 value.
def foo = new Foo();
assert foo.someMethod(), null
For more information, take a look 1 here: http://groovy.codehaus.org/Using+methodMissing+and+propertyMissing
You should be able to do something like:
SomeObj.metaClass.getMetaMethod("someMethod")
Or 2 you can fall back to the good old Java reflection 1 API.
You can achieve this by using getMetaMethod together 1 with the safe navigation operator ?.:
def str = "foo"
def num = 42
def methodName = "length"
def args = [] as Object[]
assert 3 == str.metaClass.getMetaMethod(methodName, args)?.invoke(str, args);
assert null == num.metaClass.getMetaMethod(methodName, args)?.invoke(num, args);
if class :
MyClass.metaClass.methods*.name.any{it=='myMethod'}//true if exist
if object :
myObj.class.metaClass.methods*.name.any{it=='myMethod'}//true if exist
0
Source:
stackoverflow.com
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