Generic method in Groovy [duplicate]

Question

I'm currently learning Groovy and I got stuck with generic methods.

I'd like to define generic method with generic return type that is inferred from argument type.

In Java the signature would be:

<T> T getBean(String name, Class<T> requiredType);

How can I achieve it in Groovy?

Answer 1

This works in Groovy 2.2.1:

class MyCollection {
    def map

    public <T> void setMap(Map<String,T> map) {
        this.map = map
    }

    public <T> T getBean(String name, Class<T> requiredType) {
        return map.get(name)
    }
}

def myc = new MyCollection()
Map<String,Integer> myMap = new HashMap<String,Integer>()
myMap.put("abc",123)
myMap.put("ijk",456)
myc.setMap(myMap)

assert 123 == myc.getBean("abc", Integer.class)
assert 456 == myc.getBean("ijk", Integer.class)

Note that the method is public. If the method is written as "package protected", it won't compile for me.

However, this edit works for package scope:

import groovy.transform.PackageScope

class MyCollection {
    // snip

    @PackageScope <T> T getBean(String name, Class<T> requiredType) {