24、map findAll

class GroovyTest {

    static void main(args) {

        def people = [
                1: [name: 'Bob', age: 32, gender: 'M'],
                2: [name: 'Johnny', age: 36, gender: 'M'],
                3: [name: 'Claire', age: 21, gender: 'F'],
                4: [name: 'Amy', age: 54, gender: 'F']
        ]
        def females = people.findAll{it.value.gender == 'F'}
        print females

    }
}

输出：

[3:[name:Claire, age:21, gender:F], 4:[name:Amy, age:54, gender:F]]