1/*
2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
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22 */
23
24/**
25 * @test
26 * @bug 8003280
27 * @summary Add lambda tests
28 *   Test method reference with SAM interface Comparator<T>
29 * @compile MethodRef5.java
30 * @run main MethodRef5
31 */
32
33import java.util.Collections;
34import java.util.List;
35import java.util.ArrayList;
36
37public class MethodRef5 {
38
39    static class Person {
40
41        private String firstName;
42        private String lastName;
43        private int age;
44
45        public Person() { }
46
47        public Person(String fn, String ln, int a) {
48            firstName = fn;
49            lastName = ln;
50            age = a;
51        }
52
53        public String getLastName() {
54            return lastName;
55        }
56
57        public int getAge() {
58            return age;
59        }
60
61        //the following 2 methods are signature-compatible with Comparator<Person>.compare():
62        public static int compareByAge(Person a, Person b) {
63            return a.age - b.age;
64        }
65
66        public int compareByLastName(Person a, Person b) {
67            return a.lastName.compareToIgnoreCase(b.lastName);
68        }
69    }
70
71    private static void assertTrue(boolean cond) {
72        if (!cond)
73            throw new AssertionError();
74    }
75
76    public static void main(String[] args) {
77
78        List<Person> persons = new ArrayList<Person>();
79        persons.add(new Person("John", "Smith", 49));
80        persons.add(new Person("Abraham", "Lincoln", 30));
81        persons.add(new Person("George", "Washington", 29));
82        persons.add(new Person("Peter", "Derby", 50));
83        Collections.sort(persons, Person::compareByAge);//static method reference to compareByAge(Person, Person)
84        String age = "";
85        for (Person p : persons) {
86            age += p.getAge() + " ";
87        }
88        assertTrue( (age.equals("29 30 49 50 ")) );
89        Collections.sort(persons, new Person()::compareByLastName);//instance method reference to compareByLastName(Person, Person)
90        String lastName = "";
91        for (Person p : persons) {
92            lastName += p.getLastName() + " ";
93        }
94        assertTrue( lastName.equals("Derby Lincoln Smith Washington ") );
95    }
96}
97