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/*
* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* @test
* @bug 8003280
* @summary Add lambda tests
* Test method reference with SAM interface Comparator<T>
* @compile MethodRef5.java
* @run main MethodRef5
*/
import java.util.Collections;
import java.util.List;
import java.util.ArrayList;
public class MethodRef5 {
static class Person {
private String firstName;
private String lastName;
private int age;
public Person() { }
public Person(String fn, String ln, int a) {
firstName = fn;
lastName = ln;
age = a;
}
public String getLastName() {
return lastName;
}
public int getAge() {
return age;
}
//the following 2 methods are signature-compatible with Comparator<Person>.compare():
public static int compareByAge(Person a, Person b) {
return a.age - b.age;
}
public int compareByLastName(Person a, Person b) {
return a.lastName.compareToIgnoreCase(b.lastName);
}
}
private static void assertTrue(boolean cond) {
if (!cond)
throw new AssertionError();
}
public static void main(String[] args) {
List<Person> persons = new ArrayList<Person>();
persons.add(new Person("John", "Smith", 49));
persons.add(new Person("Abraham", "Lincoln", 30));
persons.add(new Person("George", "Washington", 29));
persons.add(new Person("Peter", "Derby", 50));
Collections.sort(persons, Person::compareByAge);//static method reference to compareByAge(Person, Person)
String age = "";
for (Person p : persons) {
age += p.getAge() + " ";
}
assertTrue( (age.equals("29 30 49 50 ")) );
Collections.sort(persons, new Person()::compareByLastName);//instance method reference to compareByLastName(Person, Person)
String lastName = "";
for (Person p : persons) {
lastName += p.getLastName() + " ";
}
assertTrue( lastName.equals("Derby Lincoln Smith Washington ") );
}
}
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