Java example source code file (TypeParameterMatcherTest.java)

This example Java source code file (TypeParameterMatcherTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

aaa, bbb, exception, object, test, typeparametermatcher, typeq, util

The TypeParameterMatcherTest.java Java example source code

/*
 * Copyright 2013 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package io.netty.util.internal;

import org.junit.Test;

import java.util.Date;

import static org.junit.Assert.*;

public class TypeParameterMatcherTest {

    @Test
    public void testConcreteClass() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new TypeQ(), TypeX.class, "A");
        assertFalse(m.match(new Object()));
        assertFalse(m.match(new A()));
        assertFalse(m.match(new AA()));
        assertTrue(m.match(new AAA()));
        assertFalse(m.match(new B()));
        assertFalse(m.match(new BB()));
        assertFalse(m.match(new BBB()));
        assertFalse(m.match(new C()));
        assertFalse(m.match(new CC()));
    }

    @Test(expected = IllegalStateException.class)
    public void testUnsolvedParameter() throws Exception {
        TypeParameterMatcher.find(new TypeQ(), TypeX.class, "B");
    }

    @Test
    public void testAnonymousClass() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new TypeQ<BBB>() { }, TypeX.class, "B");
        assertFalse(m.match(new Object()));
        assertFalse(m.match(new A()));
        assertFalse(m.match(new AA()));
        assertFalse(m.match(new AAA()));
        assertFalse(m.match(new B()));
        assertFalse(m.match(new BB()));
        assertTrue(m.match(new BBB()));
        assertFalse(m.match(new C()));
        assertFalse(m.match(new CC()));
    }

    @Test
    public void testAbstractClass() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new TypeQ(), TypeX.class, "C");
        assertFalse(m.match(new Object()));
        assertFalse(m.match(new A()));
        assertFalse(m.match(new AA()));
        assertFalse(m.match(new AAA()));
        assertFalse(m.match(new B()));
        assertFalse(m.match(new BB()));
        assertFalse(m.match(new BBB()));
        assertFalse(m.match(new C()));
        assertTrue(m.match(new CC()));
    }

    public static class TypeX<A, B, C> {
        A a;
        B b;
        C c;
    }

    public static class TypeY<D extends C, E extends A, F extends B> extends TypeX { }

    public abstract static class TypeZ<G extends AA, H extends BB> extends TypeY { }

    public static class TypeQ<I extends BBB> extends TypeZ { }

    public static class A { }
    public static class AA extends A { }
    public static class AAA extends AA { }

    public static class B { }
    public static class BB extends B { }
    public static class BBB extends BB { }

    public static class C { }
    public static class CC extends C { }

    @Test
    public void testInaccessibleClass() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new U<T>() { }, U.class, "E");
        assertFalse(m.match(new Object()));
        assertTrue(m.match(new T()));
    }

    private static class T { }
    private static class U<E> { E a; }

    @Test
    public void testArrayAsTypeParam() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new U<byte[]>() { }, U.class, "E");
        assertFalse(m.match(new Object()));
        assertTrue(m.match(new byte[1]));
    }

    @Test
    public void testRawType() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new U() { }, U.class, "E");
        assertTrue(m.match(new Object()));
    }

    private static class V<E> {
        U<E> u = new U() { };
    }

    @Test
    public void testInnerClass() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new V<String>().u, U.class, "E");
        assertTrue(m.match(new Object()));
    }

    private abstract static class W<E> {
        E e;
    }

    private static class X<T, E> extends W {
        T t;
    }

    @Test(expected = IllegalStateException.class)
    public void testErasure() throws Exception {
        TypeParameterMatcher m = TypeParameterMatcher.find(new X<String, Date>(), W.class, "E");
        assertTrue(m.match(new Date()));
        assertFalse(m.match(new Object()));
    }
}