Java example source code file (EnclosingClassTest.java)

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Java - Java tags/keywords

assertionerror, class, enclosingclass, enclosingclasstest, field, illegalaccessexception, reflection, runtimeexception, string, testme, util

The EnclosingClassTest.java Java example source code

/*
 * Copyright (c) 2004, 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 4992173 4992170
 *
 * @run shell make_src.sh
 * @run shell build.sh
 * @run main/othervm -esa -ea EnclosingClassTest
 *
 * @summary Check getEnclosingClass and other methods
 * @author Peter von der Ah\u00e9
 */

/*
 * We have five kinds of classes:
 * a) Top level classes
 * b) Nested classes (static member classes)
 * c) Inner classes (non-static member classes)
 * d) Local classes (named classes declared within a method)
 * e) Anonymous classes
 *
 * Each one can be within a package or not.
 * Kinds b-e can/must be within kinds a-e.
 * This gives us a three dimensional space:
 * 1. dimension: b-e
 * 2. dimension: a-e
 * 3. dimension: packages
 *
 * We make a two dimensional matrix of (b-e)x(a-e) and change the
 * package configuration on that:
 *
 *   b c d e
 * a x x x x
 * b x x x x
 * c o x x x  where o means "not legal"
 * d o x x x
 * e o x x x
 */

import java.util.List;
import java.util.LinkedList;
import java.lang.reflect.Field;
import common.TestMe;

public class EnclosingClassTest {
    static void info(Class<?> c, Class encClass, String desc) {
        if (!"".equals(desc))
            System.out.println(desc + ":");
        System.out.println(c);
        System.out.println("\tis enclosed by:\t\t" + encClass);
        System.out.println("\thas simple name:\t`" +
                           c.getSimpleName() + "'");
        System.out.println("\thas canonical name:\t`" +
                           c.getCanonicalName() + "'");
    }

    static void match(String actual, String expected) {
        assert((actual == null && expected == null) || actual.equals(expected));
        System.out.println("\t`" +
                           actual + "' matches expected `" +
                           expected + "'");
    }

    static void check(Class<?> c, Class enc,
                      String encName, String encNameExpected,
                      String simpleName, String simpleNameExpected,
                      String canonicalName, String canonicalNameExpected) {
        match(encName, encNameExpected);
        match(simpleName, simpleNameExpected);
        match(canonicalName, canonicalNameExpected);
    }

    static void testClass(Class<?> c, TestMe annotation, Field f) {
        if (Void.class.equals(c))
            return;
        Class<?> encClass = c.getEnclosingClass();
        c.getEnclosingMethod(); // make sure it does not crash
        c.getEnclosingConstructor(); // make sure it does not crash
        info(c, encClass, annotation.desc());
        check(c, encClass,
              ""+encClass, annotation.encl(),
              c.getSimpleName(), annotation.simple(),
              c.getCanonicalName(),
              annotation.hasCanonical() ? annotation.canonical() : null);
        if (void.class.equals(c))
            return;
        Class<?> array = java.lang.reflect.Array.newInstance(c, 0).getClass();
        check(array, array.getEnclosingClass(),
              "", "",
              array.getSimpleName(), annotation.simple()+"[]",
              array.getCanonicalName(),
              annotation.hasCanonical() ? annotation.canonical()+"[]" : null);
    }

    static void test(Object tests) {
        for (Field f : tests.getClass().getFields()) {
            TestMe annotation = f.getAnnotation(TestMe.class);
            if (annotation != null) {
                try {
                    testClass((Class<?>)f.get(tests), annotation, f);
                } catch (AssertionError ex) {
                    System.err.println("Error in " +
                                       tests.getClass().getName() +
                                       "." + f.getName());
                    throw ex;
                } catch (IllegalAccessException ex) {
                    ex.printStackTrace();
                    throw new RuntimeException(ex);
                }
            }
        }
    }
    public static void main(String[] args) {
        test(new EnclosingClass());
        test(new pkg1.EnclosingClass());
        test(new pkg1.pkg2.EnclosingClass());
    }
}