Java example source code file (Test4508780.java)

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Java - Java tags/keywords

bean, bean2, bean3, bean4, class, classloader, error, exception, javabean, method, object, propertydescriptor, reflection, runnable, simpleclassloader, string, test4508780

The Test4508780.java Java example source code

/*
 * Copyright (c) 2003, 2007, 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 4508780
 * @summary Tests shared access to the Introspector cache
 * @author Mark Davidson
 */

import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;

import java.lang.reflect.Method;

/**
 * Multiple classloader test to ensure that methods
 * returned by the BeanInfo classes are unique to the classloader.
 */
public class Test4508780 implements Runnable {
    /**
     * This is here to force the bean classes to be compiled
     */
    private static final Class[] COMPILE = {
            Bean.class,
            Bean2.class,
            Bean3.class,
            Bean4.class,
    };

    public static void main(String[] args) {
        for (int i = 0; i < 10; i++) test();
    }

    private static void test() {
        test("Bean", "Bean2", "Bean3", "Bean4");
        test("Bean4", "Bean", "Bean2", "Bean3");
        test("Bean3", "Bean4", "Bean", "Bean2");
        test("Bean2", "Bean3", "Bean4", "Bean");
        Introspector.flushCaches();
    }

    private static void test(String... names) {
        new Thread(new Test4508780(names)).start();
    }

    private final ClassLoader loader = new SimpleClassLoader();
    private final String[] names;

    private Test4508780(String... names) {
        this.names = names;
    }

    public void run() {
        for (String name : this.names) {
            Object bean;
            try {
                bean = this.loader.loadClass(name).newInstance();
            } catch (Exception exception) {
                throw new Error("could not instantiate bean: " + name, exception);
            }
            if (this.loader != bean.getClass().getClassLoader()) {
                throw new Error("bean class loader is not equal to default one");
            }
            PropertyDescriptor[] pds = getPropertyDescriptors(bean);
            for (PropertyDescriptor pd : pds) {
                Class type = pd.getPropertyType();
                Method setter = pd.getWriteMethod();
                Method getter = pd.getReadMethod();

                if (type.equals(String.class)) {
                    executeMethod(setter, bean, "Foo");
                } else if (type.equals(int.class)) {
                    executeMethod(setter, bean, Integer.valueOf(1));
                }
                executeMethod(getter, bean);
            }
        }
    }

    private static void executeMethod(Method method, Object bean, Object... args) {
        if (method == null) {
            throw new Error("method is null");
        }
        if (bean == null) {
            throw new Error("target bean is null");
        }
        try {
            method.invoke(bean, args);
        } catch (Exception exception) {
            throw new Error("could not execute method: " + method, exception);
        }
    }

    private static PropertyDescriptor[] getPropertyDescriptors(Object object) {
        Class type = object.getClass();
        synchronized (System.out) {
            System.out.println(type);
            ClassLoader loader = type.getClassLoader();
            while (loader != null) {
                System.out.println(" - loader: " + loader);
                loader = loader.getParent();
            }
        }
        try {
            return Introspector.getBeanInfo(type).getPropertyDescriptors();
        } catch (IntrospectionException exception) {
            throw new Error("unexpected exception", exception);
        }
    }
}