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Java example source code file (JDKBridge.java)

This example Java source code file (JDKBridge.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

class, classloader, classnotfoundexception, corba, getpropertyaction, jdkbridge, local_codebase_key, malformedurlexception, net, network, rmi, security, string, use_codebase_only_key, util

The JDKBridge.java Java example source code

/*
 * Copyright (c) 1995, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.
 */
/*
 * Licensed Materials - Property of IBM
 * RMI-IIOP v1.0
 * Copyright IBM Corp. 1998 1999  All Rights Reserved
 *
 */

package com.sun.corba.se.impl.util;

import java.rmi.Remote;
import java.rmi.NoSuchObjectException;
import java.rmi.server.RMIClassLoader;
import java.rmi.server.UnicastRemoteObject;
import org.omg.CORBA.BAD_PARAM;
import org.omg.CORBA.CompletionStatus;
import java.util.Properties;
import java.io.File;
import java.io.FileInputStream;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.net.MalformedURLException;
import com.sun.corba.se.impl.orbutil.GetPropertyAction;

/**
 *  Utility methods for doing various method calls which are used
 *  by multiple classes
 */
public class JDKBridge {

    /**
     * Get local codebase System property (java.rmi.server.codebase).
     * May be null or a space separated array of URLS.
     */
    public static String getLocalCodebase () {
        return localCodebase;
    }

    /**
     * Return true if the system property "java.rmi.server.useCodebaseOnly"
     * is set, false otherwise.
     */
    public static boolean useCodebaseOnly () {
        return useCodebaseOnly;
    }

    /**
     * Returns a class instance for the specified class.
     * @param className the name of the class
     * @param remoteCodebase a space-separated array of urls at which
     * the class might be found. May be null.
     * @param loader a ClassLoader who may be used to
     * load the class if all other methods fail.
     * @return the <code>Class object representing the loaded class.
     * @exception throws ClassNotFoundException if class cannot be loaded.
     */
    public static Class loadClass (String className,
                                   String remoteCodebase,
                                   ClassLoader loader)
        throws ClassNotFoundException {

        if (loader == null) {
            return loadClassM(className,remoteCodebase,useCodebaseOnly);
        } else {
            try {
                return loadClassM(className,remoteCodebase,useCodebaseOnly);
            } catch (ClassNotFoundException e) {
                return loader.loadClass(className);
            }
        }
    }

    /**
     * Returns a class instance for the specified class.
     * @param className the name of the class
     * @param remoteCodebase a space-separated array of urls at which
     * the class might be found. May be null.
     * @return the <code>Class object representing the loaded class.
     * @exception throws ClassNotFoundException if class cannot be loaded.
     */
    public static Class loadClass (String className,
                                   String remoteCodebase)
        throws ClassNotFoundException {
        return loadClass(className,remoteCodebase,null);
    }

    /**
     * Returns a class instance for the specified class.
     * @param className the name of the class
     * @return the <code>Class object representing the loaded class.
     * @exception throws ClassNotFoundException if class cannot be loaded.
     */
    public static Class loadClass (String className)
        throws ClassNotFoundException {
        return loadClass(className,null,null);
    }

    private static final String LOCAL_CODEBASE_KEY = "java.rmi.server.codebase";
    private static final String USE_CODEBASE_ONLY_KEY = "java.rmi.server.useCodebaseOnly";
    private static String localCodebase = null;
    private static boolean useCodebaseOnly;

    static {
        setCodebaseProperties();
    }

    public static final void main (String[] args) {
        System.out.println("1.2 VM");

        /*
                 // If on 1.2, use a policy with all permissions.
                 System.setSecurityManager (new javax.rmi.download.SecurityManager());
                 String targetClass = "[[Lrmic.Typedef;";
                 System.out.println("localCodebase =  "+localCodebase);
                 System.out.println("Trying to load "+targetClass);
                 try {
                 Class clz = loadClass(targetClass,null,localCodebase);
                 System.out.println("Loaded: "+clz);
                 } catch (ClassNotFoundException e) {
                 System.out.println("Caught "+e);
                 }
        */
    }

    /**
     * Set the codebase and useCodebaseOnly properties. This is public
     * only for test code.
     */
    public static synchronized void setCodebaseProperties () {
        String prop = (String)AccessController.doPrivileged(
            new GetPropertyAction(LOCAL_CODEBASE_KEY)
        );
        if (prop != null && prop.trim().length() > 0) {
            localCodebase = prop;
        }

        prop = (String)AccessController.doPrivileged(
            new GetPropertyAction(USE_CODEBASE_ONLY_KEY)
        );
        if (prop != null && prop.trim().length() > 0) {
            useCodebaseOnly = Boolean.valueOf(prop).booleanValue();
        }
    }

    /**
     * Set the default code base. This method is here only
     * for test code.
     */
    public static synchronized void setLocalCodebase(String codebase) {
        localCodebase = codebase;
    }

    private static Class loadClassM (String className,
                            String remoteCodebase,
                            boolean useCodebaseOnly)
        throws ClassNotFoundException {

        try {
            return JDKClassLoader.loadClass(null,className);
        } catch (ClassNotFoundException e) {}
        try {
            if (!useCodebaseOnly && remoteCodebase != null) {
                return RMIClassLoader.loadClass(remoteCodebase,
                                                className);
            } else {
                return RMIClassLoader.loadClass(className);
            }
        } catch (MalformedURLException e) {
            className = className + ": " + e.toString();
        }

        throw new ClassNotFoundException(className);
    }
}

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