Java example source code file (PostExceptionTest.java)

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Java - Java tags/keywords

case, create, enumset, error, exception, exceptionalwombat, expected, management, mbeanserver, net, network, objectinstance, objectname, runtimeexception, runtimembeanexception, throwable, util, where

The PostExceptionTest.java Java example source code

/*
 * Copyright (c) 2008, 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 6730926
 * @summary Check behaviour of MBeanServer when postRegister and postDeregister
 *          throw exceptions.
 * @author Daniel Fuchs
 * @compile PostExceptionTest.java
 * @run main PostExceptionTest
 */

import javax.management.*;
import java.io.Serializable;
import java.net.URL;
import java.util.EnumSet;
import javax.management.loading.MLet;

public class PostExceptionTest {

    /**
     * A test case where we instantiate an ExceptionalWombatMBean (or a
     * subclass of it) which will throw the exception {@code t} from within
     * the methods indicated by {@code where}
     */
    public static class Case {
        public final Throwable t;
        public final EnumSet<WHERE> where;
        public Case(Throwable t,EnumSet<WHERE> where) {
            this.t=t; this.where=where;
        }
    }

    // Various methods to create an instance of Case in a single line
    // --------------------------------------------------------------

    public static Case caze(Throwable t, WHERE w) {
        return new Case(t,EnumSet.of(w));
    }
    public static Case caze(Throwable t, EnumSet<WHERE> where) {
        return new Case(t,where);
    }
    public static Case caze(Throwable t, WHERE w, WHERE... rest) {
        return new Case(t,EnumSet.of(w,rest));
    }

    /**
     * Here is the list of our test cases:
     */
    public static Case[] cases ={
        caze(new RuntimeException(),WHERE.PREREGISTER),
        caze(new RuntimeException(),WHERE.POSTREGISTER),
        caze(new RuntimeException(),WHERE.POSTREGISTER, WHERE.PREDEREGISTER),
        caze(new RuntimeException(),WHERE.POSTREGISTER, WHERE.POSTDEREGISTER),
        caze(new Exception(),WHERE.PREREGISTER),
        caze(new Exception(),WHERE.POSTREGISTER),
        caze(new Exception(),WHERE.POSTREGISTER, WHERE.PREDEREGISTER),
        caze(new Exception(),WHERE.POSTREGISTER, WHERE.POSTDEREGISTER),
        caze(new Error(),WHERE.PREREGISTER),
        caze(new Error(),WHERE.POSTREGISTER),
        caze(new Error(),WHERE.POSTREGISTER, WHERE.PREDEREGISTER),
        caze(new Error(),WHERE.POSTREGISTER, WHERE.POSTDEREGISTER),
        caze(new RuntimeException(),EnumSet.allOf(WHERE.class)),
        caze(new Exception(),EnumSet.allOf(WHERE.class)),
        caze(new Error(),EnumSet.allOf(WHERE.class)),
    };

    public static void main(String[] args) throws Exception {
        System.out.println("Test behaviour of MBeanServer when postRegister " +
                "or postDeregister throw exceptions");
        MBeanServer mbs = MBeanServerFactory.newMBeanServer();
        int failures = 0;
        final ObjectName n = new ObjectName("test:type=Wombat");

        // We're going to test each cases, using each of the 4 createMBean
        // forms + registerMBean in turn to create the MBean.
        // Wich method is used to create the MBean is indicated by "how"
        //
        for (Case caze:cases) {
            for (CREATE how : CREATE.values()) {
                failures+=test(mbs,n,how,caze.t,caze.where);
            }
        }
        if (failures == 0)
            System.out.println("Test passed");
        else {
            System.out.println("TEST FAILED: " + failures + " failure(s)");
            System.exit(1);
        }
    }

    // Execute a test case composed of:
    // mbs:   The MBeanServer where the MBean will be registered,
    // name:  The name of that MBean
    // how:   How will the MBean be created/registered (which MBeanServer
    //        method)
    // t:     The exception/error that the MBean will throw
    // where: In which pre/post register/deregister method the exception/error
    //        will be thrown
    //
    private static int test(MBeanServer mbs, ObjectName name, CREATE how,
            Throwable t, EnumSet<WHERE> where)
            throws Exception {
        System.out.println("-------<"+how+"> / <"+t+"> / "+ where + "-------");

        int failures = 0;
        ObjectInstance oi = null;
        Exception reg = null;    // exception thrown by create/register
        Exception unreg = null;  // exception thrown by unregister
        try {
            // Create the MBean
            oi = how.create(t, where, mbs, name);
        } catch (Exception xx) {
            reg=xx;
        }
        final ObjectName n = (oi==null)?name:oi.getObjectName();
        final boolean isRegistered = mbs.isRegistered(n);
        try {
            // If the MBean is registered, unregister it
            if (isRegistered) mbs.unregisterMBean(n);
        } catch (Exception xxx) {
            unreg=xxx;
        }
        final boolean isUnregistered = !mbs.isRegistered(n);
        if (!isUnregistered) {
            // if the MBean is still registered (preDeregister threw an
            // exception) signify to the MBean that it now should stop
            // throwing anaything and unregister it.
            JMX.newMBeanProxy(mbs, n, ExceptionalWombatMBean.class).end();
            mbs.unregisterMBean(n);
        }

        // Now analyze the result. If we didn't ask the MBean to throw any
        // exception then reg should be null.
        if (where.isEmpty() && reg!=null) {
            System.out.println("Unexpected registration exception: "+
                    reg);
            throw new RuntimeException("Unexpected registration exception: "+
                    reg,reg);
        }

        // If we didn't ask the MBean to throw any exception then unreg should
        // also be null.
        if (where.isEmpty() && unreg!=null) {
            System.out.println("Unexpected unregistration exception: "+
                    unreg);
            throw new RuntimeException("Unexpected unregistration exception: "+
                    unreg,unreg);
        }

        // If we asked the MBean to throw an exception in either of preRegister
        // or postRegister, then reg should not be null.
        if ((where.contains(WHERE.PREREGISTER)
            || where.contains(WHERE.POSTREGISTER))&& reg==null) {
            System.out.println("Expected registration exception not " +
                    "thrown by "+where);
            throw new RuntimeException("Expected registration exception not " +
                    "thrown by "+where);
        }

        // If we asked the MBean not to throw any exception in preRegister
        // then the MBean should have been registered, unregisterMBean should
        // have been called.
        // If we asked the MBean to throw an exception in either of preDeregister
        // or postDeregister, then unreg should not be null.
        if ((where.contains(WHERE.PREDEREGISTER)
            || where.contains(WHERE.POSTDEREGISTER))&& unreg==null
            && !where.contains(WHERE.PREREGISTER)) {
            System.out.println("Expected unregistration exception not " +
                    "thrown by "+where);
            throw new RuntimeException("Expected unregistration exception not " +
                    "thrown by "+where);
        }

        // If we asked the MBean to throw an exception in preRegister
        // then the MBean should not have been registered.
        if (where.contains(WHERE.PREREGISTER)) {
            if (isRegistered) {
                System.out.println("MBean is still registered [" +
                        where+
                        "]: "+name+" / "+reg);
                throw new RuntimeException("MBean is still registered [" +
                        where+
                        "]: "+name+" / "+reg,reg);
            }
        }

        // If we asked the MBean not to throw an exception in preRegister,
        // but to throw an exception in postRegister, then the MBean should
        // have been registered.
        if (where.contains(WHERE.POSTREGISTER) &&
                !where.contains(WHERE.PREREGISTER)) {
            if (!isRegistered) {
                System.out.println("MBean is already unregistered [" +
                        where+
                        "]: "+name+" / "+reg);
                throw new RuntimeException("MBean is already unregistered [" +
                        where+
                        "]: "+name+" / "+reg,reg);
            }
        }

        // If we asked the MBean to throw an exception in preRegister,
        // check that the exception we caught was as expected.
        //
        if (where.contains(WHERE.PREREGISTER)) {
            WHERE.PREREGISTER.check(reg, t);
        } else if (where.contains(WHERE.POSTREGISTER)) {
            // If we asked the MBean to throw an exception in postRegister,
            // check that the exception we caught was as expected.
            // We don't do this check if we asked the MBean to also throw an
            // exception in pre register, because postRegister will not have
            // been called.
            WHERE.POSTREGISTER.check(reg, t);
        }

        if (!isRegistered) return failures;

        // The MBean was registered, so unregisterMBean was called. Check
        // unregisterMBean exceptions...
        //

        // If we asked the MBean to throw an exception in preDeregister
        // then the MBean should not have been deregistered.
        if (where.contains(WHERE.PREDEREGISTER)) {
            if (isUnregistered) {
                System.out.println("MBean is already unregistered [" +
                        where+
                        "]: "+name+" / "+unreg);
                throw new RuntimeException("MBean is already unregistered [" +
                        where+
                        "]: "+name+" / "+unreg,unreg);
            }
        }

        // If we asked the MBean not to throw an exception in preDeregister,
        // but to throw an exception in postDeregister, then the MBean should
        // have been deregistered.
        if (where.contains(WHERE.POSTDEREGISTER) &&
                !where.contains(WHERE.PREDEREGISTER)) {
            if (!isUnregistered) {
                System.out.println("MBean is not unregistered [" +
                        where+
                        "]: "+name+" / "+unreg);
                throw new RuntimeException("MBean is not unregistered [" +
                        where+
                        "]: "+name+" / "+unreg,unreg);
            }
        }

        // If we asked the MBean to throw an exception in preDeregister,
        // check that the exception we caught was as expected.
        //
        if (where.contains(WHERE.PREDEREGISTER)) {
            WHERE.PREDEREGISTER.check(unreg, t);
        } else if (where.contains(WHERE.POSTDEREGISTER)) {
            // If we asked the MBean to throw an exception in postDeregister,
            // check that the exception we caught was as expected.
            // We don't do this check if we asked the MBean to also throw an
            // exception in pre register, because postRegister will not have
            // been called.
            WHERE.POSTDEREGISTER.check(unreg, t);
        }
        return failures;
    }

    /**
     * This enum lists the 4 methods in MBeanRegistration.
     */
    public static enum WHERE {

        PREREGISTER, POSTREGISTER, PREDEREGISTER, POSTDEREGISTER;

        // Checks that an exception thrown by the MBeanServer correspond to
        // what is expected when an MBean throws an exception in this
        // MBeanRegistration method ("this" is one of the 4 enum values above)
        //
        public void check(Exception thrown, Throwable t)
                throws Exception {
           if (t instanceof RuntimeException) {
               if (!(thrown instanceof RuntimeMBeanException)) {
                   System.out.println("Expected RuntimeMBeanException, got "+
                           thrown);
                   throw new Exception("Expected RuntimeMBeanException, got "+
                           thrown);
               }
           } else if (t instanceof Error) {
               if (!(thrown instanceof RuntimeErrorException)) {
                   System.out.println("Expected RuntimeErrorException, got "+
                           thrown);
                   throw new Exception("Expected RuntimeErrorException, got "+
                           thrown);
               }
           } else if (t instanceof Exception) {
               if (EnumSet.of(POSTDEREGISTER,POSTREGISTER).contains(this)) {
                   if (!(thrown instanceof RuntimeMBeanException)) {
                       System.out.println("Expected RuntimeMBeanException, got "+
                           thrown);
                       throw new Exception("Expected RuntimeMBeanException, got "+
                           thrown);
                   }
                   if (! (thrown.getCause() instanceof RuntimeException)) {
                       System.out.println("Bad cause: " +
                               "expected RuntimeException, " +
                           "got <"+thrown.getCause()+">");
                       throw new Exception("Bad cause: " +
                               "expected RuntimeException, " +
                           "got <"+thrown.getCause()+">");
                   }
               }
               if (EnumSet.of(PREDEREGISTER,PREREGISTER).contains(this)) {
                   if (!(thrown instanceof MBeanRegistrationException)) {
                       System.out.println("Expected " +
                               "MBeanRegistrationException, got "+
                           thrown);
                       throw new Exception("Expected " +
                               "MBeanRegistrationException, got "+
                           thrown);
                   }
                   if (! (thrown.getCause() instanceof Exception)) {
                       System.out.println("Bad cause: " +
                               "expected Exception, " +
                           "got <"+thrown.getCause()+">");
                       throw new Exception("Bad cause: " +
                               "expected Exception, " +
                           "got <"+thrown.getCause()+">");
                   }
               }
           }

        }
    }

    /**
     * This enum lists the 5 methods to create and register an
     * ExceptionalWombat MBean
     */
    public static enum CREATE {

        CREATE1() {
            // Creates an ExceptionalWombat MBean using createMBean form #1
            public ObjectInstance create(Throwable t, EnumSet<WHERE> where,
                    MBeanServer server, ObjectName name) throws Exception {
                ExceptionallyHackyWombat.t = t;
                ExceptionallyHackyWombat.w = where;
                return server.createMBean(
                        ExceptionallyHackyWombat.class.getName(),
                        name);
            }
        },
        CREATE2() {
            // Creates an ExceptionalWombat MBean using createMBean form #2
            public ObjectInstance create(Throwable t, EnumSet<WHERE> where,
                    MBeanServer server, ObjectName name) throws Exception {
                ExceptionallyHackyWombat.t = t;
                ExceptionallyHackyWombat.w = where;
                final ObjectName loaderName = registerMLet(server);
                return server.createMBean(
                        ExceptionallyHackyWombat.class.getName(),
                        name, loaderName);
            }
        },
        CREATE3() {
            // Creates an ExceptionalWombat MBean using createMBean form #3
            public ObjectInstance create(Throwable t, EnumSet<WHERE> where,
                    MBeanServer server, ObjectName name) throws Exception {
                final Object[] params = {t, where};
                final String[] signature = {Throwable.class.getName(),
                    EnumSet.class.getName()
                };
                return server.createMBean(
                        ExceptionalWombat.class.getName(), name,
                        params, signature);
            }
        },
        CREATE4() {
            // Creates an ExceptionalWombat MBean using createMBean form #4
            public ObjectInstance create(Throwable t, EnumSet<WHERE> where,
                    MBeanServer server, ObjectName name) throws Exception {
                final Object[] params = {t, where};
                final String[] signature = {Throwable.class.getName(),
                    EnumSet.class.getName()
                };
                return server.createMBean(
                        ExceptionalWombat.class.getName(), name,
                        registerMLet(server), params, signature);
            }
        },
        REGISTER() {
            // Creates an ExceptionalWombat MBean using registerMBean
            public ObjectInstance create(Throwable t, EnumSet<WHERE> where,
                    MBeanServer server, ObjectName name) throws Exception {
                final ExceptionalWombat wombat =
                        new ExceptionalWombat(t, where);
                return server.registerMBean(wombat, name);
            }
        };

        // Creates an ExceptionalWombat MBean using the method denoted by this
        // Enum value - one of CREATE1, CREATE2, CREATE3, CREATE4, or REGISTER.
        public abstract ObjectInstance create(Throwable t, EnumSet<WHERE> where,
                MBeanServer server, ObjectName name) throws Exception;

        // This is a bit of a hack - we use an MLet that delegates to the
        // System ClassLoader so that we can use createMBean form #2 and #3
        // while still using the same class loader (system).
        // This is necessary to make the ExceptionallyHackyWombatMBean work ;-)
        //
        public ObjectName registerMLet(MBeanServer server) throws Exception {
            final ObjectName name = new ObjectName("test:type=MLet");
            if (server.isRegistered(name)) {
                return name;
            }
            final MLet mlet = new MLet(new URL[0],
                    ClassLoader.getSystemClassLoader());
            return server.registerMBean(mlet, name).getObjectName();
        }
    }

    /**
     *A Wombat MBean that can throw exceptions or errors in any of the
     * MBeanRegistration methods.
     */
    public static interface ExceptionalWombatMBean {
        // Tells the MBean to stop throwing exceptions - we sometime
        // need to call this at the end of the test so that we can
        // actually unregister the MBean.
        public void end();
    }

    /**
     *A Wombat MBean that can throw exceptions or errors in any of the
     * MBeanRegistration methods.
     */
    public static class ExceptionalWombat
            implements ExceptionalWombatMBean, MBeanRegistration {

        private final Throwable throwable;
        private final EnumSet<WHERE> where;
        private volatile boolean end=false;

        public ExceptionalWombat(Throwable t, EnumSet<WHERE> where) {
            this.throwable=t; this.where=where;
        }
        private Exception doThrow() {
            if (throwable instanceof Error)
                throw (Error)throwable;
            if (throwable instanceof RuntimeException)
                throw (RuntimeException)throwable;
            return (Exception)throwable;
        }
        public ObjectName preRegister(MBeanServer server, ObjectName name)
                throws Exception {
            if (!end && where.contains(WHERE.PREREGISTER))
                throw doThrow();
            return name;
        }

        public void postRegister(Boolean registrationDone) {
            if (!end && where.contains(WHERE.POSTREGISTER))
                throw new RuntimeException(doThrow());
        }

        public void preDeregister() throws Exception {
            if (!end && where.contains(WHERE.PREDEREGISTER))
                throw doThrow();
        }

        public void postDeregister() {
            if (!end && where.contains(WHERE.POSTREGISTER))
                throw new RuntimeException(doThrow());
        }

        public void end() {
            this.end=true;
        }
    }

    /**
     * This is a big ugly hack to call createMBean form #1 and #2 - where
     * the empty constructor is used. Since we still want to supply parameters
     * to the ExceptionalWombat super class, we temporarily store these
     * parameter value in a static volatile before calling create MBean.
     * Of course this only works because our test is sequential and single
     * threaded, and nobody but our test uses this ExceptionallyHackyWombat.
     */
    public static class ExceptionallyHackyWombat extends ExceptionalWombat {
        public static volatile Throwable  t;
        public static volatile EnumSet<WHERE> w;
        public ExceptionallyHackyWombat() {
            super(t,w);
        }
    }

}