mbeanintrospector.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

/*
 * @(#)MBeanIntrospector.java	1.10 06/01/23
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.sun.jmx.mbeanserver;


import static com.sun.jmx.mbeanserver.Util.*;

import java.lang.ref.WeakReference;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.List;
import java.util.WeakHashMap;

import javax.management.Descriptor;
import javax.management.ImmutableDescriptor;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanConstructorInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanNotificationInfo;
import javax.management.MBeanOperationInfo;
import javax.management.NotCompliantMBeanException;
import javax.management.NotificationBroadcaster;
import javax.management.ReflectionException;

/**
 * An introspector for MBeans of a certain type.  There is one instance
 * of this class for Standard MBeans and one for MXBeans, characterized
 * by the two concrete subclasses of this abstract class.
 *
 * @param <M> the representation of methods for this kind of MBean:
 * Method for Standard MBeans, ConvertingMethod for MXBeans.
 *
 * @since 1.6
 */
/*
 * Using a type parameter <M> allows us to deal with the fact that
 * Method and ConvertingMethod have no useful common ancestor, on
 * which we could call getName, getGenericReturnType, etc.  A simpler approach
 * would be to wrap every Method in an object that does have a common
 * ancestor with ConvertingMethod.  But that would mean an extra object
 * for every Method in every Standard MBean interface.
 */
abstract class MBeanIntrospector<M> {
    static final class PerInterfaceMap<M>
            extends WeakHashMap<Class<?>, WeakReference<PerInterface<M>>> {}
    
    /** The map from interface to PerInterface for this type of MBean. */
    abstract PerInterfaceMap<M> getPerInterfaceMap();
    /**
     * The map from concrete implementation class and interface to
     * MBeanInfo for this type of MBean.
     */
    abstract MBeanInfoMap getMBeanInfoMap();
    
    /** Make an interface analyzer for this type of MBean. */
    abstract MBeanAnalyzer<M> getAnalyzer(Class<?> mbeanInterface)
    throws NotCompliantMBeanException;
    
    /** True if MBeans with this kind of introspector are MXBeans. */
    abstract boolean isMXBean();
    
    /** Find the M corresponding to the given Method. */
    abstract M mFrom(Method m);
    
    /** Get the name of this method. */
    abstract String getName(M m);
    
    /**
     * Get the return type of this method.  This is the return type
     * of a method in a Java interface, so for MXBeans it is the
     * declared Java type, not the mapped Open Type.
     */
    abstract Type getGenericReturnType(M m);
    
    /**
     * Get the parameter types of this method in the Java interface
     * it came from.
     */
    abstract Type[] getGenericParameterTypes(M m);
    
    /**
     * Get the signature of this method as a caller would have to supply
     * it in MBeanServer.invoke.  For MXBeans, the named types will be
     * the mapped Open Types for the parameters.
     */
    abstract String[] getSignature(M m);
    
    /**
     * Check that this method is valid.  For example, a method in an
     * MXBean interface is not valid if one of its parameters cannot be
     * mapped to an Open Type.
     */
    abstract void checkMethod(M m) throws IllegalArgumentException;
    
    /**
     * Invoke the method with the given target and arguments.
     *
     * @param cookie Additional information about the target.  For an
     * MXBean, this is the MXBeanLookup associated with the MXBean.
     */
    /*
     * It would be cleaner if the type of the cookie were a
     * type parameter to this class, but that would involve a lot of
     * messy type parameter propagation just to avoid a couple of casts.
     */
    abstract Object invokeM2(M m, Object target, Object[] args, Object cookie)
    throws InvocationTargetException, IllegalAccessException,
            MBeanException;
    
    /**
     * Test whether the given value is valid for the given parameter of this
     * M.
     */
    abstract boolean validParameter(M m, Object value, int paramNo,
            Object cookie);
    
    /**
     * Construct an MBeanAttributeInfo for the given attribute based on the
     * given getter and setter.  One but not both of the getter and setter
     * may be null.
     */
    abstract MBeanAttributeInfo getMBeanAttributeInfo(String attributeName,
            M getter, M setter);
    /**
     * Construct an MBeanOperationInfo for the given operation based on
     * the M it was derived from.
     */
    abstract MBeanOperationInfo getMBeanOperationInfo(String operationName,
            M operation);
    
    /**
     * Get a Descriptor containing fields that MBeans of this kind will
     * always have.  For example, MXBeans will always have "mxbean=true".
     */
    abstract Descriptor getBasicMBeanDescriptor();
    
    /**
     * Get a Descriptor containing additional fields beyond the ones
     * from getBasicMBeanDescriptor that MBeans whose concrete class
     * is resourceClass will always have.
     */
    abstract Descriptor getMBeanDescriptor(Class<?> resourceClass);
    
    
    final PerInterface<M> getPerInterface(Class<?> mbeanInterface)
    throws NotCompliantMBeanException {
        PerInterfaceMap<M> map = getPerInterfaceMap();
        synchronized (map) {
            WeakReference<PerInterface<M>> wr = map.get(mbeanInterface);
            PerInterface<M> pi = (wr == null) ? null : wr.get();
            if (pi == null) {
                try {
                    MBeanAnalyzer<M> analyzer = getAnalyzer(mbeanInterface);
                    MBeanInfo mbeanInfo =
                            makeInterfaceMBeanInfo(mbeanInterface, analyzer);
                    pi = new PerInterface<M>(mbeanInterface, this, analyzer,
                            mbeanInfo);
                    wr = new WeakReference<PerInterface<M>>(pi);
                    map.put(mbeanInterface, wr);
                } catch (Exception x) {
                    throw Introspector.throwException(mbeanInterface,x);
                }
            }
            return pi;
        }
    }
    
    /**
     * Make the MBeanInfo skeleton for the given MBean interface using
     * the given analyzer.  This will never be the MBeanInfo of any real
     * MBean (because the getClassName() must be a concrete class), but
     * its MBeanAttributeInfo[] and MBeanOperationInfo[] can be inserted
     * into such an MBeanInfo, and its Descriptor can be the basis for
     * the MBeanInfo's Descriptor.
     */
    private MBeanInfo makeInterfaceMBeanInfo(Class<?> mbeanInterface,
            MBeanAnalyzer<M> analyzer) {
        final MBeanInfoMaker maker = new MBeanInfoMaker();
        analyzer.visit(maker);
        final String description =
                "Information on the management interface of the MBean";
        return maker.makeMBeanInfo(mbeanInterface, description);
    }
    
    /** True if the given getter and setter are consistent. */
    final boolean consistent(M getter, M setter) {
        return (getter == null || setter == null ||
                getGenericReturnType(getter).equals(getGenericParameterTypes(setter)[0]));
    }
    
    /**
     * Invoke the given M on the given target with the given args and cookie.
     * Wrap exceptions appropriately.
     */
    final Object invokeM(M m, Object target, Object[] args, Object cookie)
    throws MBeanException, ReflectionException {
        try {
            return invokeM2(m, target, args, cookie);
        } catch (InvocationTargetException e) {
            unwrapInvocationTargetException(e);
            throw new RuntimeException(e); // not reached
        } catch (IllegalAccessException e) {
            throw new ReflectionException(e, e.toString());
        }
        /* We do not catch and wrap RuntimeException or Error,
         * because we're in a DynamicMBean, so the logic for DynamicMBeans
         * will do the wrapping.
         */
    }
    
    /**