managedbean.java

业界著名的tomcat服务器的最新6.0的源代码。

    }


    /**
     * Create and return a <code>ModelMBean</code> that has been
     * preconfigured with the <code>ModelMBeanInfo</code> information
     * for this managed bean, and is associated with the specified
     * managed object instance.  The returned <code>ModelMBean</code>
     * will <strong>NOT</strong> have been registered with our
     * <code>MBeanServer</code>.
     *
     * @param instance Instanced of the managed object, or <code>null</code>
     *  for no associated instance
     *
     * @exception InstanceNotFoundException if the managed resource
     *  object cannot be found
     * @exception InvalidTargetObjectTypeException if our MBean cannot
     *  handle object references (should never happen)
     * @exception MBeanException if a problem occurs instantiating the
     *  <code>ModelMBean</code> instance
     * @exception RuntimeOperationsException if a JMX runtime error occurs
     */
    public DynamicMBean createMBean(Object instance)
        throws InstanceNotFoundException,
        MBeanException, RuntimeOperationsException {

        BaseModelMBean mbean = null;

        // Load the ModelMBean implementation class
        if(getClassName().equals(BASE_MBEAN)) {
            // Skip introspection
            mbean = new BaseModelMBean();
        } else {
            Class clazz = null;
            Exception ex = null;
            try {
                clazz = Class.forName(getClassName());
            } catch (Exception e) {
            }
          
            if( clazz==null ) {  
                try {
                    ClassLoader cl= Thread.currentThread().getContextClassLoader();
                    if ( cl != null)
                        clazz= cl.loadClass(getClassName());
                } catch (Exception e) {
                    ex=e;
                }
            }
    
            if( clazz==null) { 
                throw new MBeanException
                    (ex, "Cannot load ModelMBean class " + getClassName());
            }
            try {
                // Stupid - this will set the default minfo first....
                mbean = (BaseModelMBean) clazz.newInstance();
            } catch (RuntimeOperationsException e) {
                throw e;
            } catch (Exception e) {
                throw new MBeanException
                    (e, "Cannot instantiate ModelMBean of class " +
                     getClassName());
            }
        }
        
        mbean.setManagedBean(this);
        
        // Set the managed resource (if any)
        try {
            if (instance != null)
                mbean.setManagedResource(instance, "ObjectReference");
        } catch (InstanceNotFoundException e) {
            throw e;
        }
        return (mbean);

    }


    /**
     * Create and return a <code>ModelMBeanInfo</code> object that
     * describes this entire managed bean.
     */
    MBeanInfo getMBeanInfo() {

        // Return our cached information (if any)
        if (info != null)
            return (info);

        // Create subordinate information descriptors as required
        AttributeInfo attrs[] = getAttributes();
        MBeanAttributeInfo attributes[] =
            new MBeanAttributeInfo[attrs.length];
        for (int i = 0; i < attrs.length; i++)
            attributes[i] = attrs[i].createAttributeInfo();

        OperationInfo opers[] = getOperations();
        MBeanOperationInfo operations[] =
            new MBeanOperationInfo[opers.length];
        for (int i = 0; i < opers.length; i++)
            operations[i] = opers[i].createOperationInfo();


//        ConstructorInfo consts[] = getConstructors();
//        ModelMBeanConstructorInfo constructors[] =
//            new ModelMBeanConstructorInfo[consts.length];
//        for (int i = 0; i < consts.length; i++)
//            constructors[i] = consts[i].createConstructorInfo();
        
        NotificationInfo notifs[] = getNotifications();
        MBeanNotificationInfo notifications[] =
            new MBeanNotificationInfo[notifs.length];
        for (int i = 0; i < notifs.length; i++)
            notifications[i] = notifs[i].createNotificationInfo();

        
        // Construct and return a new ModelMBeanInfo object
        info = new MBeanInfo(getClassName(), 
                             getDescription(),
                             attributes, 
                             new MBeanConstructorInfo[] {}, 
                             operations, 
                             notifications);
//        try {
//            Descriptor descriptor = info.getMBeanDescriptor();
//            Iterator fields = getFields().iterator();
//            while (fields.hasNext()) {
//                FieldInfo field = (FieldInfo) fields.next();
//                descriptor.setField(field.getName(), field.getValue());
//            }
//            info.setMBeanDescriptor(descriptor);
//        } catch (MBeanException e) {
//            ;
//        }

        return (info);

    }


    /**
     * Return a string representation of this managed bean.
     */
    public String toString() {

        StringBuffer sb = new StringBuffer("ManagedBean[");
        sb.append("name=");
        sb.append(name);
        sb.append(", className=");
        sb.append(className);
        sb.append(", description=");
        sb.append(description);
        if (group != null) {
            sb.append(", group=");
            sb.append(group);
        }
        sb.append(", type=");
        sb.append(type);
        sb.append("]");
        return (sb.toString());

    }

    Method getGetter(String aname, BaseModelMBean mbean, Object resource) 
            throws AttributeNotFoundException, MBeanException, ReflectionException {
        // TODO: do we need caching ? JMX is for management, it's not supposed to require lots of performance.
        Method m=null; // (Method)getAttMap.get( name );

        if( m==null ) {
            AttributeInfo attrInfo = (AttributeInfo)attributes.get(aname);
            // Look up the actual operation to be used
            if (attrInfo == null)
                throw new AttributeNotFoundException(" Cannot find attribute " + aname + " for " + resource);
            
            String getMethod = attrInfo.getGetMethod();
            if (getMethod == null)
                throw new AttributeNotFoundException("Cannot find attribute " + aname + " get method name");

            Object object = null;
            NoSuchMethodException exception = null;
            try {
                object = mbean;
                m = object.getClass().getMethod(getMethod, NO_ARGS_PARAM_SIG);
            } catch (NoSuchMethodException e) {
                exception = e;;
            }
            if( m== null && resource != null ) {
                try {
                    object = resource;
                    m = object.getClass().getMethod(getMethod, NO_ARGS_PARAM_SIG);
                    exception=null;
                } catch (NoSuchMethodException e) {
                    exception = e;
                }
            }
            if( exception != null )
                throw new ReflectionException(exception,
                                              "Cannot find getter method " + getMethod);
            //getAttMap.put( name, m );
        }

        return m;
    }

    public Method getSetter(String aname, BaseModelMBean bean, Object resource) 
            throws AttributeNotFoundException, MBeanException, ReflectionException {
        // Cache may be needed for getters, but it is a really bad idea for setters, this is far 
        // less frequent.
        Method m=null;//(Method)setAttMap.get( name );

        if( m==null ) {
            AttributeInfo attrInfo = (AttributeInfo)attributes.get(aname);
            if (attrInfo == null)
                throw new AttributeNotFoundException(" Cannot find attribute " + aname);

            // Look up the actual operation to be used
            String setMethod = attrInfo.getSetMethod();
            if (setMethod == null)
                throw new AttributeNotFoundException("Cannot find attribute " + aname + " set method name");

            String argType=attrInfo.getType();

            Class signature[] = new Class[] { BaseModelMBean.getAttributeClass( argType ) };

            Object object = null;
            NoSuchMethodException exception = null;
            try {
                object = this;
                m = object.getClass().getMethod(setMethod, signature);
            } catch (NoSuchMethodException e) {
                exception = e;;
            }
            if( m== null && resource != null ) {
                try {
                    object = resource;
                    m = object.getClass().getMethod(setMethod, signature);
                    exception=null;
                } catch (NoSuchMethodException e) {
                    exception = e;
                }
            }
            if( exception != null )
                throw new ReflectionException(exception,
                                              "Cannot find setter method " + setMethod +
                        " " + resource);
            //setAttMap.put( name, m );
        }

        return m;
    }

    public Method getInvoke(String aname, Object[] params, String[] signature, BaseModelMBean bean, Object resource) 
            throws MBeanException, ReflectionException {
        Method method = null;
        if (method == null) {
            if (params == null)
                params = new Object[0];
            if (signature == null)
                signature = new String[0];
            if (params.length != signature.length)
                throw new RuntimeOperationsException(
                        new IllegalArgumentException(
                                "Inconsistent arguments and signature"),
                        "Inconsistent arguments and signature");

            // Acquire the ModelMBeanOperationInfo information for
            // the requested operation
            OperationInfo opInfo = (OperationInfo)operations.get(aname);
            if (opInfo == null)
                throw new MBeanException(new ServiceNotFoundException(
                        "Cannot find operation " + aname),
                        "Cannot find operation " + aname);

            // Prepare the signature required by Java reflection APIs
            // FIXME - should we use the signature from opInfo?
            Class types[] = new Class[signature.length];
            for (int i = 0; i < signature.length; i++) {
                types[i] = BaseModelMBean.getAttributeClass(signature[i]);
            }

            // Locate the method to be invoked, either in this MBean itself
            // or in the corresponding managed resource
            // FIXME - Accessible methods in superinterfaces?
            Object object = null;
            Exception exception = null;
            try {
                object = this;
                method = object.getClass().getMethod(aname, types);
            } catch (NoSuchMethodException e) {
                exception = e;
                ;
            }
            try {
                if ((method == null) && (resource != null)) {
                    object = resource;
                    method = object.getClass().getMethod(aname, types);
                }
            } catch (NoSuchMethodException e) {
                exception = e;
            }
            if (method == null) {
                throw new ReflectionException(exception, "Cannot find method "
                        + aname + " with this signature");
            }
            // invokeAttMap.put(mkey, method);
        }
        return method;
    }


}