src/main/java/org/apache/sling/jmx/provider/impl/AttributeResource.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.sling.jmx.provider.impl;

import java.lang.reflect.Array;
import java.util.HashMap;
import java.util.Map;

import javax.management.MBeanAttributeInfo;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.TabularData;

import org.apache.sling.api.resource.AbstractResource;
import org.apache.sling.api.resource.ResourceMetadata;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.resource.ValueMap;
import org.apache.sling.api.wrappers.ValueMapDecorator;

public class AttributeResource extends AbstractResource {

    private final String path;

    private final ResourceResolver resourceResolver;

    private final ResourceMetadata metadata = new ResourceMetadata();

    private final MBeanAttributeInfo info;

    private final MBeanServer server;

    private final ObjectName on;

    public AttributeResource(final MBeanServer server,
                             final ObjectName on,
                             final ResourceResolver resolver, final String p, final MBeanAttributeInfo mai) {
        this.resourceResolver = resolver;
        this.path = p;
        this.info = mai;
        this.on = on;
        this.server = server;
    }

    /**
     * @see org.apache.sling.api.resource.Resource#getPath()
     */
    public String getPath() {
        return this.path;
    }

    /**
     * @see org.apache.sling.api.resource.Resource#getResourceType()
     */
    public String getResourceType() {
        return "sling:mbeanattribute";
    }

    /**
     * @see org.apache.sling.api.resource.Resource#getResourceSuperType()
     */
    public String getResourceSuperType() {
        return null;
    }

    /**
     * @see org.apache.sling.api.resource.Resource#getResourceMetadata()
     */
    public ResourceMetadata getResourceMetadata() {
        return metadata;
    }

    /**
     * @see org.apache.sling.api.resource.Resource#getResourceResolver()
     */
    public ResourceResolver getResourceResolver() {
        return this.resourceResolver;
    }

    @Override
    public <AdapterType> AdapterType adaptTo(final Class<AdapterType> type) {
        if ( type == ValueMap.class || type == Map.class ) {
            final Map<String, Object> propMap = this.getPropertiesMap();
            return (AdapterType) new ValueMapDecorator(propMap);
        }
        return super.adaptTo(type);
    }

    private Map<String, Object> getPropertiesMap() {
        final Map<String, Object> result = new HashMap<String, Object>();
        result.put(ResourceResolver.PROPERTY_RESOURCE_TYPE, this.getResourceType());
        if ( this.getResourceSuperType() != null ) {
            result.put("sling:resourceSuperType", this.getResourceSuperType());
        }

        if ( info.getDescription() != null ) {
            result.put("mbean:description", info.getDescription());
        }
        result.put("mbean:type", info.getType());

        try {
            final Object value = server.getAttribute(this.on, info.getName());
            if ( value != null ) {
                if ( value.getClass().isArray() ) {
                    final int length = Array.getLength(value);
                    final Object[] values = new Object[length];
                    for (int i = 0; i < length; i ++) {
                        final Object o = Array.get(value, i);
                        values[i] = convert(o);
                    }
                    result.put("mbean:value", values);
                } else if (value instanceof TabularData) {
                    // TODO
                } else if (value instanceof CompositeData) {
                    // TODO
                } else {
                    result.put("mbean:value", convert(value));
                }
            }
        } catch (final Exception ignore) {
            // ignore, but put this as info
            result.put("mbean:exception", ignore.getMessage());
        }
        return result;
    }

    private Object convert(final Object value) {
        if ( value == null ) {
            return "";
        } else if ( value instanceof String ) {
            return value;
        } else if ( value instanceof Number ) {
            return value;
        } else if ( value instanceof Boolean ) {
            return value;
        } else if ( value instanceof Character ) {
            return value;
        }
        return value.toString();
    }
}