# ModelMBeanBuilder.java

    /*
     * Copyright (c) 2010, Rickard Öberg. All Rights Reserved.
     *
     * Licensed 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.qi4j.library.jmx;

    import java.util.ArrayList;
    import java.util.List;
    import javax.management.Descriptor;
    import javax.management.MBeanException;
    import javax.management.MBeanParameterInfo;
    import javax.management.ObjectName;
    import javax.management.modelmbean.*;

    /**
     * Helper builder for ModelMBeans
     */
    public class ModelMBeanBuilder
    {
        List<ModelMBeanAttributeInfo> attributes = new ArrayList<ModelMBeanAttributeInfo>();
        List<ModelMBeanConstructorInfo> constructors = new ArrayList<ModelMBeanConstructorInfo>();
        List<ModelMBeanOperationInfo> operations = new ArrayList<ModelMBeanOperationInfo>();
        List<ModelMBeanNotificationInfo> notifications = new ArrayList<ModelMBeanNotificationInfo>();

        ObjectName objectName;
        String displayName;
        private final String className;

        public ModelMBeanBuilder( ObjectName objectName, String displayName, String className )
        {
            this.objectName = objectName;
            this.displayName = displayName;
            this.className = className;
        }

        public ModelMBeanBuilder attribute( String name, String displayName, String type, String description, String getMethod, String setMethod )
        {
            Descriptor stateDesc = new DescriptorSupport();
            stateDesc.setField( "name", name );
            stateDesc.setField( "descriptorType", "attribute" );
            stateDesc.setField( "displayName", displayName );
            if (getMethod != null)
            {
                stateDesc.setField( "getMethod", getMethod );

                operation( getMethod, description, type, ModelMBeanOperationInfo.INFO );
            }

            if (setMethod != null)
            {
                stateDesc.setField( "setMethod", setMethod );
                operation( setMethod, description, type, ModelMBeanOperationInfo.INFO, new MBeanParameterInfo("Value", type, description) );
            }

            ModelMBeanAttributeInfo attributeInfo = new ModelMBeanAttributeInfo(
                    name,
                    type,
                    description,
                    getMethod != null,
                    setMethod != null,
                    getMethod != null && getMethod.startsWith( "is" ),
                    stateDesc );
            attributes.add( attributeInfo );

            return this;
        }

        public ModelMBeanAttributeInfo getAttribute(String name)
        {
            for (ModelMBeanAttributeInfo attribute : attributes)
            {
                if (attribute.getName().equals(name))
                    return attribute;
            }

            return null;
        }

        public ModelMBeanBuilder operation( String name, String description, String returnType, int impact, MBeanParameterInfo... parameters)
        {
            Descriptor stateDesc = new DescriptorSupport();
            stateDesc.setField( "name", name );
            stateDesc.setField( "descriptorType", "operation" );
            stateDesc.setField( "class", className );
            stateDesc.setField( "role", "operation" );
            stateDesc.setField( "targetType", "objectReference" );

            ModelMBeanOperationInfo operationInfo = new ModelMBeanOperationInfo(
                    name,
                    description,
                    parameters,
                    returnType,
                    impact,
                    stateDesc);
            operations.add( operationInfo );

            return this;
        }

        public RequiredModelMBean newModelMBean() throws MBeanException
        {
            Descriptor mmbDesc = new DescriptorSupport();
            mmbDesc.setField( "name", objectName.toString() );
            mmbDesc.setField( "descriptorType", "mbean" );
            mmbDesc.setField( "displayName", displayName );

            ModelMBeanInfo modelMBeanInfo = new ModelMBeanInfoSupport(
                    className,
                    displayName,
                    attributes.toArray( new ModelMBeanAttributeInfo[attributes.size()]),
                    constructors.toArray( new ModelMBeanConstructorInfo[constructors.size()]),
                    operations.toArray( new ModelMBeanOperationInfo[operations.size()]),
                    notifications.toArray( new ModelMBeanNotificationInfo[notifications.size()]) );

            modelMBeanInfo.setMBeanDescriptor( mmbDesc );

            return new RequiredModelMBean(modelMBeanInfo);
        }
    }