objectmbean.java

jetty SERVER連接資料庫用的軟體

//========================================================================
//Copyright 2004 Mort Bay Consulting Pty. Ltd.
//------------------------------------------------------------------------
//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.mortbay.management;

import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.Set;

import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.DynamicMBean;
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.MBeanParameterInfo;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.modelmbean.ModelMBean;

import org.mortbay.log.Log;
import org.mortbay.util.LazyList;
import org.mortbay.util.Loader;
import org.mortbay.util.TypeUtil;

/* ------------------------------------------------------------ */
/** ObjectMBean.
 * A dynamic MBean that can wrap an arbitary Object instance.
 * the attributes and methods exposed by this bean are controlled by
 * the merge of property bundles discovered by names related to all
 * superclasses and all superinterfaces.
 *
 * Attributes and methods exported may be "Object" and must exist on the
 * wrapped object, or "MBean" and must exist on a subclass of OBjectMBean
 * or "MObject" which exists on the wrapped object, but whose values are
 * converted to MBean object names.
 *
 */
public class ObjectMBean implements DynamicMBean
{
    private static Class[] OBJ_ARG = new Class[]{Object.class};

    protected Object _managed;
    private MBeanInfo _info;
    private Map _getters=new HashMap();
    private Map _setters=new HashMap();
    private Map _methods=new HashMap();
    private Set _convert=new HashSet();
    private ClassLoader _loader;
    private MBeanContainer _mbeanContainer;

    private static String OBJECT_NAME_CLASS = ObjectName.class.getName();
    private static String OBJECT_NAME_ARRAY_CLASS = ObjectName[].class.getName();

    /* ------------------------------------------------------------ */
    /**
     * Create MBean for Object. Attempts to create an MBean for the object by searching the package
     * and class name space. For example an object of the type
     *
     * <PRE>
     * class com.acme.MyClass extends com.acme.util.BaseClass implements com.acme.Iface
     * </PRE>
     *
     * Then this method would look for the following classes:
     * <UL>
     * <LI>com.acme.management.MyClassMBean
     * <LI>com.acme.util.management.BaseClassMBean
     * <LI>org.mortbay.management.ObjectMBean
     * </UL>
     *
     * @param o The object
     * @return A new instance of an MBean for the object or null.
     */
    public static Object mbeanFor(Object o)
    {
        try
        {
            Class oClass = o.getClass();
            Object mbean = null;

            while (mbean == null && oClass != null)
            {
                String pName = oClass.getPackage().getName();
                String cName = oClass.getName().substring(pName.length() + 1);
                String mName = pName + ".management." + cName + "MBean";
                

                try
                {
                    Class mClass = (Object.class.equals(oClass))?oClass=ObjectMBean.class:Loader.loadClass(oClass,mName,true);
                    if (Log.isDebugEnabled())
                        Log.debug("mbeanFor " + o + " mClass=" + mClass);

                    try
                    {
                        Constructor constructor = mClass.getConstructor(OBJ_ARG);
                        mbean=constructor.newInstance(new Object[]{o});
                    }
                    catch(Exception e)
                    {
                        Log.ignore(e);
                        if (ModelMBean.class.isAssignableFrom(mClass))
                        {
                            mbean=mClass.newInstance();
                            ((ModelMBean)mbean).setManagedResource(o, "objectReference");
                        }
                    }

                    if (Log.isDebugEnabled())
                        Log.debug("mbeanFor " + o + " is " + mbean);
                    return mbean;
                }
                catch (ClassNotFoundException e)
                {
                    if (e.toString().endsWith("MBean"))
                        Log.ignore(e);
                    else
                        Log.warn(e);
                }
                catch (Error e)
                {
                    Log.warn(e);
                    mbean = null;
                }
                catch (Exception e)
                {
                    Log.warn(e);
                    mbean = null;
                }

                oClass = oClass.getSuperclass();
            }
        }
        catch (Exception e)
        {
            Log.ignore(e);
        }
        return null;
    }


    public ObjectMBean(Object managedObject)
    {
        _managed = managedObject;
        _loader = Thread.currentThread().getContextClassLoader();
    }
    
    public Object getManagedObject()
    {
        return _managed;
    }
    
    public ObjectName getObjectName()
    {
        return null;
    }
    
    public String getObjectNameBasis()
    {
        return null;
    }

    protected void setMBeanContainer(MBeanContainer container)
    {
       this._mbeanContainer = container;
    }

    public MBeanContainer getMBeanContainer ()
    {
        return this._mbeanContainer;
    }
    
    
    public MBeanInfo getMBeanInfo()
    {
        try
        {
            if (_info==null)
            {
                // Start with blank lazy lists attributes etc.
                String desc=null;
                Object attributes=null;
                Object constructors=null;
                Object operations=null;
                Object notifications=null;

                // Find list of classes that can influence the mbean
                Class o_class=_managed.getClass();
                Object influences = findInfluences(null, _managed.getClass());

                // Set to record defined items
                Set defined=new HashSet();

                // For each influence
                for (int i=0;i<LazyList.size(influences);i++)
                {
                    Class oClass = (Class)LazyList.get(influences, i);

                    // look for a bundle defining methods
                    if (Object.class.equals(oClass))
                        oClass=ObjectMBean.class;
                    String pName = oClass.getPackage().getName();
                    String cName = oClass.getName().substring(pName.length() + 1);
                    String rName = pName.replace('.', '/') + "/management/" + cName+"-mbean";

                    try
                    {
                        Log.debug(rName);
                        ResourceBundle bundle = Loader.getResourceBundle(o_class, rName,true,Locale.getDefault());

                        
                        // Extract meta data from bundle
                        Enumeration e = bundle.getKeys();
                        while (e.hasMoreElements())
                        {
                            String key = (String)e.nextElement();
                            String value = bundle.getString(key);

                            // Determin if key is for mbean , attribute or for operation
                            if (key.equals(cName))
                            {
                                // set the mbean description
                                if (desc==null)
                                    desc=value;
                            }
                            else if (key.indexOf('(')>0)
                            {
                                // define an operation
                                if (!defined.contains(key) && key.indexOf('[')<0)
                                {
                                    defined.add(key);
                                    operations=LazyList.add(operations,defineOperation(key, value, bundle));
                                }
                            }
                            else
                            {
                                // define an attribute
                                if (!defined.contains(key))
                                {
                                    defined.add(key);
                                    attributes=LazyList.add(attributes,defineAttribute(key, value));
                                }
                            }
                        }

                    }
                    catch(MissingResourceException e)
                    {
                        Log.ignore(e);
                    }
                }

                _info = new MBeanInfo(o_class.getName(),
                                desc,
                                (MBeanAttributeInfo[])LazyList.toArray(attributes, MBeanAttributeInfo.class),
                                (MBeanConstructorInfo[])LazyList.toArray(constructors, MBeanConstructorInfo.class),
                                (MBeanOperationInfo[])LazyList.toArray(operations, MBeanOperationInfo.class),
                                (MBeanNotificationInfo[])LazyList.toArray(notifications, MBeanNotificationInfo.class));
            }
        }
        catch(RuntimeException e)
        {
            Log.warn(e);
            throw e;
        }
        return _info;
    }


    /* ------------------------------------------------------------ */
    public Object getAttribute(String name) throws AttributeNotFoundException, MBeanException, ReflectionException
    {
        Method getter = (Method) _getters.get(name);
        if (getter == null)
            throw new AttributeNotFoundException(name);
        try
        {
            Object o = _managed;
            if (getter.getDeclaringClass().isInstance(this))
                o = this; // mbean method

            // get the attribute
            Object r=getter.invoke(o, (java.lang.Object[]) null);

            // convert to ObjectName if need be.
            if (r!=null && _convert.contains(name))
            {
                if (r.getClass().isArray())
                {
                    ObjectName[] on = new ObjectName[Array.getLength(r)];
                    for (int i=0;i<on.length;i++)
                        on[i]=_mbeanContainer.findMBean(Array.get(r, i));
                    r=on;
                }
                else
                {
                    ObjectName mbean = _mbeanContainer.findMBean(r);
                    if (mbean==null)
                        return null;
                    r=mbean;
                }
            }
            return r;
        }
        catch (IllegalAccessException e)
        {
            Log.warn(Log.EXCEPTION, e);
            throw new AttributeNotFoundException(e.toString());
        }
        catch (InvocationTargetException e)
        {
            Log.warn(Log.EXCEPTION, e);
            throw new ReflectionException((Exception) e.getTargetException());
        }
    }

    /* ------------------------------------------------------------ */
    public AttributeList getAttributes(String[] names)
    {
        AttributeList results = new AttributeList(names.length);
        for (int i = 0; i < names.length; i++)
        {
            try
            {
                results.add(new Attribute(names[i], getAttribute(names[i])));
            }
            catch (Exception e)
            {
                Log.warn(Log.EXCEPTION, e);
            }
        }
        return results;
    }