registry.java

业界著名的tomcat服务器的最新6.0的源代码。

     */
    public synchronized int getId( String domain, String name) {
        if( domain==null) {
            domain="";
        }
        Hashtable domainTable=(Hashtable)idDomains.get( domain );
        if( domainTable == null ) {
            domainTable=new Hashtable();
            idDomains.put( domain, domainTable); 
        }
        if( name==null ) {
            name="";
        }
        Integer i=(Integer)domainTable.get(name);
        
        if( i!= null ) {
            return i.intValue();
        }

        int id[]=(int [])ids.get( domain );
        if( id == null ) {
            id=new int[1];
            ids.put( domain, id); 
        }
        int code=id[0]++;
        domainTable.put( name, new Integer( code ));
        return code;
    }
    
    // -------------------- Metadata   --------------------
    // methods from 1.0

    /**
     * Add a new bean metadata to the set of beans known to this registry.
     * This is used by internal components.
     *
     * @param bean The managed bean to be added
     * @since 1.0
     */
    public void addManagedBean(ManagedBean bean) {
        // XXX Use group + name
        descriptors.put(bean.getName(), bean);
        if( bean.getType() != null ) {
            descriptorsByClass.put( bean.getType(), bean );
        }
    }


    /**
     * Find and return the managed bean definition for the specified
     * bean name, if any; otherwise return <code>null</code>.
     *
     * @param name Name of the managed bean to be returned. Since 1.1, both
     *   short names or the full name of the class can be used.
     * @since 1.0
     */
    public ManagedBean findManagedBean(String name) {
        // XXX Group ?? Use Group + Type
        ManagedBean mb=((ManagedBean) descriptors.get(name));
        if( mb==null )
            mb=(ManagedBean)descriptorsByClass.get(name);
        return mb;
    }
    
    /**
     * Return the set of bean names for all managed beans known to
     * this registry.
     *
     * @since 1.0
     */
    public String[] findManagedBeans() {
        return ((String[]) descriptors.keySet().toArray(new String[0]));
    }


    /**
     * Return the set of bean names for all managed beans known to
     * this registry that belong to the specified group.
     *
     * @param group Name of the group of interest, or <code>null</code>
     *  to select beans that do <em>not</em> belong to a group
     * @since 1.0
     */
    public String[] findManagedBeans(String group) {

        ArrayList results = new ArrayList();
        Iterator items = descriptors.values().iterator();
        while (items.hasNext()) {
            ManagedBean item = (ManagedBean) items.next();
            if ((group == null) && (item.getGroup() == null)) {
                results.add(item.getName());
            } else if (group.equals(item.getGroup())) {
                results.add(item.getName());
            }
        }
        String values[] = new String[results.size()];
        return ((String[]) results.toArray(values));

    }


    /**
     * Remove an existing bean from the set of beans known to this registry.
     *
     * @param bean The managed bean to be removed
     * @since 1.0
     */
    public void removeManagedBean(ManagedBean bean) {
       // TODO: change this to use group/name
        descriptors.remove(bean.getName());
        descriptorsByClass.remove( bean.getType());
    }

    // -------------------- Deprecated 1.0 methods  --------------------
    
    /**
     * Factory method to create (if necessary) and return our
     * <code>MBeanServer</code> instance.
     *
     * @since 1.0
     * @deprecated Use the instance method
     */
    public static MBeanServer getServer() {
        return Registry.getRegistry().getMBeanServer();
    }

    /**
     * Set the <code>MBeanServer</code> to be utilized for our
     * registered management beans.
     *
     * @param mbeanServer The new <code>MBeanServer</code> instance
     * @since 1.0
     * @deprecated Use the instance method
     */
    public static void setServer(MBeanServer mbeanServer) {
        Registry.getRegistry().setMBeanServer(mbeanServer);
    }

    /**
     * Load the registry from the XML input found in the specified input
     * stream.
     *
     * @param stream InputStream containing the registry configuration
     *  information
     *
     * @exception Exception if any parsing or processing error occurs
     * @deprecated use normal class method instead
     * @since 1.0
     */
    public static void loadRegistry(InputStream stream) throws Exception {
        Registry registry = getRegistry();
        registry.loadMetadata(stream);
    }

    /** Get a "singelton" registry, or one per thread if setUseContextLoader 
     * was called 
     * 
     * @deprecated Not enough info - use the method that takes CL and domain
     * @since 1.0 
     */ 
    public synchronized static Registry getRegistry() {
        return getRegistry(null, null);
    }    

    // -------------------- Helpers  --------------------

    /** Get the type of an attribute of the object, from the metadata.
     *
     * @param oname
     * @param attName
     * @return null if metadata about the attribute is not found
     * @since 1.1
     */
    public String getType( ObjectName oname, String attName )
    {
        String type=null;
        MBeanInfo info=null;
        try {
            info=server.getMBeanInfo(oname);
        } catch (Exception e) {
            log.info( "Can't find metadata for object" + oname );
            return null;
        }

        MBeanAttributeInfo attInfo[]=info.getAttributes();
        for( int i=0; i<attInfo.length; i++ ) {
            if( attName.equals(attInfo[i].getName())) {
                type=attInfo[i].getType();
                return type;
            }
        }
        return null;
    }

    /** Find the operation info for a method
     * 
     * @param oname
     * @param opName
     * @return the operation info for the specified operation
     */ 
    public MBeanOperationInfo getMethodInfo( ObjectName oname, String opName )
    {
        String type=null;
        MBeanInfo info=null;
        try {
            info=server.getMBeanInfo(oname);
        } catch (Exception e) {
            log.info( "Can't find metadata " + oname );
            return null;
        }
        MBeanOperationInfo attInfo[]=info.getOperations();
        for( int i=0; i<attInfo.length; i++ ) {
            if( opName.equals(attInfo[i].getName())) {
                return attInfo[i];
            }
        }
        return null;
    }

    /** Unregister a component. This is just a helper that
     * avoids exceptions by checking if the mbean is already registered
     *
     * @param oname
     */
    public void unregisterComponent( ObjectName oname ) {
        try {
            if( getMBeanServer().isRegistered(oname)) {
                getMBeanServer().unregisterMBean(oname);
            }
        } catch( Throwable t ) {
            log.error( "Error unregistering mbean ", t);
        }
    }

    /**
     * Factory method to create (if necessary) and return our
     * <code>MBeanServer</code> instance.
     *
     */
    public synchronized MBeanServer getMBeanServer() {
        long t1=System.currentTimeMillis();

        if (server == null) {
            if( MBeanServerFactory.findMBeanServer(null).size() > 0 ) {
                server=(MBeanServer)MBeanServerFactory.findMBeanServer(null).get(0);
                if( log.isDebugEnabled() ) {
                    log.debug("Using existing MBeanServer " + (System.currentTimeMillis() - t1 ));
                }
            } else {
                server=MBeanServerFactory.createMBeanServer();
                if( log.isDebugEnabled() ) {
                    log.debug("Creating MBeanServer"+ (System.currentTimeMillis() - t1 ));
                }
            }
        }
        return (server);
    }

    /** Find or load metadata. 
     */ 
    public ManagedBean findManagedBean(Object bean, Class beanClass, String type)
        throws Exception
    {
        if( bean!=null && beanClass==null ) {
            beanClass=bean.getClass();
        }
        
        if( type==null ) {
            type=beanClass.getName();
        }
        
        // first look for existing descriptor
        ManagedBean managed = findManagedBean(type);

        // Search for a descriptor in the same package
        if( managed==null ) {
            // check package and parent packages
            if( log.isDebugEnabled() ) {
                log.debug( "Looking for descriptor ");
            }
            findDescriptor( beanClass, type );

            managed=findManagedBean(type);
        }
        
        if( bean instanceof DynamicMBean ) {
            if( log.isDebugEnabled() ) {
                log.debug( "Dynamic mbean support ");
            }
            // Dynamic mbean
            loadDescriptors("MbeansDescriptorsDynamicMBeanSource",
                    bean, type);

            managed=findManagedBean(type);
        }

        // Still not found - use introspection
        if( managed==null ) {
            if( log.isDebugEnabled() ) {
                log.debug( "Introspecting ");
            }

            // introspection
            loadDescriptors("MbeansDescriptorsIntrospectionSource",
                    beanClass, type);

            managed=findManagedBean(type);
            if( managed==null ) {
                log.warn( "No metadata found for " + type );
                return null;
            }
            managed.setName( type );
            addManagedBean(managed);
        }
        return managed;
    }
    

    /** EXPERIMENTAL Convert a string to object, based on type. Used by several
     * components. We could provide some pluggability. It is here to keep
     * things consistent and avoid duplication in other tasks 
     * 
     * @param type Fully qualified class name of the resulting value
     * @param value String value to be converted
     * @return Converted value
     */ 
    public Object convertValue(String type, String value)
    {
        Object objValue=value;
        
        if( type==null || "java.lang.String".equals( type )) {
            // string is default
            objValue=value;
        } else if( "javax.management.ObjectName".equals( type ) ||
                "ObjectName".equals( type )) {
            try {
                objValue=new ObjectName( value );
            } catch (MalformedObjectNameException e) {
                return null;
            }
        } else if( "java.lang.Integer".equals( type ) ||
                "int".equals( type )) {
            objValue=new Integer( value );
        } else if( "java.lang.Long".equals( type ) ||
                "long".equals( type )) {
            objValue=new Long( value );