dynamicmbeanproxy.java

Tomcat 4.1与WebServer集成组件的源代码包.

            String name=methods[j].getName();
            
            if( name.startsWith( "get" ) ) {
                if( methods[j].getParameterTypes().length != 0 ) {
                    continue;
                }
                if( ! Modifier.isPublic( methods[j].getModifiers() ) ) {
                    //log.debug("not public " + methods[j] );
                    continue;
                }
                Class ret=methods[j].getReturnType();
                if( ! supportedType( ret ) ) {
                    if( log.isDebugEnabled() )
                        log.debug("Unsupported " + ret );
                    continue;
                }
                name=unCapitalize( name.substring(3));

                getAttMap.put( name, methods[j] );
                // just a marker, we don't use the value 
                attMap.put( name, methods[j] );
            } else if( name.startsWith( "is" ) ) {
                // not used in our code. Add later

            } else if( name.startsWith( "set" ) ) {
                Class params[]=methods[j].getParameterTypes();
                if( params.length != 1 ) {
                    continue;
                }
                if( ! Modifier.isPublic( methods[j].getModifiers() ) )
                    continue;
                Class ret=params[0];
                if( ! supportedType( ret ) ) {
                    continue;
                }
                name=unCapitalize( name.substring(3));
                setAttMap.put( name, methods[j] );
                attMap.put( name, methods[j] );
            } else {
                if( methods[j].getParameterTypes().length != 0 ) {
                    continue;
                }
                if( methods[j].getDeclaringClass() == Object.class )
                    continue;
                if( ! Modifier.isPublic( methods[j].getModifiers() ) )
                    continue;
                invokeAttMap.put( name, methods[j]);
            }
        }
    }

    /**
     * @todo Find if the 'className' is the name of the MBean or
     *       the real class ( I suppose first )
     * @todo Read (optional) descriptions from a .properties, generated
     *       from source
     * @todo Deal with constructors
     *       
     */
    public MBeanInfo getMBeanInfo() {
        if( methods==null ) {
            init();
        }
        try {
            MBeanAttributeInfo attributes[]=new MBeanAttributeInfo[attMap.size()];

            Enumeration en=attMap.keys();
            int i=0;
            while( en.hasMoreElements() ) {
                String name=(String)en.nextElement();
                attributes[i++]=new MBeanAttributeInfo(name, "Attribute " + name ,
                                                       (Method)getAttMap.get(name),
                                                       (Method)setAttMap.get(name));
            }
            
            MBeanOperationInfo operations[]=new MBeanOperationInfo[invokeAttMap.size()];
            
            en=invokeAttMap.keys();
            i=0;
            while( en.hasMoreElements() ) {
                String name=(String)en.nextElement();
                Method m=(Method)invokeAttMap.get(name);
                if( m!=null && name != null ) {
                    operations[i++]=new MBeanOperationInfo(name, m);
                } else {
                    System.out.println("Null arg " + name + " " + m );
                }
            }
            
            if( log.isDebugEnabled() )
                log.debug(real.getClass().getName() +  " getMBeanInfo()");
            
            return new MBeanInfo( real.getClass().getName(), /* ??? */
                                  "MBean for " + getName(),
                                  attributes,
                                  new MBeanConstructorInfo[0],
                                  operations,
                                  new MBeanNotificationInfo[0]);
        } catch( Exception ex ) {
            ex.printStackTrace();
            return null;
        }
    }

    static final Object[] NO_ARGS_PARAM=new Object[0];
    
    public Object getAttribute(String attribute)
        throws AttributeNotFoundException, MBeanException, ReflectionException
    {
        if( methods==null ) init();
        Method m=(Method)getAttMap.get( attribute );
        if( m==null ) throw new AttributeNotFoundException(attribute);

        try {
            if( log.isDebugEnabled() )
                log.debug(real.getClass().getName() +  " getAttribute " + attribute);
            return m.invoke(real, NO_ARGS_PARAM );
        } catch( IllegalAccessException ex ) {
            ex.printStackTrace();
            throw new MBeanException( ex );
        } catch( InvocationTargetException ex1 ) {
            ex1.printStackTrace();
            throw new MBeanException( ex1 );
        }
    }
    
    public void setAttribute(Attribute attribute)
        throws AttributeNotFoundException, InvalidAttributeValueException, MBeanException, ReflectionException
    {
        if( methods==null ) init();
        // XXX Send notification !!!
        Method m=(Method)setAttMap.get( attribute.getName() );
        if( m==null ) throw new AttributeNotFoundException(attribute.getName());

        try {
            log.info(real.getClass().getName() +  "setAttribute " + attribute.getName());
            m.invoke(real, new Object[] { attribute.getValue() } );
        } catch( IllegalAccessException ex ) {
            ex.printStackTrace();
            throw new MBeanException( ex );
        } catch( InvocationTargetException ex1 ) {
            ex1.printStackTrace();
            throw new MBeanException( ex1 );
        }
    }
    
    /**
     * Invoke a method. Only no param methods are supported at the moment
     * ( init, start, execute, etc ) ( that's the most common pattern we have
     *  in tomcat/ant/etc )
     *
     * @todo Implement invoke for methods with more arguments.
     */
    public Object invoke(String method, Object[] arguments, String[] params)
        throws MBeanException, ReflectionException
    {
        if( methods==null ) init();
        Method m=(Method)invokeAttMap.get( method );
        if( m==null ) return null;

        try {
            log.info(real.getClass().getName() +  "invoke " + m.getName());
            return m.invoke(real, NO_ARGS_PARAM );
        } catch( IllegalAccessException ex ) {
            throw new MBeanException( ex );
        } catch( InvocationTargetException ex1 ) {
            throw new MBeanException( ex1 );
        }
    }


    // -------------------- Auxiliary methods --------------------
    
    public AttributeList setAttributes(AttributeList attributes) {
        Iterator attE=attributes.iterator();
        while( attE.hasNext() ) {
            Attribute att=(Attribute)attE.next();

            try {
                setAttribute( att );
            } catch( Exception ex ) {
                ex.printStackTrace();
            }
        }
        return attributes;
    }

    public AttributeList getAttributes(String[] attributes) {
        AttributeList al=new AttributeList();
        if( attributes==null ) return null;
        
        for( int i=0; i<attributes.length; i++ ) {
            try {
                Attribute att=new Attribute( attributes[i], getAttribute( attributes[i] ));
                al.add( att );
            } catch( Exception ex ) {
                ex.printStackTrace();
            }
        }
        return al;
    }
    

    // -------------------- Utils --------------------

    public static String unCapitalize(String name) {
	if (name == null || name.length() == 0) {
	    return name;
	}
	char chars[] = name.toCharArray();
	chars[0] = Character.toLowerCase(chars[0]);
	return new String(chars);
    }

    private static org.apache.commons.logging.Log log=
        org.apache.commons.logging.LogFactory.getLog( DynamicMBeanProxy.class );

}