mbeanclientinterceptor.java

来自「spring framework 2.5.4源代码」· Java 代码 · 共 514 行 · 第 1/2 页

				this.allowedOperations.put(new MethodCacheKey(opInfo.getName(), paramTypes), opInfo);
			}
		}
		catch (ClassNotFoundException ex) {
			throw new MBeanInfoRetrievalException("Unable to locate class specified in method signature", ex);
		}
		catch (IntrospectionException ex) {
			throw new MBeanInfoRetrievalException("Unable to obtain MBean info for bean [" + this.objectName + "]", ex);
		}
		catch (InstanceNotFoundException ex) {
			// if we are this far this shouldn't happen, but...
			throw new MBeanInfoRetrievalException("Unable to obtain MBean info for bean [" + this.objectName +
					"]: it is likely that this bean was unregistered during the proxy creation process",
					ex);
		}
		catch (ReflectionException ex) {
			throw new MBeanInfoRetrievalException("Unable to read MBean info for bean [ " + this.objectName + "]", ex);
		}
		catch (IOException ex) {
			throw new MBeanInfoRetrievalException(
					"An IOException occurred when communicating with the MBeanServer. " +
							"It is likely that you are communicating with a remote MBeanServer. " +
							"Check the inner exception for exact details.", ex);
		}
	}

	/**
	 * Return whether this client interceptor has already been prepared,
	 * i.e. has already looked up the server and cached all metadata.
	 */
	protected boolean isPrepared() {
		synchronized (this.preparationMonitor) {
			return (this.invocationHandler != null || this.allowedAttributes != null);
		}
	}


	/**
	 * Route the invocation to the configured managed resource. Correctly routes JavaBean property
	 * access to <code>MBeanServerConnection.get/setAttribute</code> and method invocation to
	 * <code>MBeanServerConnection.invoke</code>. Any attempt to invoke a method that does not
	 * correspond to an attribute or operation defined in the management interface of the managed
	 * resource results in an <code>InvalidInvocationException</code>.
	 * @param invocation the <code>MethodInvocation</code> to re-route.
	 * @return the value returned as a result of the re-routed invocation.
	 * @throws InvocationFailureException if the invocation does not match an attribute or
	 * operation on the management interface of the resource.
	 * @throws Throwable typically as the result of an error during invocation
	 */
	public Object invoke(MethodInvocation invocation) throws Throwable {
		// Lazily connect to MBeanServer if necessary.
		synchronized (this.preparationMonitor) {
			if (!isPrepared()) {
				prepare();
			}
		}
		Method method = invocation.getMethod();
		try {
			Object result = null;
			if (this.invocationHandler != null) {
				result = this.invocationHandler.invoke(invocation.getThis(), method, invocation.getArguments());
			}
			else {
				PropertyDescriptor pd = BeanUtils.findPropertyForMethod(method);
				if (pd != null) {
					result = invokeAttribute(pd, invocation);
				}
				else {
					result = invokeOperation(method, invocation.getArguments());
				}
			}
			return convertResultValueIfNecessary(result, method.getReturnType());
		}
		catch (MBeanException ex) {
			throw ex.getTargetException();
		}
		catch (RuntimeMBeanException ex) {
			throw ex.getTargetException();
		}
		catch (RuntimeErrorException ex) {
			throw ex.getTargetError();
		}
		catch (RuntimeOperationsException ex) {
			// This one is only thrown by the JMX 1.2 RI, not by the JDK 1.5 JMX code.
			RuntimeException rex = ex.getTargetException();
			if (rex instanceof RuntimeMBeanException) {
				throw ((RuntimeMBeanException) rex).getTargetException();
			}
			else if (rex instanceof RuntimeErrorException) {
				throw ((RuntimeErrorException) rex).getTargetError();
			}
			else {
				throw rex;
			}
		}
		catch (OperationsException ex) {
			if (ReflectionUtils.declaresException(method, ex.getClass())) {
				throw ex;
			}
			else {
				throw new InvalidInvocationException(ex.getMessage());
			}
		}
		catch (JMException ex) {
			if (ReflectionUtils.declaresException(method, ex.getClass())) {
				throw ex;
			}
			else {
				throw new InvocationFailureException("JMX access failed", ex);
			}
		}
		catch (IOException ex) {
			if (ReflectionUtils.declaresException(method, ex.getClass())) {
				throw ex;
			}
			else {
				throw new InvocationFailureException("I/O failure during JMX access", ex);
			}
		}
	}

	private Object invokeAttribute(PropertyDescriptor pd, MethodInvocation invocation)
			throws JMException, IOException {

		String attributeName = JmxUtils.getAttributeName(pd, this.useStrictCasing);
		MBeanAttributeInfo inf = (MBeanAttributeInfo) this.allowedAttributes.get(attributeName);
		// If no attribute is returned, we know that it is not defined in the
		// management interface.
		if (inf == null) {
			throw new InvalidInvocationException(
					"Attribute '" + pd.getName() + "' is not exposed on the management interface");
		}
		if (invocation.getMethod().equals(pd.getReadMethod())) {
			if (inf.isReadable()) {
				return this.server.getAttribute(this.objectName, attributeName);
			}
			else {
				throw new InvalidInvocationException("Attribute '" + attributeName + "' is not readable");
			}
		}
		else if (invocation.getMethod().equals(pd.getWriteMethod())) {
			if (inf.isWritable()) {
				this.server.setAttribute(this.objectName, new Attribute(attributeName, invocation.getArguments()[0]));
				return null;
			}
			else {
				throw new InvalidInvocationException("Attribute '" + attributeName + "' is not writable");
			}
		}
		else {
			throw new IllegalStateException(
					"Method [" + invocation.getMethod() + "] is neither a bean property getter nor a setter");
		}
	}

	/**
	 * Routes a method invocation (not a property get/set) to the corresponding
	 * operation on the managed resource.
	 * @param method the method corresponding to operation on the managed resource.
	 * @param args the invocation arguments
	 * @return the value returned by the method invocation.
	 */
	private Object invokeOperation(Method method, Object[] args) throws JMException, IOException {
		MethodCacheKey key = new MethodCacheKey(method.getName(), method.getParameterTypes());
		MBeanOperationInfo info = (MBeanOperationInfo) this.allowedOperations.get(key);
		if (info == null) {
			throw new InvalidInvocationException("Operation '" + method.getName() +
					"' is not exposed on the management interface");
		}
		String[] signature = null;
		synchronized (this.signatureCache) {
			signature = (String[]) this.signatureCache.get(method);
			if (signature == null) {
				signature = JmxUtils.getMethodSignature(method);
				this.signatureCache.put(method, signature);
			}
		}
		return this.server.invoke(this.objectName, method.getName(), args, signature);
	}

	/**
	 * Convert the given result object (from attribute access or operation invocation)
	 * to the specified target class for returning from the proxy method.
	 * @param result the result object as returned by the <code>MBeanServer</code>
	 * @param targetClass the result type of the proxy method that's been invoked
	 * @return the converted result object, or the passed-in object if no conversion
	 * is necessary
	 */
	protected Object convertResultValueIfNecessary(Object result, Class targetClass) {
		try {
			if (result == null) {
				return null;
			}
			if (ClassUtils.isAssignableValue(targetClass, result)) {
				return result;
			}
			if (result instanceof CompositeData) {
				Method fromMethod = targetClass.getMethod("from", new Class[] {CompositeData.class});
				return ReflectionUtils.invokeMethod(fromMethod, null, new Object[] {result});
			}
			else if (result instanceof TabularData) {
				Method fromMethod = targetClass.getMethod("from", new Class[] {TabularData.class});
				return ReflectionUtils.invokeMethod(fromMethod, null, new Object[] {result});
			}
			else {
				throw new InvocationFailureException(
						"Incompatible result value [" + result + "] for target type [" + targetClass.getName() + "]");
			}
		}
		catch (NoSuchMethodException ex) {
			throw new InvocationFailureException(
					"Could not obtain 'find(CompositeData)' / 'find(TabularData)' method on target type [" +
							targetClass.getName() + "] for conversion of MXBean data structure [" + result + "]");
		}
	}

	public void destroy() {
		this.connector.close();
	}


	/**
	 * Simple wrapper class around a method name and its signature.
	 * Used as the key when caching methods.
	 */
	private static class MethodCacheKey {

		private final String name;

		private final Class[] parameterTypes;

		/**
		 * Create a new instance of <code>MethodCacheKey</code> with the supplied
		 * method name and parameter list.
		 * @param name the name of the method
		 * @param parameterTypes the arguments in the method signature
		 */
		public MethodCacheKey(String name, Class[] parameterTypes) {
			this.name = name;
			this.parameterTypes = (parameterTypes != null ? parameterTypes : new Class[0]);
		}

		public boolean equals(Object other) {
			if (other == this) {
				return true;
			}
			MethodCacheKey otherKey = (MethodCacheKey) other;
			return (this.name.equals(otherKey.name) && Arrays.equals(this.parameterTypes, otherKey.parameterTypes));
		}

		public int hashCode() {
			return this.name.hashCode();
		}
	}

}