org.springframework/spring-context/5.3.3 : org/springframework/jmx/access/MBeanClientInterceptor.java

MBeanClientInterceptor
https://github.com/spring-projects/spring-framework: Spring Context (Spring IO)
Apache License, Version 2.0
Juergen Hoeller
/*
 * Copyright 2002-2020 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.jmx.access;

import java.beans.PropertyDescriptor;
import java.io.IOException;
import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.management.Attribute;
import javax.management.InstanceNotFoundException;
import javax.management.IntrospectionException;
import javax.management.JMException;
import javax.management.JMX;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanServerConnection;
import javax.management.MBeanServerInvocationHandler;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.OperationsException;
import javax.management.ReflectionException;
import javax.management.RuntimeErrorException;
import javax.management.RuntimeMBeanException;
import javax.management.RuntimeOperationsException;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.TabularData;
import javax.management.remote.JMXServiceURL;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.CollectionFactory;
import org.springframework.core.MethodParameter;
import org.springframework.core.ResolvableType;
import org.springframework.jmx.support.JmxUtils;
import org.springframework.jmx.support.ObjectNameManager;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;

MethodInterceptor that routes calls to an MBean running on the supplied MBeanServerConnection. Works for both local and remote MBeanServerConnections. By default, the MBeanClientInterceptor will connect to the MBeanServer and cache MBean metadata at startup. This can be undesirable when running against a remote MBeanServer that may not be running when the application starts. Through setting the connectOnStartup property to "false", you can defer this process until the first invocation against the proxy. 
This functionality is usually used through MBeanProxyFactoryBean. See the javadoc of that class for more information. 
Author: Rob Harrop, Juergen Hoeller
See Also: MBeanProxyFactoryBean
setConnectOnStartup
Since: 1.2/**
 * {@link org.aopalliance.intercept.MethodInterceptor} that routes calls to an
 * MBean running on the supplied {@code MBeanServerConnection}.
 * Works for both local and remote {@code MBeanServerConnection}s.
 *
 * <p>By default, the {@code MBeanClientInterceptor} will connect to the
 * {@code MBeanServer} and cache MBean metadata at startup. This can
 * be undesirable when running against a remote {@code MBeanServer}
 * that may not be running when the application starts. Through setting the
 * {@link #setConnectOnStartup(boolean) connectOnStartup} property to "false",
 * you can defer this process until the first invocation against the proxy.
 *
 * <p>This functionality is usually used through {@link MBeanProxyFactoryBean}.
 * See the javadoc of that class for more information.
 *
 * @author Rob Harrop
 * @author Juergen Hoeller
 * @since 1.2
 * @see MBeanProxyFactoryBean
 * @see #setConnectOnStartup
 */
public class MBeanClientInterceptor
		implements MethodInterceptor, BeanClassLoaderAware, InitializingBean, DisposableBean {

	Logger available to subclasses. /** Logger available to subclasses. */
	protected final Log logger = LogFactory.getLog(getClass());

	@Nullable
	private MBeanServerConnection server;

	@Nullable
	private JMXServiceURL serviceUrl;

	@Nullable
	private Map<String, ?> environment;

	@Nullable
	private String agentId;

	private boolean connectOnStartup = true;

	private boolean refreshOnConnectFailure = false;

	@Nullable
	private ObjectName objectName;

	private boolean useStrictCasing = true;

	@Nullable
	private Class<?> managementInterface;

	@Nullable
	private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();

	private final ConnectorDelegate connector = new ConnectorDelegate();

	@Nullable
	private MBeanServerConnection serverToUse;

	@Nullable
	private MBeanServerInvocationHandler invocationHandler;

	private Map<String, MBeanAttributeInfo> allowedAttributes = Collections.emptyMap();

	private Map<MethodCacheKey, MBeanOperationInfo> allowedOperations = Collections.emptyMap();

	private final Map<Method, String[]> signatureCache = new HashMap<>();

	private final Object preparationMonitor = new Object();


	Set the MBeanServerConnection used to connect to the MBean which all invocations are routed to. /**
	 * Set the {@code MBeanServerConnection} used to connect to the
	 * MBean which all invocations are routed to.
	 */
	public void setServer(MBeanServerConnection server) {
		this.server = server;
	}

	Set the service URL of the remote MBeanServer. /**
	 * Set the service URL of the remote {@code MBeanServer}.
	 */
	public void setServiceUrl(String url) throws MalformedURLException {
		this.serviceUrl = new JMXServiceURL(url);
	}

	Specify the environment for the JMX connector.
See Also: connect.connect(JMXServiceURL, Map)/**
	 * Specify the environment for the JMX connector.
	 * @see javax.management.remote.JMXConnectorFactory#connect(javax.management.remote.JMXServiceURL, java.util.Map)
	 */
	public void setEnvironment(@Nullable Map<String, ?> environment) {
		this.environment = environment;
	}

	Allow Map access to the environment to be set for the connector,
with the option to add or override specific entries.
Useful for specifying entries directly, for example via
"environment[myKey]". This is particularly useful for
adding or overriding entries in child bean definitions.
/**
	 * Allow Map access to the environment to be set for the connector,
	 * with the option to add or override specific entries.
	 * <p>Useful for specifying entries directly, for example via
	 * "environment[myKey]". This is particularly useful for
	 * adding or overriding entries in child bean definitions.
	 */
	@Nullable
	public Map<String, ?> getEnvironment() {
		return this.environment;
	}

	Set the agent id of the MBeanServer to locate. Default is none. If specified, this will result in an attempt being made to locate the attendant MBeanServer, unless the "serviceUrl" property has been set. 
See Also: Specifying the empty String indicates the platform MBeanServer./**
	 * Set the agent id of the {@code MBeanServer} to locate.
	 * <p>Default is none. If specified, this will result in an
	 * attempt being made to locate the attendant MBeanServer, unless
	 * the {@link #setServiceUrl "serviceUrl"} property has been set.
	 * @see javax.management.MBeanServerFactory#findMBeanServer(String)
	 * <p>Specifying the empty String indicates the platform MBeanServer.
	 */
	public void setAgentId(String agentId) {
		this.agentId = agentId;
	}

	Set whether or not the proxy should connect to the MBeanServer at creation time ("true") or the first time it is invoked ("false"). Default is "true". /**
	 * Set whether or not the proxy should connect to the {@code MBeanServer}
	 * at creation time ("true") or the first time it is invoked ("false").
	 * Default is "true".
	 */
	public void setConnectOnStartup(boolean connectOnStartup) {
		this.connectOnStartup = connectOnStartup;
	}

	Set whether to refresh the MBeanServer connection on connect failure.
Default is "false".
Can be turned on to allow for hot restart of the JMX server,
automatically reconnecting and retrying in case of an IOException.
/**
	 * Set whether to refresh the MBeanServer connection on connect failure.
	 * Default is "false".
	 * <p>Can be turned on to allow for hot restart of the JMX server,
	 * automatically reconnecting and retrying in case of an IOException.
	 */
	public void setRefreshOnConnectFailure(boolean refreshOnConnectFailure) {
		this.refreshOnConnectFailure = refreshOnConnectFailure;
	}

	Set the ObjectName of the MBean which calls are routed to, as ObjectName instance or as String. /**
	 * Set the {@code ObjectName} of the MBean which calls are routed to,
	 * as {@code ObjectName} instance or as {@code String}.
	 */
	public void setObjectName(Object objectName) throws MalformedObjectNameException {
		this.objectName = ObjectNameManager.getInstance(objectName);
	}

	Set whether to use strict casing for attributes. Enabled by default.
When using strict casing, a JavaBean property with a getter such as getFoo() translates to an attribute called Foo. With strict casing disabled, getFoo() would translate to just foo. /**
	 * Set whether to use strict casing for attributes. Enabled by default.
	 * <p>When using strict casing, a JavaBean property with a getter such as
	 * {@code getFoo()} translates to an attribute called {@code Foo}.
	 * With strict casing disabled, {@code getFoo()} would translate to just
	 * {@code foo}.
	 */
	public void setUseStrictCasing(boolean useStrictCasing) {
		this.useStrictCasing = useStrictCasing;
	}

	Set the management interface of the target MBean, exposing bean property
setters and getters for MBean attributes and conventional Java methods
for MBean operations.
/**
	 * Set the management interface of the target MBean, exposing bean property
	 * setters and getters for MBean attributes and conventional Java methods
	 * for MBean operations.
	 */
	public void setManagementInterface(@Nullable Class<?> managementInterface) {
		this.managementInterface = managementInterface;
	}

	Return the management interface of the target MBean, or null if none specified. /**
	 * Return the management interface of the target MBean,
	 * or {@code null} if none specified.
	 */
	@Nullable
	protected final Class<?> getManagementInterface() {
		return this.managementInterface;
	}

	@Override
	public void setBeanClassLoader(ClassLoader beanClassLoader) {
		this.beanClassLoader = beanClassLoader;
	}


	Prepares the MBeanServerConnection if the "connectOnStartup" is turned on (which it is by default). /**
	 * Prepares the {@code MBeanServerConnection} if the "connectOnStartup"
	 * is turned on (which it is by default).
	 */
	@Override
	public void afterPropertiesSet() {
		if (this.server != null && this.refreshOnConnectFailure) {
			throw new IllegalArgumentException("'refreshOnConnectFailure' does not work when setting " +
					"a 'server' reference. Prefer 'serviceUrl' etc instead.");
		}
		if (this.connectOnStartup) {
			prepare();
		}
	}

	Ensures that an MBeanServerConnection is configured and attempts to detect a local connection if one is not supplied. /**
	 * Ensures that an {@code MBeanServerConnection} is configured and attempts
	 * to detect a local connection if one is not supplied.
	 */
	public void prepare() {
		synchronized (this.preparationMonitor) {
			if (this.server != null) {
				this.serverToUse = this.server;
			}
			else {
				this.serverToUse = null;
				this.serverToUse = this.connector.connect(this.serviceUrl, this.environment, this.agentId);
			}
			this.invocationHandler = null;
			if (this.useStrictCasing) {
				Assert.state(this.objectName != null, "No ObjectName set");
				// Use the JDK's own MBeanServerInvocationHandler, in particular for native MXBean support.
				this.invocationHandler = new MBeanServerInvocationHandler(this.serverToUse, this.objectName,
						(this.managementInterface != null && JMX.isMXBeanInterface(this.managementInterface)));
			}
			else {
				// Non-strict casing can only be achieved through custom invocation handling.
				// Only partial MXBean support available!
				retrieveMBeanInfo(this.serverToUse);
			}
		}
	}
	Loads the management interface info for the configured MBean into the caches.
This information is used by the proxy when determining whether an invocation matches
a valid operation or attribute on the management interface of the managed resource.
/**
	 * Loads the management interface info for the configured MBean into the caches.
	 * This information is used by the proxy when determining whether an invocation matches
	 * a valid operation or attribute on the management interface of the managed resource.
	 */
	private void retrieveMBeanInfo(MBeanServerConnection server) throws MBeanInfoRetrievalException {
		try {
			MBeanInfo info = server.getMBeanInfo(this.objectName);

			MBeanAttributeInfo[] attributeInfo = info.getAttributes();
			this.allowedAttributes = CollectionUtils.newHashMap(attributeInfo.length);
			for (MBeanAttributeInfo infoEle : attributeInfo) {
				this.allowedAttributes.put(infoEle.getName(), infoEle);
			}

			MBeanOperationInfo[] operationInfo = info.getOperations();
			this.allowedOperations = CollectionUtils.newHashMap(operationInfo.length);
			for (MBeanOperationInfo infoEle : operationInfo) {
				Class<?>[] paramTypes = JmxUtils.parameterInfoToTypes(infoEle.getSignature(), this.beanClassLoader);
				this.allowedOperations.put(new MethodCacheKey(infoEle.getName(), paramTypes), infoEle);
			}
		}
		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.
/**
	 * 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.serverToUse != null);
		}
	}


	Route the invocation to the configured managed resource..
Params: invocation – the MethodInvocation to re-route
Throws: Throwable – an invocation error propagated to the user
See Also: doInvoke
handleConnectFailure
Returns: the value returned as a result of the re-routed invocation/**
	 * Route the invocation to the configured managed resource..
	 * @param invocation the {@code MethodInvocation} to re-route
	 * @return the value returned as a result of the re-routed invocation
	 * @throws Throwable an invocation error propagated to the user
	 * @see #doInvoke
	 * @see #handleConnectFailure
	 */
	@Override
	@Nullable
	public Object invoke(MethodInvocation invocation) throws Throwable {
		// Lazily connect to MBeanServer if necessary.
		synchronized (this.preparationMonitor) {
			if (!isPrepared()) {
				prepare();
			}
		}
		try {
			return doInvoke(invocation);
		}
		catch (MBeanConnectFailureException | IOException ex) {
			return handleConnectFailure(invocation, ex);
		}
	}

	Refresh the connection and retry the MBean invocation if possible.
If not configured to refresh on connect failure, this method
simply rethrows the original exception.
Params: invocation – the invocation that failed
ex – the exception raised on remote invocation
Throws: Throwable – an exception raised by the new invocation,
if it failed as well
See Also: setRefreshOnConnectFailure
doInvoke
Returns: the result value of the new invocation, if succeeded/**
	 * Refresh the connection and retry the MBean invocation if possible.
	 * <p>If not configured to refresh on connect failure, this method
	 * simply rethrows the original exception.
	 * @param invocation the invocation that failed
	 * @param ex the exception raised on remote invocation
	 * @return the result value of the new invocation, if succeeded
	 * @throws Throwable an exception raised by the new invocation,
	 * if it failed as well
	 * @see #setRefreshOnConnectFailure
	 * @see #doInvoke
	 */
	@Nullable
	protected Object handleConnectFailure(MethodInvocation invocation, Exception ex) throws Throwable {
		if (this.refreshOnConnectFailure) {
			String msg = "Could not connect to JMX server - retrying";
			if (logger.isDebugEnabled()) {
				logger.warn(msg, ex);
			}
			else if (logger.isWarnEnabled()) {
				logger.warn(msg);
			}
			prepare();
			return doInvoke(invocation);
		}
		else {
			throw ex;
		}
	}

	Route the invocation to the configured managed resource. Correctly routes JavaBean property access to MBeanServerConnection.get/setAttribute and method invocation to MBeanServerConnection.invoke. 
Params: invocation – the MethodInvocation to re-route
Throws: Throwable – an invocation error propagated to the user
Returns: the value returned as a result of the re-routed invocation/**
	 * Route the invocation to the configured managed resource. Correctly routes JavaBean property
	 * access to {@code MBeanServerConnection.get/setAttribute} and method invocation to
	 * {@code MBeanServerConnection.invoke}.
	 * @param invocation the {@code MethodInvocation} to re-route
	 * @return the value returned as a result of the re-routed invocation
	 * @throws Throwable an invocation error propagated to the user
	 */
	@Nullable
	protected Object doInvoke(MethodInvocation invocation) throws Throwable {
		Method method = invocation.getMethod();
		try {
			Object result;
			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, new MethodParameter(method, -1));
		}
		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 MBeanConnectFailureException("I/O failure during JMX access", ex);
			}
		}
	}

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

		Assert.state(this.serverToUse != null, "No MBeanServerConnection available");

		String attributeName = JmxUtils.getAttributeName(pd, this.useStrictCasing);
		MBeanAttributeInfo inf = 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.serverToUse.getAttribute(this.objectName, attributeName);
			}
			else {
				throw new InvalidInvocationException("Attribute '" + attributeName + "' is not readable");
			}
		}
		else if (invocation.getMethod().equals(pd.getWriteMethod())) {
			if (inf.isWritable()) {
				this.serverToUse.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.
Params: method – the method corresponding to operation on the managed resource.
args – the invocation arguments
Returns: the value returned by the method invocation./**
	 * 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 {
		Assert.state(this.serverToUse != null, "No MBeanServerConnection available");

		MethodCacheKey key = new MethodCacheKey(method.getName(), method.getParameterTypes());
		MBeanOperationInfo info = this.allowedOperations.get(key);
		if (info == null) {
			throw new InvalidInvocationException("Operation '" + method.getName() +
					"' is not exposed on the management interface");
		}

		String[] signature;
		synchronized (this.signatureCache) {
			signature = this.signatureCache.get(method);
			if (signature == null) {
				signature = JmxUtils.getMethodSignature(method);
				this.signatureCache.put(method, signature);
			}
		}

		return this.serverToUse.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.
Params: result – the result object as returned by the MBeanServer
parameter – the method parameter of the proxy method that's been invoked
Returns: the converted result object, or the passed-in object if no conversion
is necessary/**
	 * 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}
	 * @param parameter the method parameter of the proxy method that's been invoked
	 * @return the converted result object, or the passed-in object if no conversion
	 * is necessary
	 */
	@Nullable
	protected Object convertResultValueIfNecessary(@Nullable Object result, MethodParameter parameter) {
		Class<?> targetClass = parameter.getParameterType();
		try {
			if (result == null) {
				return null;
			}
			if (ClassUtils.isAssignableValue(targetClass, result)) {
				return result;
			}
			if (result instanceof CompositeData) {
				Method fromMethod = targetClass.getMethod("from", CompositeData.class);
				return ReflectionUtils.invokeMethod(fromMethod, null, result);
			}
			else if (result instanceof CompositeData[]) {
				CompositeData[] array = (CompositeData[]) result;
				if (targetClass.isArray()) {
					return convertDataArrayToTargetArray(array, targetClass);
				}
				else if (Collection.class.isAssignableFrom(targetClass)) {
					Class<?> elementType =
							ResolvableType.forMethodParameter(parameter).asCollection().resolveGeneric();
					if (elementType != null) {
						return convertDataArrayToTargetCollection(array, targetClass, elementType);
					}
				}
			}
			else if (result instanceof TabularData) {
				Method fromMethod = targetClass.getMethod("from", TabularData.class);
				return ReflectionUtils.invokeMethod(fromMethod, null, result);
			}
			else if (result instanceof TabularData[]) {
				TabularData[] array = (TabularData[]) result;
				if (targetClass.isArray()) {
					return convertDataArrayToTargetArray(array, targetClass);
				}
				else if (Collection.class.isAssignableFrom(targetClass)) {
					Class<?> elementType =
							ResolvableType.forMethodParameter(parameter).asCollection().resolveGeneric();
					if (elementType != null) {
						return convertDataArrayToTargetCollection(array, targetClass, elementType);
					}
				}
			}
			throw new InvocationFailureException(
					"Incompatible result value [" + result + "] for target type [" + targetClass.getName() + "]");
		}
		catch (NoSuchMethodException ex) {
			throw new InvocationFailureException(
					"Could not obtain 'from(CompositeData)' / 'from(TabularData)' method on target type [" +
							targetClass.getName() + "] for conversion of MXBean data structure [" + result + "]");
		}
	}

	private Object convertDataArrayToTargetArray(Object[] array, Class<?> targetClass) throws NoSuchMethodException {
		Class<?> targetType = targetClass.getComponentType();
		Method fromMethod = targetType.getMethod("from", array.getClass().getComponentType());
		Object resultArray = Array.newInstance(targetType, array.length);
		for (int i = 0; i < array.length; i++) {
			Array.set(resultArray, i, ReflectionUtils.invokeMethod(fromMethod, null, array[i]));
		}
		return resultArray;
	}

	private Collection<?> convertDataArrayToTargetCollection(Object[] array, Class<?> collectionType, Class<?> elementType)
			throws NoSuchMethodException {

		Method fromMethod = elementType.getMethod("from", array.getClass().getComponentType());
		Collection<Object> resultColl = CollectionFactory.createCollection(collectionType, Array.getLength(array));
		for (int i = 0; i < array.length; i++) {
			resultColl.add(ReflectionUtils.invokeMethod(fromMethod, null, array[i]));
		}
		return resultColl;
	}


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


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

		private final String name;

		private final Class<?>[] parameterTypes;

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

		@Override
		public boolean equals(@Nullable Object other) {
			if (this == other) {
				return true;
			}
			if (!(other instanceof MethodCacheKey)) {
				return false;
			}
			MethodCacheKey otherKey = (MethodCacheKey) other;
			return (this.name.equals(otherKey.name) && Arrays.equals(this.parameterTypes, otherKey.parameterTypes));
		}

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

		@Override
		public String toString() {
			return this.name + "(" + StringUtils.arrayToCommaDelimitedString(this.parameterTypes) + ")";
		}

		@Override
		public int compareTo(MethodCacheKey other) {
			int result = this.name.compareTo(other.name);
			if (result != 0) {
				return result;
			}
			if (this.parameterTypes.length < other.parameterTypes.length) {
				return -1;
			}
			if (this.parameterTypes.length > other.parameterTypes.length) {
				return 1;
			}
			for (int i = 0; i < this.parameterTypes.length; i++) {
				result = this.parameterTypes[i].getName().compareTo(other.parameterTypes[i].getName());
				if (result != 0) {
					return result;
				}
			}
			return 0;
		}
	}

}
Author:	Rob Harrop, Juergen Hoeller
See Also:	MBeanProxyFactoryBean setConnectOnStartup
Since:	1.2
Params:	invocation – the `MethodInvocation` to re-route
Throws:	Throwable – an invocation error propagated to the user
See Also:	doInvoke handleConnectFailure
Returns:	the value returned as a result of the re-routed invocation
Params:	invocation – the invocation that failed ex – the exception raised on remote invocation
Throws:	Throwable – an exception raised by the new invocation, if it failed as well
See Also:	setRefreshOnConnectFailure doInvoke
Returns:	the result value of the new invocation, if succeeded
Params:	method – the method corresponding to operation on the managed resource. args – the invocation arguments
Returns:	the value returned by the method invocation.
Params:	result – the result object as returned by the `MBeanServer` parameter – the method parameter of the proxy method that's been invoked
Returns:	the converted result object, or the passed-in object if no conversion is necessary
/

org.springframework/ spring-context/ 5.3.3/ org/springframework/jmx/access/MBeanClientInterceptor.java
