/*
* Copyright 2002-2007 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
*
* 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.springframework.jmx.access;
import java.beans.PropertyDescriptor;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.util.Arrays;
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.MBeanServer;
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.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
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.JdkVersion;
import org.springframework.jmx.MBeanServerNotFoundException;
import org.springframework.jmx.support.JmxUtils;
import org.springframework.jmx.support.ObjectNameManager;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
/**
* {@link org.aopalliance.intercept.MethodInterceptor} that routes calls to an
* MBean running on the supplied <code>MBeanServerConnection</code>.
* Works for both local and remote <code>MBeanServerConnection</code>s.
*
* <p>By default, the <code>MBeanClientInterceptor</code> will connect to the
* <code>MBeanServer</code> and cache MBean metadata at startup. This can
* be undesirable when running against a remote <code>MBeanServer</code>
* 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>Requires JMX 1.2's <code>MBeanServerConnection</code> feature.
* As a consequence, this class will not work on JMX 1.0.
*
* <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 */
protected final Log logger = LogFactory.getLog(getClass());
private MBeanServerConnection server;
private JMXServiceURL serviceUrl;
private String agentId;
private boolean connectOnStartup = true;
private ObjectName objectName;
private boolean useStrictCasing = true;
private Class managementInterface;
private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
private JMXConnector connector;
private MBeanServerInvocationHandler invocationHandler;
private Map allowedAttributes;
private Map allowedOperations;
private final Map signatureCache = new HashMap();
private final Object preparationMonitor = new Object();
/**
* Set the <code>MBeanServerConnection</code> 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 <code>MBeanServer</code>.
*/
public void setServiceUrl(String url) throws MalformedURLException {
this.serviceUrl = new JMXServiceURL(url);
}
/**
* Set the agent id of the <code>MBeanServer</code> 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)
*/
public void setAgentId(String agentId) {
this.agentId = agentId;
}
/**
* Set whether or not the proxy should connect to the <code>MBeanServer</code>
* at creation time ("true") or the first time it is invoked ("false").
* Default is "true".
*/
public void setConnectOnStartup(boolean connectOnStartup) {
this.connectOnStartup = connectOnStartup;
}
/**
* Set the <code>ObjectName</code> of the MBean which calls are routed to,
* as <code>ObjectName</code> instance or as <code>String</code>.
*/
public void setObjectName(Object objectName) throws MalformedObjectNameException {
this.objectName = ObjectNameManager.getInstance(objectName);
}
/**
* 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()</code> translates to an attribute called <code>Foo</code>.
* With strict casing disabled, <code>getFoo()</code> would translate to just
* <code>foo</code>.
*/
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.
*/
public void setManagementInterface(Class managementInterface) {
this.managementInterface = managementInterface;
}
/**
* Return the management interface of the target MBean,
* or <code>null</code> if none specified.
*/
protected final Class getManagementInterface() {
return this.managementInterface;
}
public void setBeanClassLoader(ClassLoader beanClassLoader) {
this.beanClassLoader = beanClassLoader;
}
/**
* Prepares the <code>MBeanServerConnection</code> if the "connectOnStartup"
* is turned on (which it is by default).
*/
public void afterPropertiesSet() {
if (this.connectOnStartup) {
prepare();
}
}
/**
* Ensures that an <code>MBeanServerConnection</code> is configured and attempts
* to detect a local connection if one is not supplied.
*/
public void prepare() {
synchronized (this.preparationMonitor) {
if (this.server == null) {
connect();
}
this.invocationHandler = null;
if (this.useStrictCasing) {
// Use the JDK's own MBeanServerInvocationHandler,
// in particular for native MXBean support on Java 6.
if (JdkVersion.isAtLeastJava16()) {
this.invocationHandler =
new MBeanServerInvocationHandler(this.server, this.objectName,
(this.managementInterface != null && JMX.isMXBeanInterface(this.managementInterface)));
}
else {
this.invocationHandler = new MBeanServerInvocationHandler(this.server, this.objectName);
}
}
else {
// Non-strict asing can only be achieved through custom
// invocation handling. Only partial MXBean support available!
retrieveMBeanInfo();
}
}
}
/**
* Connects to the remote <code>MBeanServer</code> using the configured <code>JMXServiceURL</code>.
* @see #setServiceUrl(String)
* @see #setConnectOnStartup(boolean)
*/
private void connect() throws MBeanServerNotFoundException {
if (this.serviceUrl != null) {
if (logger.isDebugEnabled()) {
logger.debug("Connecting to remote MBeanServer at URL [" + this.serviceUrl + "]");
}
try {
this.connector = JMXConnectorFactory.connect(this.serviceUrl);
this.server = this.connector.getMBeanServerConnection();
}
catch (IOException ex) {
throw new MBeanServerNotFoundException(
"Could not connect to remote MBeanServer at URL [" + this.serviceUrl + "]", ex);
}
}
else {
logger.debug("Attempting to locate local MBeanServer");
this.server = locateMBeanServer(this.agentId);
}
}
/**
* Attempt to locate an existing <code>MBeanServer</code>.
* Called if no {@link #setServiceUrl "serviceUrl"} was specified.
* <p>The default implementation attempts to find an <code>MBeanServer</code> using
* a standard lookup. Subclasses may override to add additional location logic.
* @param agentId the agent identifier of the MBeanServer to retrieve.
* If this parameter is <code>null</code>, all registered MBeanServers are
* considered.
* @return the <code>MBeanServer</code> if found
* @throws org.springframework.jmx.MBeanServerNotFoundException
* if no <code>MBeanServer</code> could be found
* @see JmxUtils#locateMBeanServer(String)
* @see javax.management.MBeanServerFactory#findMBeanServer(String)
*/
protected MBeanServer locateMBeanServer(String agentId) throws MBeanServerNotFoundException {
return JmxUtils.locateMBeanServer(agentId);
}
/**
* 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() throws MBeanInfoRetrievalException {
try {
MBeanInfo info = this.server.getMBeanInfo(this.objectName);
// get attributes
MBeanAttributeInfo[] attributeInfo = info.getAttributes();
this.allowedAttributes = new HashMap(attributeInfo.length);
for (int x = 0; x < attributeInfo.length; x++) {
this.allowedAttributes.put(attributeInfo[x].getName(), attributeInfo[x]);
}
// get operations
MBeanOperationInfo[] operationInfo = info.getOperations();
this.allowedOperations = new HashMap(operationInfo.length);
for (int x = 0; x < operationInfo.length; x++) {
MBeanOperationInfo opInfo = operationInfo[x];
Class[] paramTypes = JmxUtils.parameterInfoToTypes(opInfo.getSignature(), this.beanClassLoader);
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 + "]");
}
}
/**
* Closes any <code>JMXConnector</code> that may be managed by this interceptor.
*/
public void destroy() throws Exception {
if (this.connector != null) {
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();
}
}
}