ManagedBean.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.tomcat.util.modeler;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import javax.management.AttributeNotFoundException;
import javax.management.DynamicMBean;
import javax.management.InstanceNotFoundException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanConstructorInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanNotificationInfo;
import javax.management.MBeanOperationInfo;
import javax.management.ReflectionException;
import javax.management.RuntimeOperationsException;
import javax.management.ServiceNotFoundException;
import org.apache.tomcat.util.buf.StringUtils;
import org.apache.tomcat.util.buf.StringUtils.Function;
/**
* <p>Internal configuration information for a managed bean (MBean)
* descriptor.</p>
*
* @author Craig R. McClanahan
*/
public class ManagedBean implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private static final String BASE_MBEAN = "org.apache.tomcat.util.modeler.BaseModelMBean";
// ----------------------------------------------------- Instance Variables
static final Class<?>[] NO_ARGS_PARAM_SIG = new Class[0];
private final ReadWriteLock mBeanInfoLock = new ReentrantReadWriteLock();
/**
* The <code>ModelMBeanInfo</code> object that corresponds
* to this <code>ManagedBean</code> instance.
*/
private transient volatile MBeanInfo info = null;
private Map<String,AttributeInfo> attributes = new HashMap<>();
private Map<String,OperationInfo> operations = new HashMap<>();
protected String className = BASE_MBEAN;
protected String description = null;
protected String domain = null;
protected String group = null;
protected String name = null;
private NotificationInfo notifications[] = new NotificationInfo[0];
protected String type = null;
/**
* Constructor. Will add default attributes.
*/
public ManagedBean() {
AttributeInfo ai=new AttributeInfo();
ai.setName("modelerType");
ai.setDescription("Type of the modeled resource. Can be set only once");
ai.setType("java.lang.String");
ai.setWriteable(false);
addAttribute(ai);
}
// ------------------------------------------------------------- Properties
/**
* @return the collection of attributes for this MBean.
*/
public AttributeInfo[] getAttributes() {
return attributes.values().toArray(new AttributeInfo[0]);
}
/**
* The fully qualified name of the Java class of the MBean
* described by this descriptor. If not specified, the standard JMX
* class (<code>javax.management.modelmbean.RequiredModeLMBean</code>)
* will be utilized.
* @return the class name
*/
public String getClassName() {
return this.className;
}
public void setClassName(String className) {
mBeanInfoLock.writeLock().lock();
try {
this.className = className;
this.info = null;
} finally {
mBeanInfoLock.writeLock().unlock();
}
}
/**
* @return the human-readable description of this MBean.
*/
public String getDescription() {
return this.description;
}
public void setDescription(String description) {
mBeanInfoLock.writeLock().lock();
try {
this.description = description;
this.info = null;
} finally {
mBeanInfoLock.writeLock().unlock();
}
}
/**
* @return the (optional) <code>ObjectName</code> domain in which
* this MBean should be registered in the MBeanServer.
*/
public String getDomain() {
return this.domain;
}
public void setDomain(String domain) {
this.domain = domain;
}
/**
* @return the (optional) group to which this MBean belongs.
*/
public String getGroup() {
return this.group;
}
public void setGroup(String group) {
this.group = group;
}
/**
* @return the name of this managed bean, which must be unique
* among all MBeans managed by a particular MBeans server.
*/
public String getName() {
return this.name;
}
public void setName(String name) {
mBeanInfoLock.writeLock().lock();
try {
this.name = name;
this.info = null;
} finally {
mBeanInfoLock.writeLock().unlock();
}
}
/**
* @return the collection of notifications for this MBean.
*/
public NotificationInfo[] getNotifications() {
return this.notifications;
}
/**
* @return the collection of operations for this MBean.
*/
public OperationInfo[] getOperations() {
return operations.values().toArray(new OperationInfo[0]);
}
/**
* @return the fully qualified name of the Java class of the resource
* implementation class described by the managed bean described
* by this descriptor.
*/
public String getType() {
return this.type;
}
public void setType(String type) {
mBeanInfoLock.writeLock().lock();
try {
this.type = type;
this.info = null;
} finally {
mBeanInfoLock.writeLock().unlock();
}
}
// --------------------------------------------------------- Public Methods
/**
* Add a new attribute to the set of attributes for this MBean.
*
* @param attribute The new attribute descriptor
*/
public void addAttribute(AttributeInfo attribute) {
attributes.put(attribute.getName(), attribute);
}
/**
* Add a new notification to the set of notifications for this MBean.
*
* @param notification The new notification descriptor
*/
public void addNotification(NotificationInfo notification) {
mBeanInfoLock.writeLock().lock();
try {
NotificationInfo results[] =
new NotificationInfo[notifications.length + 1];
System.arraycopy(notifications, 0, results, 0,
notifications.length);
results[notifications.length] = notification;
notifications = results;
this.info = null;
} finally {
mBeanInfoLock.writeLock().unlock();
}
}
/**
* Add a new operation to the set of operations for this MBean.
*
* @param operation The new operation descriptor
*/
public void addOperation(OperationInfo operation) {
operations.put(createOperationKey(operation), operation);
}
/**
* Create and return a <code>ModelMBean</code> that has been
* preconfigured with the <code>ModelMBeanInfo</code> information
* for this managed bean, and is associated with the specified
* managed object instance. The returned <code>ModelMBean</code>
* will <strong>NOT</strong> have been registered with our
* <code>MBeanServer</code>.
*
* @param instance Instanced of the managed object, or <code>null</code>
* for no associated instance
* @return the MBean
* @exception InstanceNotFoundException if the managed resource
* object cannot be found
* @exception MBeanException if a problem occurs instantiating the
* <code>ModelMBean</code> instance
* @exception RuntimeOperationsException if a JMX runtime error occurs
*/
public DynamicMBean createMBean(Object instance)
throws InstanceNotFoundException,
MBeanException, RuntimeOperationsException {
BaseModelMBean mbean = null;
// Load the ModelMBean implementation class
if(getClassName().equals(BASE_MBEAN)) {
// Skip introspection
mbean = new BaseModelMBean();
} else {
Class<?> clazz = null;
Exception ex = null;
try {
clazz = Class.forName(getClassName());
} catch (Exception e) {
}
if( clazz==null ) {
try {
ClassLoader cl= Thread.currentThread().getContextClassLoader();
if ( cl != null) {
clazz= cl.loadClass(getClassName());
}
} catch (Exception e) {
ex=e;
}
}
if( clazz==null) {
throw new MBeanException
(ex, "Cannot load ModelMBean class " + getClassName());
}
try {
// Stupid - this will set the default minfo first....
mbean = (BaseModelMBean) clazz.getConstructor().newInstance();
} catch (RuntimeOperationsException e) {
throw e;
} catch (Exception e) {
throw new MBeanException
(e, "Cannot instantiate ModelMBean of class " +
getClassName());
}
}
mbean.setManagedBean(this);
// Set the managed resource (if any)
try {
if (instance != null) {
mbean.setManagedResource(instance, "ObjectReference");
}
} catch (InstanceNotFoundException e) {
throw e;
}
return mbean;
}
/**
* Create and return a <code>ModelMBeanInfo</code> object that
* describes this entire managed bean.
* @return the MBean info
*/
MBeanInfo getMBeanInfo() {
// Return our cached information (if any)
mBeanInfoLock.readLock().lock();
try {
if (info != null) {
return info;
}
} finally {
mBeanInfoLock.readLock().unlock();
}
mBeanInfoLock.writeLock().lock();
try {
if (info == null) {
// Create subordinate information descriptors as required
AttributeInfo attrs[] = getAttributes();
MBeanAttributeInfo attributes[] =
new MBeanAttributeInfo[attrs.length];
for (int i = 0; i < attrs.length; i++) {
attributes[i] = attrs[i].createAttributeInfo();
}
OperationInfo opers[] = getOperations();
MBeanOperationInfo operations[] =
new MBeanOperationInfo[opers.length];
for (int i = 0; i < opers.length; i++) {
operations[i] = opers[i].createOperationInfo();
}
NotificationInfo notifs[] = getNotifications();
MBeanNotificationInfo notifications[] =
new MBeanNotificationInfo[notifs.length];
for (int i = 0; i < notifs.length; i++) {
notifications[i] = notifs[i].createNotificationInfo();
}
// Construct and return a new ModelMBeanInfo object
info = new MBeanInfo(getClassName(),
getDescription(),
attributes,
new MBeanConstructorInfo[] {},
operations,
notifications);
}
return info;
} finally {
mBeanInfoLock.writeLock().unlock();
}
}
/**
* Return a string representation of this managed bean.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder("ManagedBean[");
sb.append("name=");
sb.append(name);
sb.append(", className=");
sb.append(className);
sb.append(", description=");
sb.append(description);
if (group != null) {
sb.append(", group=");
sb.append(group);
}
sb.append(", type=");
sb.append(type);
sb.append(']');
return sb.toString();
}
Method getGetter(String aname, BaseModelMBean mbean, Object resource)
throws AttributeNotFoundException, ReflectionException {
Method m = null;
AttributeInfo attrInfo = attributes.get(aname);
// Look up the actual operation to be used
if (attrInfo == null) {
throw new AttributeNotFoundException(" Cannot find attribute " + aname + " for " + resource);
}
String getMethod = attrInfo.getGetMethod();
if (getMethod == null) {
throw new AttributeNotFoundException("Cannot find attribute " + aname + " get method name");
}
Object object = null;
NoSuchMethodException exception = null;
try {
object = mbean;
m = object.getClass().getMethod(getMethod, NO_ARGS_PARAM_SIG);
} catch (NoSuchMethodException e) {
exception = e;
}
if (m== null && resource != null) {
try {
object = resource;
m = object.getClass().getMethod(getMethod, NO_ARGS_PARAM_SIG);
exception=null;
} catch (NoSuchMethodException e) {
exception = e;
}
}
if (exception != null) {
throw new ReflectionException(exception,
"Cannot find getter method " + getMethod);
}
return m;
}
public Method getSetter(String aname, BaseModelMBean bean, Object resource)
throws AttributeNotFoundException, ReflectionException {
Method m = null;
AttributeInfo attrInfo = attributes.get(aname);
if (attrInfo == null) {
throw new AttributeNotFoundException(" Cannot find attribute " + aname);
}
// Look up the actual operation to be used
String setMethod = attrInfo.getSetMethod();
if (setMethod == null) {
throw new AttributeNotFoundException("Cannot find attribute " + aname + " set method name");
}
String argType=attrInfo.getType();
Class<?> signature[] =
new Class[] { BaseModelMBean.getAttributeClass( argType ) };
Object object = null;
NoSuchMethodException exception = null;
try {
object = bean;
m = object.getClass().getMethod(setMethod, signature);
} catch (NoSuchMethodException e) {
exception = e;
}
if (m == null && resource != null) {
try {
object = resource;
m = object.getClass().getMethod(setMethod, signature);
exception=null;
} catch (NoSuchMethodException e) {
exception = e;
}
}
if (exception != null) {
throw new ReflectionException(exception,
"Cannot find setter method " + setMethod +
" " + resource);
}
return m;
}
public Method getInvoke(String aname, Object[] params, String[] signature, BaseModelMBean bean, Object resource)
throws MBeanException, ReflectionException {
Method method = null;
if (params == null) {
params = new Object[0];
}
if (signature == null) {
signature = new String[0];
}
if (params.length != signature.length) {
throw new RuntimeOperationsException(
new IllegalArgumentException(
"Inconsistent arguments and signature"),
"Inconsistent arguments and signature");
}
// Acquire the ModelMBeanOperationInfo information for
// the requested operation
OperationInfo opInfo =
operations.get(createOperationKey(aname, signature));
if (opInfo == null) {
throw new MBeanException(new ServiceNotFoundException(
"Cannot find operation " + aname),
"Cannot find operation " + aname);
}
// Prepare the signature required by Java reflection APIs
// FIXME - should we use the signature from opInfo?
Class<?> types[] = new Class[signature.length];
for (int i = 0; i < signature.length; i++) {
types[i] = BaseModelMBean.getAttributeClass(signature[i]);
}
// Locate the method to be invoked, either in this MBean itself
// or in the corresponding managed resource
// FIXME - Accessible methods in superinterfaces?
Object object = null;
Exception exception = null;
try {
object = bean;
method = object.getClass().getMethod(aname, types);
} catch (NoSuchMethodException e) {
exception = e;
}
try {
if ((method == null) && (resource != null)) {
object = resource;
method = object.getClass().getMethod(aname, types);
}
} catch (NoSuchMethodException e) {
exception = e;
}
if (method == null) {
throw new ReflectionException(exception, "Cannot find method "
+ aname + " with this signature");
}
return method;
}
private String createOperationKey(OperationInfo operation) {
StringBuilder key = new StringBuilder(operation.getName());
key.append('(');
StringUtils.join(operation.getSignature(), ',', new Function<ParameterInfo>() {
@Override public String apply(ParameterInfo t) { return t.getType(); }}, key);
key.append(')');
return key.toString().intern();
}
private String createOperationKey(String methodName, String[] parameterTypes) {
StringBuilder key = new StringBuilder(methodName);
key.append('(');
StringUtils.join(parameterTypes, ',', key);
key.append(')');
return key.toString().intern();
}
}