private Object getAttribute(ObjectName objName, String attrName)
throws MBeanException, InstanceNotFoundException, AttributeNotFoundException,
ReflectionException, IOException {
final NameValueMap values = getCachedAttributes(objName, Collections.singleton(attrName));
Object value = values.get(attrName);
if (value != null || values.containsKey(attrName)) {
return value;
}
// Not in cache, presumably because it was omitted from the
// getAttributes result because of an exception. Following
// call will probably provoke the same exception.
return conn.getAttribute(objName, attrName);
}
public class ProxyClient implements JConsoleContext {
private ConnectionState connectionState = ConnectionState.DISCONNECTED;
// The SwingPropertyChangeSupport will fire events on the EDT
private SwingPropertyChangeSupport propertyChangeSupport =
new SwingPropertyChangeSupport(this, true);
private static Map<String, ProxyClient> cache =
Collections.synchronizedMap(new HashMap<String, ProxyClient>());
private volatile boolean isDead = true;
private String hostName = null;
private int port = 0;
private String userName = null;
private String password = null;
private boolean hasPlatformMXBeans = false;
private boolean hasHotSpotDiagnosticMXBean = false;
private boolean hasCompilationMXBean = false;
private boolean supportsLockUsage = false;
// REVISIT: VMPanel and other places relying using getUrl().
// set only if it's created for local monitoring
private LocalVirtualMachine lvm;
// set only if it's created from a given URL via the Advanced tab
private String advancedUrl = null;
private JMXServiceURL jmxUrl = null;
private MBeanServerConnection mbsc = null;
private SnapshotMBeanServerConnection server = null;
private JMXConnector jmxc = null;
private RMIServer stub = null;
private static final SslRMIClientSocketFactory sslRMIClientSocketFactory =
new SslRMIClientSocketFactory();
private String registryHostName = null;
private int registryPort = 0;
private boolean vmConnector = false;
private boolean sslRegistry = false;
private boolean sslStub = false;
private final String connectionName;
private final String displayName;
private ClassLoadingMXBean classLoadingMBean = null;
private CompilationMXBean compilationMBean = null;
private MemoryMXBean memoryMBean = null;
private OperatingSystemMXBean operatingSystemMBean = null;
private RuntimeMXBean runtimeMBean = null;
private ThreadMXBean threadMBean = null;
private com.sun.management.OperatingSystemMXBean sunOperatingSystemMXBean = null;
private HotSpotDiagnosticMXBean hotspotDiagnosticMXBean = null;
private List<MemoryPoolProxy> memoryPoolProxies = null;
private List<GarbageCollectorMXBean> garbageCollectorMBeans = null;
private static final String HOTSPOT_DIAGNOSTIC_MXBEAN_NAME =
"com.sun.management:type=HotSpotDiagnostic";
private ProxyClient(String hostName, int port, String userName, String password)
throws IOException {
this.connectionName = getConnectionName(hostName, port, userName);
this.displayName = connectionName;
if (hostName.equals("localhost") && port == 0) {
// Monitor self
this.hostName = hostName;
this.port = port;
} else {
// Create an RMI connector client and connect it to
// the RMI connector server
final String urlPath = "/jndi/rmi://" + hostName + ":" + port + "/jmxrmi";
JMXServiceURL url = new JMXServiceURL("rmi", "", 0, urlPath);
setParameters(url, userName, password);
vmConnector = true;
registryHostName = hostName;
registryPort = port;
checkSslConfig();
}
}
private ProxyClient(String url, String userName, String password) throws IOException {
this.advancedUrl = url;
this.connectionName = getConnectionName(url, userName);
this.displayName = connectionName;
setParameters(new JMXServiceURL(url), userName, password);
}
private ProxyClient(LocalVirtualMachine lvm) throws IOException {
this.lvm = lvm;
this.connectionName = getConnectionName(lvm);
this.displayName = "pid: " + lvm.vmid() + " " + lvm.displayName();
}
private void setParameters(JMXServiceURL url, String userName, String password) {
this.jmxUrl = url;
this.hostName = jmxUrl.getHost();
this.port = jmxUrl.getPort();
this.userName = userName;
this.password = password;
}
private static void checkStub(Remote stub, Class<? extends Remote> stubClass) {
// Check remote stub is from the expected class.
//
if (stub.getClass() != stubClass) {
if (!Proxy.isProxyClass(stub.getClass())) {
throw new SecurityException("Expecting a " + stubClass.getName() + " stub!");
} else {
InvocationHandler handler = Proxy.getInvocationHandler(stub);
if (handler.getClass() != RemoteObjectInvocationHandler.class) {
throw new SecurityException(
"Expecting a dynamic proxy instance with a "
+ RemoteObjectInvocationHandler.class.getName()
+ " invocation handler!");
} else {
stub = (Remote) handler;
}
}
}
// Check RemoteRef in stub is from the expected class
// "sun.rmi.server.UnicastRef2".
//
RemoteRef ref = ((RemoteObject) stub).getRef();
if (ref.getClass() != UnicastRef2.class) {
throw new SecurityException(
"Expecting a " + UnicastRef2.class.getName() + " remote reference in stub!");
}
// Check RMIClientSocketFactory in stub is from the expected class
// "javax.rmi.ssl.SslRMIClientSocketFactory".
//
LiveRef liveRef = ((UnicastRef2) ref).getLiveRef();
RMIClientSocketFactory csf = liveRef.getClientSocketFactory();
if (csf == null || csf.getClass() != SslRMIClientSocketFactory.class) {
throw new SecurityException(
"Expecting a "
+ SslRMIClientSocketFactory.class.getName()
+ " RMI client socket factory in stub!");
}
}
private static final String rmiServerImplStubClassName =
"javax.management.remote.rmi.RMIServerImpl_Stub";
private static final Class<? extends Remote> rmiServerImplStubClass;
static {
// FIXME: RMIServerImpl_Stub is generated at build time
// after jconsole is built. We need to investigate if
// the Makefile can be fixed to build jconsole in the
// right order. As a workaround for now, we dynamically
// load RMIServerImpl_Stub class instead of statically
// referencing it.
Class<? extends Remote> serverStubClass = null;
try {
serverStubClass = Class.forName(rmiServerImplStubClassName).asSubclass(Remote.class);
} catch (ClassNotFoundException e) {
// should never reach here
throw (InternalError) new InternalError(e.getMessage()).initCause(e);
}
rmiServerImplStubClass = serverStubClass;
}
private void checkSslConfig() throws IOException {
// Get the reference to the RMI Registry and lookup RMIServer stub
//
Registry registry;
try {
registry =
LocateRegistry.getRegistry(registryHostName, registryPort, sslRMIClientSocketFactory);
try {
stub = (RMIServer) registry.lookup("jmxrmi");
} catch (NotBoundException nbe) {
throw (IOException) new IOException(nbe.getMessage()).initCause(nbe);
}
sslRegistry = true;
} catch (IOException e) {
registry = LocateRegistry.getRegistry(registryHostName, registryPort);
try {
stub = (RMIServer) registry.lookup("jmxrmi");
} catch (NotBoundException nbe) {
throw (IOException) new IOException(nbe.getMessage()).initCause(nbe);
}
sslRegistry = false;
}
// Perform the checks for secure stub
//
try {
checkStub(stub, rmiServerImplStubClass);
sslStub = true;
} catch (SecurityException e) {
sslStub = false;
}
}
/**
* Returns true if the underlying RMI registry is SSL-protected.
*
* @exception UnsupportedOperationException If this {@code ProxyClient} does not denote a JMX
* connector for a JMX VM agent.
*/
public boolean isSslRmiRegistry() {
// Check for VM connector
//
if (!isVmConnector()) {
throw new UnsupportedOperationException(
"ProxyClient.isSslRmiRegistry() is only supported if this "
+ "ProxyClient is a JMX connector for a JMX VM agent");
}
return sslRegistry;
}
/**
* Returns true if the retrieved RMI stub is SSL-protected.
*
* @exception UnsupportedOperationException If this {@code ProxyClient} does not denote a JMX
* connector for a JMX VM agent.
*/
public boolean isSslRmiStub() {
// Check for VM connector
//
if (!isVmConnector()) {
throw new UnsupportedOperationException(
"ProxyClient.isSslRmiStub() is only supported if this "
+ "ProxyClient is a JMX connector for a JMX VM agent");
}
return sslStub;
}
/** Returns true if this {@code ProxyClient} denotes a JMX connector for a JMX VM agent. */
public boolean isVmConnector() {
return vmConnector;
}
private void setConnectionState(ConnectionState state) {
ConnectionState oldState = this.connectionState;
this.connectionState = state;
propertyChangeSupport.firePropertyChange(CONNECTION_STATE_PROPERTY, oldState, state);
}
public ConnectionState getConnectionState() {
return this.connectionState;
}
void flush() {
if (server != null) {
server.flush();
}
}
void connect(boolean requireSSL) {
setConnectionState(ConnectionState.CONNECTING);
try {
tryConnect(requireSSL);
setConnectionState(ConnectionState.CONNECTED);
} catch (Exception e) {
if (JConsole.isDebug()) {
e.printStackTrace();
}
setConnectionState(ConnectionState.DISCONNECTED);
}
}
private void tryConnect(boolean requireRemoteSSL) throws IOException {
if (jmxUrl == null && "localhost".equals(hostName) && port == 0) {
// Monitor self
this.jmxc = null;
this.mbsc = ManagementFactory.getPlatformMBeanServer();
this.server = Snapshot.newSnapshot(mbsc);
} else {
// Monitor another process
if (lvm != null) {
if (!lvm.isManageable()) {
lvm.startManagementAgent();
if (!lvm.isManageable()) {
// FIXME: what to throw
throw new IOException(lvm + "not manageable");
}
}
if (this.jmxUrl == null) {
this.jmxUrl = new JMXServiceURL(lvm.connectorAddress());
}
}
Map<String, Object> env = new HashMap<String, Object>();
if (requireRemoteSSL) {
env.put("jmx.remote.x.check.stub", "true");
}
// Need to pass in credentials ?
if (userName == null && password == null) {
if (isVmConnector()) {
// Check for SSL config on reconnection only
if (stub == null) {
checkSslConfig();
}
this.jmxc = new RMIConnector(stub, null);
jmxc.connect(env);
} else {
this.jmxc = JMXConnectorFactory.connect(jmxUrl, env);
}
} else {
env.put(JMXConnector.CREDENTIALS, new String[] {userName, password});
if (isVmConnector()) {
// Check for SSL config on reconnection only
if (stub == null) {
checkSslConfig();
}
this.jmxc = new RMIConnector(stub, null);
jmxc.connect(env);
} else {
this.jmxc = JMXConnectorFactory.connect(jmxUrl, env);
}
}
this.mbsc = jmxc.getMBeanServerConnection();
this.server = Snapshot.newSnapshot(mbsc);
}
this.isDead = false;
try {
ObjectName on = new ObjectName(THREAD_MXBEAN_NAME);
this.hasPlatformMXBeans = server.isRegistered(on);
this.hasHotSpotDiagnosticMXBean =
server.isRegistered(new ObjectName(HOTSPOT_DIAGNOSTIC_MXBEAN_NAME));
// check if it has 6.0 new APIs
if (this.hasPlatformMXBeans) {
MBeanOperationInfo[] mopis = server.getMBeanInfo(on).getOperations();
// look for findDeadlockedThreads operations;
for (MBeanOperationInfo op : mopis) {
if (op.getName().equals("findDeadlockedThreads")) {
this.supportsLockUsage = true;
break;
}
}
on = new ObjectName(COMPILATION_MXBEAN_NAME);
this.hasCompilationMXBean = server.isRegistered(on);
}
} catch (MalformedObjectNameException e) {
// should not reach here
throw new InternalError(e.getMessage());
} catch (IntrospectionException e) {
InternalError ie = new InternalError(e.getMessage());
ie.initCause(e);
throw ie;
} catch (InstanceNotFoundException e) {
InternalError ie = new InternalError(e.getMessage());
ie.initCause(e);
throw ie;
} catch (ReflectionException e) {
InternalError ie = new InternalError(e.getMessage());
ie.initCause(e);
throw ie;
}
if (hasPlatformMXBeans) {
// WORKAROUND for bug 5056632
// Check if the access role is correct by getting a RuntimeMXBean
getRuntimeMXBean();
}
}
/** Gets a proxy client for a given local virtual machine. */
public static ProxyClient getProxyClient(LocalVirtualMachine lvm) throws IOException {
final String key = getCacheKey(lvm);
ProxyClient proxyClient = cache.get(key);
if (proxyClient == null) {
proxyClient = new ProxyClient(lvm);
cache.put(key, proxyClient);
}
return proxyClient;
}
public static String getConnectionName(LocalVirtualMachine lvm) {
return Integer.toString(lvm.vmid());
}
private static String getCacheKey(LocalVirtualMachine lvm) {
return Integer.toString(lvm.vmid());
}
/** Gets a proxy client for a given JMXServiceURL. */
public static ProxyClient getProxyClient(String url, String userName, String password)
throws IOException {
final String key = getCacheKey(url, userName, password);
ProxyClient proxyClient = cache.get(key);
if (proxyClient == null) {
proxyClient = new ProxyClient(url, userName, password);
cache.put(key, proxyClient);
}
return proxyClient;
}
public static String getConnectionName(String url, String userName) {
if (userName != null && userName.length() > 0) {
return userName + "@" + url;
} else {
return url;
}
}
private static String getCacheKey(String url, String userName, String password) {
return (url == null ? "" : url)
+ ":"
+ (userName == null ? "" : userName)
+ ":"
+ (password == null ? "" : password);
}
/** Gets a proxy client for a given "hostname:port". */
public static ProxyClient getProxyClient(
String hostName, int port, String userName, String password) throws IOException {
final String key = getCacheKey(hostName, port, userName, password);
ProxyClient proxyClient = cache.get(key);
if (proxyClient == null) {
proxyClient = new ProxyClient(hostName, port, userName, password);
cache.put(key, proxyClient);
}
return proxyClient;
}
public static String getConnectionName(String hostName, int port, String userName) {
String name = hostName + ":" + port;
if (userName != null && userName.length() > 0) {
return userName + "@" + name;
} else {
return name;
}
}
private static String getCacheKey(String hostName, int port, String userName, String password) {
return (hostName == null ? "" : hostName)
+ ":"
+ port
+ ":"
+ (userName == null ? "" : userName)
+ ":"
+ (password == null ? "" : password);
}
public String connectionName() {
return connectionName;
}
public String getDisplayName() {
return displayName;
}
public String toString() {
if (!isConnected()) {
return Resources.format(Messages.CONNECTION_NAME__DISCONNECTED_, displayName);
} else {
return displayName;
}
}
public MBeanServerConnection getMBeanServerConnection() {
return mbsc;
}
public SnapshotMBeanServerConnection getSnapshotMBeanServerConnection() {
return server;
}
public String getUrl() {
return advancedUrl;
}
public String getHostName() {
return hostName;
}
public int getPort() {
return port;
}
public int getVmid() {
return (lvm != null) ? lvm.vmid() : 0;
}
public String getUserName() {
return userName;
}
public String getPassword() {
return password;
}
public void disconnect() {
// Reset remote stub
stub = null;
// Close MBeanServer connection
if (jmxc != null) {
try {
jmxc.close();
} catch (IOException e) {
// Ignore ???
}
}
// Reset platform MBean references
classLoadingMBean = null;
compilationMBean = null;
memoryMBean = null;
operatingSystemMBean = null;
runtimeMBean = null;
threadMBean = null;
sunOperatingSystemMXBean = null;
garbageCollectorMBeans = null;
// Set connection state to DISCONNECTED
if (!isDead) {
isDead = true;
setConnectionState(ConnectionState.DISCONNECTED);
}
}
/** Returns the list of domains in which any MBean is currently registered. */
public String[] getDomains() throws IOException {
return server.getDomains();
}
/**
* Returns a map of MBeans with ObjectName as the key and MBeanInfo value of a given domain. If
* domain is <tt>null</tt>, all MBeans are returned. If no MBean found, an empty map is returned.
*/
public Map<ObjectName, MBeanInfo> getMBeans(String domain) throws IOException {
ObjectName name = null;
if (domain != null) {
try {
name = new ObjectName(domain + ":*");
} catch (MalformedObjectNameException e) {
// should not reach here
assert (false);
}
}
Set<ObjectName> mbeans = server.queryNames(name, null);
Map<ObjectName, MBeanInfo> result = new HashMap<ObjectName, MBeanInfo>(mbeans.size());
Iterator<ObjectName> iterator = mbeans.iterator();
while (iterator.hasNext()) {
Object object = iterator.next();
if (object instanceof ObjectName) {
ObjectName o = (ObjectName) object;
try {
MBeanInfo info = server.getMBeanInfo(o);
result.put(o, info);
} catch (IntrospectionException e) {
// TODO: should log the error
} catch (InstanceNotFoundException e) {
// TODO: should log the error
} catch (ReflectionException e) {
// TODO: should log the error
}
}
}
return result;
}
/** Returns a list of attributes of a named MBean. */
public AttributeList getAttributes(ObjectName name, String[] attributes) throws IOException {
AttributeList list = null;
try {
list = server.getAttributes(name, attributes);
} catch (InstanceNotFoundException e) {
// TODO: A MBean may have been unregistered.
// need to set up listener to listen for MBeanServerNotification.
} catch (ReflectionException e) {
// TODO: should log the error
}
return list;
}
/** Set the value of a specific attribute of a named MBean. */
public void setAttribute(ObjectName name, Attribute attribute)
throws InvalidAttributeValueException, MBeanException, IOException {
try {
server.setAttribute(name, attribute);
} catch (InstanceNotFoundException e) {
// TODO: A MBean may have been unregistered.
} catch (AttributeNotFoundException e) {
assert (false);
} catch (ReflectionException e) {
// TODO: should log the error
}
}
/**
* Invokes an operation of a named MBean.
*
* @throws MBeanException Wraps an exception thrown by the MBean's invoked method.
*/
public Object invoke(ObjectName name, String operationName, Object[] params, String[] signature)
throws IOException, MBeanException {
Object result = null;
try {
result = server.invoke(name, operationName, params, signature);
} catch (InstanceNotFoundException e) {
// TODO: A MBean may have been unregistered.
} catch (ReflectionException e) {
// TODO: should log the error
}
return result;
}
public synchronized ClassLoadingMXBean getClassLoadingMXBean() throws IOException {
if (hasPlatformMXBeans && classLoadingMBean == null) {
classLoadingMBean =
newPlatformMXBeanProxy(server, CLASS_LOADING_MXBEAN_NAME, ClassLoadingMXBean.class);
}
return classLoadingMBean;
}
public synchronized CompilationMXBean getCompilationMXBean() throws IOException {
if (hasCompilationMXBean && compilationMBean == null) {
compilationMBean =
newPlatformMXBeanProxy(server, COMPILATION_MXBEAN_NAME, CompilationMXBean.class);
}
return compilationMBean;
}
public Collection<MemoryPoolProxy> getMemoryPoolProxies() throws IOException {
// TODO: How to deal with changes to the list??
if (memoryPoolProxies == null) {
ObjectName poolName = null;
try {
poolName = new ObjectName(MEMORY_POOL_MXBEAN_DOMAIN_TYPE + ",*");
} catch (MalformedObjectNameException e) {
// should not reach here
assert (false);
}
Set<ObjectName> mbeans = server.queryNames(poolName, null);
if (mbeans != null) {
memoryPoolProxies = new ArrayList<MemoryPoolProxy>();
Iterator<ObjectName> iterator = mbeans.iterator();
while (iterator.hasNext()) {
ObjectName objName = (ObjectName) iterator.next();
MemoryPoolProxy p = new MemoryPoolProxy(this, objName);
memoryPoolProxies.add(p);
}
}
}
return memoryPoolProxies;
}
public synchronized Collection<GarbageCollectorMXBean> getGarbageCollectorMXBeans()
throws IOException {
// TODO: How to deal with changes to the list??
if (garbageCollectorMBeans == null) {
ObjectName gcName = null;
try {
gcName = new ObjectName(GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE + ",*");
} catch (MalformedObjectNameException e) {
// should not reach here
assert (false);
}
Set<ObjectName> mbeans = server.queryNames(gcName, null);
if (mbeans != null) {
garbageCollectorMBeans = new ArrayList<GarbageCollectorMXBean>();
Iterator<ObjectName> iterator = mbeans.iterator();
while (iterator.hasNext()) {
ObjectName on = (ObjectName) iterator.next();
String name = GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE + ",name=" + on.getKeyProperty("name");
GarbageCollectorMXBean mBean =
newPlatformMXBeanProxy(server, name, GarbageCollectorMXBean.class);
garbageCollectorMBeans.add(mBean);
}
}
}
return garbageCollectorMBeans;
}
public synchronized MemoryMXBean getMemoryMXBean() throws IOException {
if (hasPlatformMXBeans && memoryMBean == null) {
memoryMBean = newPlatformMXBeanProxy(server, MEMORY_MXBEAN_NAME, MemoryMXBean.class);
}
return memoryMBean;
}
public synchronized RuntimeMXBean getRuntimeMXBean() throws IOException {
if (hasPlatformMXBeans && runtimeMBean == null) {
runtimeMBean = newPlatformMXBeanProxy(server, RUNTIME_MXBEAN_NAME, RuntimeMXBean.class);
}
return runtimeMBean;
}
public synchronized ThreadMXBean getThreadMXBean() throws IOException {
if (hasPlatformMXBeans && threadMBean == null) {
threadMBean = newPlatformMXBeanProxy(server, THREAD_MXBEAN_NAME, ThreadMXBean.class);
}
return threadMBean;
}
public synchronized OperatingSystemMXBean getOperatingSystemMXBean() throws IOException {
if (hasPlatformMXBeans && operatingSystemMBean == null) {
operatingSystemMBean =
newPlatformMXBeanProxy(server, OPERATING_SYSTEM_MXBEAN_NAME, OperatingSystemMXBean.class);
}
return operatingSystemMBean;
}
public synchronized com.sun.management.OperatingSystemMXBean getSunOperatingSystemMXBean()
throws IOException {
try {
ObjectName on = new ObjectName(OPERATING_SYSTEM_MXBEAN_NAME);
if (sunOperatingSystemMXBean == null) {
if (server.isInstanceOf(on, "com.sun.management.OperatingSystemMXBean")) {
sunOperatingSystemMXBean =
newPlatformMXBeanProxy(
server,
OPERATING_SYSTEM_MXBEAN_NAME,
com.sun.management.OperatingSystemMXBean.class);
}
}
} catch (InstanceNotFoundException e) {
return null;
} catch (MalformedObjectNameException e) {
return null; // should never reach here
}
return sunOperatingSystemMXBean;
}
public synchronized HotSpotDiagnosticMXBean getHotSpotDiagnosticMXBean() throws IOException {
if (hasHotSpotDiagnosticMXBean && hotspotDiagnosticMXBean == null) {
hotspotDiagnosticMXBean =
newPlatformMXBeanProxy(
server, HOTSPOT_DIAGNOSTIC_MXBEAN_NAME, HotSpotDiagnosticMXBean.class);
}
return hotspotDiagnosticMXBean;
}
public <T> T getMXBean(ObjectName objName, Class<T> interfaceClass) throws IOException {
return newPlatformMXBeanProxy(server, objName.toString(), interfaceClass);
}
// Return thread IDs of deadlocked threads or null if any.
// It finds deadlocks involving only monitors if it's a Tiger VM.
// Otherwise, it finds deadlocks involving both monitors and
// the concurrent locks.
public long[] findDeadlockedThreads() throws IOException {
ThreadMXBean tm = getThreadMXBean();
if (supportsLockUsage && tm.isSynchronizerUsageSupported()) {
return tm.findDeadlockedThreads();
} else {
return tm.findMonitorDeadlockedThreads();
}
}
public synchronized void markAsDead() {
disconnect();
}
public boolean isDead() {
return isDead;
}
boolean isConnected() {
return !isDead();
}
boolean hasPlatformMXBeans() {
return this.hasPlatformMXBeans;
}
boolean hasHotSpotDiagnosticMXBean() {
return this.hasHotSpotDiagnosticMXBean;
}
boolean isLockUsageSupported() {
return supportsLockUsage;
}
public boolean isRegistered(ObjectName name) throws IOException {
return server.isRegistered(name);
}
public void addPropertyChangeListener(PropertyChangeListener listener) {
propertyChangeSupport.addPropertyChangeListener(listener);
}
public void addWeakPropertyChangeListener(PropertyChangeListener listener) {
if (!(listener instanceof WeakPCL)) {
listener = new WeakPCL(listener);
}
propertyChangeSupport.addPropertyChangeListener(listener);
}
public void removePropertyChangeListener(PropertyChangeListener listener) {
if (!(listener instanceof WeakPCL)) {
// Search for the WeakPCL holding this listener (if any)
for (PropertyChangeListener pcl : propertyChangeSupport.getPropertyChangeListeners()) {
if (pcl instanceof WeakPCL && ((WeakPCL) pcl).get() == listener) {
listener = pcl;
break;
}
}
}
propertyChangeSupport.removePropertyChangeListener(listener);
}
/**
* The PropertyChangeListener is handled via a WeakReference so as not to pin down the listener.
*/
private class WeakPCL extends WeakReference<PropertyChangeListener>
implements PropertyChangeListener {
WeakPCL(PropertyChangeListener referent) {
super(referent);
}
public void propertyChange(PropertyChangeEvent pce) {
PropertyChangeListener pcl = get();
if (pcl == null) {
// The referent listener was GC'ed, we're no longer
// interested in PropertyChanges, remove the listener.
dispose();
} else {
pcl.propertyChange(pce);
}
}
private void dispose() {
removePropertyChangeListener(this);
}
}
//
// Snapshot MBeanServerConnection:
//
// This is an object that wraps an existing MBeanServerConnection and adds
// caching to it, as follows:
//
// - The first time an attribute is called in a given MBean, the result is
// cached. Every subsequent time getAttribute is called for that attribute
// the cached result is returned.
//
// - Before every call to VMPanel.update() or when the Refresh button in the
// Attributes table is pressed down the attributes cache is flushed. Then
// any subsequent call to getAttribute will retrieve all the values for
// the attributes that are known to the cache.
//
// - The attributes cache uses a learning approach and only the attributes
// that are in the cache will be retrieved between two subsequent updates.
//
public interface SnapshotMBeanServerConnection extends MBeanServerConnection {
/** Flush all cached values of attributes. */
public void flush();
}
public static class Snapshot {
private Snapshot() {}
public static SnapshotMBeanServerConnection newSnapshot(MBeanServerConnection mbsc) {
final InvocationHandler ih = new SnapshotInvocationHandler(mbsc);
return (SnapshotMBeanServerConnection)
Proxy.newProxyInstance(
Snapshot.class.getClassLoader(),
new Class[] {SnapshotMBeanServerConnection.class},
ih);
}
}
static class SnapshotInvocationHandler implements InvocationHandler {
private final MBeanServerConnection conn;
private Map<ObjectName, NameValueMap> cachedValues = newMap();
private Map<ObjectName, Set<String>> cachedNames = newMap();
@SuppressWarnings("serial")
private static final class NameValueMap extends HashMap<String, Object> {}
SnapshotInvocationHandler(MBeanServerConnection conn) {
this.conn = conn;
}
synchronized void flush() {
cachedValues = newMap();
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
final String methodName = method.getName();
if (methodName.equals("getAttribute")) {
return getAttribute((ObjectName) args[0], (String) args[1]);
} else if (methodName.equals("getAttributes")) {
return getAttributes((ObjectName) args[0], (String[]) args[1]);
} else if (methodName.equals("flush")) {
flush();
return null;
} else {
try {
return method.invoke(conn, args);
} catch (InvocationTargetException e) {
throw e.getCause();
}
}
}
private Object getAttribute(ObjectName objName, String attrName)
throws MBeanException, InstanceNotFoundException, AttributeNotFoundException,
ReflectionException, IOException {
final NameValueMap values = getCachedAttributes(objName, Collections.singleton(attrName));
Object value = values.get(attrName);
if (value != null || values.containsKey(attrName)) {
return value;
}
// Not in cache, presumably because it was omitted from the
// getAttributes result because of an exception. Following
// call will probably provoke the same exception.
return conn.getAttribute(objName, attrName);
}
private AttributeList getAttributes(ObjectName objName, String[] attrNames)
throws InstanceNotFoundException, ReflectionException, IOException {
final NameValueMap values =
getCachedAttributes(objName, new TreeSet<String>(Arrays.asList(attrNames)));
final AttributeList list = new AttributeList();
for (String attrName : attrNames) {
final Object value = values.get(attrName);
if (value != null || values.containsKey(attrName)) {
list.add(new Attribute(attrName, value));
}
}
return list;
}
private synchronized NameValueMap getCachedAttributes(ObjectName objName, Set<String> attrNames)
throws InstanceNotFoundException, ReflectionException, IOException {
NameValueMap values = cachedValues.get(objName);
if (values != null && values.keySet().containsAll(attrNames)) {
return values;
}
attrNames = new TreeSet<String>(attrNames);
Set<String> oldNames = cachedNames.get(objName);
if (oldNames != null) {
attrNames.addAll(oldNames);
}
values = new NameValueMap();
final AttributeList attrs =
conn.getAttributes(objName, attrNames.toArray(new String[attrNames.size()]));
for (Attribute attr : attrs.asList()) {
values.put(attr.getName(), attr.getValue());
}
cachedValues.put(objName, values);
cachedNames.put(objName, attrNames);
return values;
}
// See http://www.artima.com/weblogs/viewpost.jsp?thread=79394
private static <K, V> Map<K, V> newMap() {
return new HashMap<K, V>();
}
}
}
