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Acessing MBean is something simple through the JMX API but it is often technical and not very interesting.
This example simplify this work simply doing it generically in a proxy.
So from an user side you simple declare an interface to access your MBeans.
Note: the example implementation uses a local MBeanServer but enhancing the example API it is easy to imagine a remote connection with user/password if needed.
Simply an annotation to get the object
package org.superbiz.dynamic.mbean;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
@Target({TYPE, METHOD})
@Retention(RUNTIME)
public @interface ObjectName {
String value();
// for remote usage only
String url() default "";
String user() default "";
String password() default "";
}
package org.superbiz.dynamic.mbean;
import javax.annotation.PreDestroy;
import javax.management.Attribute;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanInfo;
import javax.management.MBeanServer;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* Need a @PreDestroy method to disconnect the remote host when used in remote mode.
*/
public class DynamicMBeanHandler implements InvocationHandler {
private final Map<Method, ConnectionInfo> infos = new ConcurrentHashMap<Method, ConnectionInfo>();
@Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
final String methodName = method.getName();
if (method.getDeclaringClass().equals(Object.class) && "toString".equals(methodName)) {
return getClass().getSimpleName() + " Proxy";
}
if (method.getAnnotation(PreDestroy.class) != null) {
return destroy();
}
final ConnectionInfo info = getConnectionInfo(method);
final MBeanInfo infos = info.getMBeanInfo();
if (methodName.startsWith("set") && methodName.length() > 3 && args != null && args.length == 1
&& (Void.TYPE.equals(method.getReturnType()) || Void.class.equals(method.getReturnType()))) {
final String attributeName = attributeName(infos, methodName, method.getParameterTypes()[0]);
info.setAttribute(new Attribute(attributeName, args[0]));
return null;
} else if (methodName.startsWith("get") && (args == null || args.length == 0) && methodName.length() > 3) {
final String attributeName = attributeName(infos, methodName, method.getReturnType());
return info.getAttribute(attributeName);
}
// operation
return info.invoke(methodName, args, getSignature(method));
}
public Object destroy() {
for (ConnectionInfo info : infos.values()) {
info.clean();
}
infos.clear();
return null;
}
private String[] getSignature(Method method) {
String[] args = new String[method.getParameterTypes().length];
for (int i = 0; i < method.getParameterTypes().length; i++) {
args[i] = method.getParameterTypes()[i].getName();
}
return args; // note: null should often work...
}
private String attributeName(MBeanInfo infos, String methodName, Class<?> type) {
String found = null;
String foundBackUp = null; // without checking the type
final String attributeName = methodName.substring(3, methodName.length());
final String lowerName = Character.toLowerCase(methodName.charAt(3)) + methodName.substring(4, methodName.length());
for (MBeanAttributeInfo attribute : infos.getAttributes()) {
final String name = attribute.getName();
if (attributeName.equals(name)) {
foundBackUp = attributeName;
if (attribute.getType().equals(type.getName())) {
found = name;
}
} else if (found == null && ((lowerName.equals(name) && !attributeName.equals(name))
|| lowerName.equalsIgnoreCase(name))) {
foundBackUp = name;
if (attribute.getType().equals(type.getName())) {
found = name;
}
}
}
if (found == null && foundBackUp == null) {
throw new UnsupportedOperationException("cannot find attribute " + attributeName);
}
if (found != null) {
return found;
}
return foundBackUp;
}
private synchronized ConnectionInfo getConnectionInfo(Method method) throws Exception {
if (!infos.containsKey(method)) {
synchronized (infos) {
if (!infos.containsKey(method)) { // double check for synchro
org.superbiz.dynamic.mbean.ObjectName on = method.getAnnotation(org.superbiz.dynamic.mbean.ObjectName.class);
if (on == null) {
Class<?> current = method.getDeclaringClass();
do {
on = method.getDeclaringClass().getAnnotation(org.superbiz.dynamic.mbean.ObjectName.class);
current = current.getSuperclass();
} while (on == null && current != null);
if (on == null) {
throw new UnsupportedOperationException("class or method should define the objectName to use for invocation: " + method.toGenericString());
}
}
final ConnectionInfo info;
if (on.url().isEmpty()) {
info = new LocalConnectionInfo();
((LocalConnectionInfo) info).server = ManagementFactory.getPlatformMBeanServer(); // could use an id...
} else {
info = new RemoteConnectionInfo();
final Map<String, String[]> environment = new HashMap<String, String[]>();
if (!on.user().isEmpty()) {
environment.put(JMXConnector.CREDENTIALS, new String[]{ on.user(), on.password() });
}
// ((RemoteConnectionInfo) info).connector = JMXConnectorFactory.newJMXConnector(new JMXServiceURL(on.url()), environment);
((RemoteConnectionInfo) info).connector = JMXConnectorFactory.connect(new JMXServiceURL(on.url()), environment);
}
info.objectName = new ObjectName(on.value());
infos.put(method, info);
}
}
}
return infos.get(method);
}
private abstract static class ConnectionInfo {
protected ObjectName objectName;
public abstract void setAttribute(Attribute attribute) throws Exception;
public abstract Object getAttribute(String attribute) throws Exception;
public abstract Object invoke(String operationName, Object params[], String signature[]) throws Exception;
public abstract MBeanInfo getMBeanInfo() throws Exception;
public abstract void clean();
}
private static class LocalConnectionInfo extends ConnectionInfo {
private MBeanServer server;
@Override public void setAttribute(Attribute attribute) throws Exception {
server.setAttribute(objectName, attribute);
}
@Override public Object getAttribute(String attribute) throws Exception {
return server.getAttribute(objectName, attribute);
}
@Override
public Object invoke(String operationName, Object[] params, String[] signature) throws Exception {
return server.invoke(objectName, operationName, params, signature);
}
@Override public MBeanInfo getMBeanInfo() throws Exception {
return server.getMBeanInfo(objectName);
}
@Override public void clean() {
// no-op
}
}
private static class RemoteConnectionInfo extends ConnectionInfo {
private JMXConnector connector;
private MBeanServerConnection connection;
private void before() throws IOException {
connection = connector.getMBeanServerConnection();
}
private void after() throws IOException {
// no-op
}
@Override public void setAttribute(Attribute attribute) throws Exception {
before();
connection.setAttribute(objectName, attribute);
after();
}
@Override public Object getAttribute(String attribute) throws Exception {
before();
try {
return connection.getAttribute(objectName, attribute);
} finally {
after();
}
}
@Override
public Object invoke(String operationName, Object[] params, String[] signature) throws Exception {
before();
try {
return connection.invoke(objectName, operationName, params, signature);
} finally {
after();
}
}
@Override public MBeanInfo getMBeanInfo() throws Exception {
before();
try {
return connection.getMBeanInfo(objectName);
} finally {
after();
}
}
@Override public void clean() {
try {
connector.close();
} catch (IOException e) {
// no-op
}
}
}
}
package org.superbiz.dynamic.mbean;
import org.apache.openejb.api.Proxy;
import org.superbiz.dynamic.mbean.DynamicMBeanHandler;
import org.superbiz.dynamic.mbean.ObjectName;
import javax.ejb.Singleton;
/**
* @author rmannibucau
*/
@Singleton
@Proxy(DynamicMBeanHandler.class)
@ObjectName(DynamicMBeanClient.OBJECT_NAME)
public interface DynamicMBeanClient {
static final String OBJECT_NAME = "test:group=DynamicMBeanClientTest";
int getCounter();
void setCounter(int i);
int length(String aString);
}
package org.superbiz.dynamic.mbean;
import org.apache.openejb.api.Proxy;
import javax.annotation.PreDestroy;
import javax.ejb.Singleton;
@Singleton
@Proxy(DynamicMBeanHandler.class)
@ObjectName(value = DynamicRemoteMBeanClient.OBJECT_NAME, url = "service:jmx:rmi:///jndi/rmi://localhost:8243/jmxrmi")
public interface DynamicRemoteMBeanClient {
static final String OBJECT_NAME = "test:group=DynamicMBeanClientTest";
int getCounter();
void setCounter(int i);
int length(String aString);
@PreDestroy void clean();
}
package org.superbiz.dynamic.mbean.simple;
public interface SimpleMBean {
int length(String s);
int getCounter();
void setCounter(int c);
}
package org.superbiz.dynamic.mbean.simple;
public class Simple implements SimpleMBean {
private int counter = 0;
@Override public int length(String s) {
if (s == null) {
return 0;
}
return s.length();
}
@Override public int getCounter() {
return counter;
}
@Override public void setCounter(int c) {
counter = c;
}
}
package org.superbiz.dynamic.mbean;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.superbiz.dynamic.mbean.simple.Simple;
import javax.ejb.EJB;
import javax.ejb.embeddable.EJBContainer;
import javax.management.Attribute;
import javax.management.ObjectName;
import java.lang.management.ManagementFactory;
import static junit.framework.Assert.assertEquals;
public class DynamicMBeanClientTest {
private static ObjectName objectName;
private static EJBContainer container;
@EJB private DynamicMBeanClient localClient;
@EJB private DynamicRemoteMBeanClient remoteClient;
@BeforeClass public static void start() {
container = EJBContainer.createEJBContainer();
}
@Before public void injectAndRegisterMBean() throws Exception {
container.getContext().bind("inject", this);
objectName = new ObjectName(DynamicMBeanClient.OBJECT_NAME);
ManagementFactory.getPlatformMBeanServer().registerMBean(new Simple(), objectName);
}
@After public void unregisterMBean() throws Exception {
if (objectName != null) {
ManagementFactory.getPlatformMBeanServer().unregisterMBean(objectName);
}
}
@Test public void localGet() throws Exception {
assertEquals(0, localClient.getCounter());
ManagementFactory.getPlatformMBeanServer().setAttribute(objectName, new Attribute("Counter", 5));
assertEquals(5, localClient.getCounter());
}
@Test public void localSet() throws Exception {
assertEquals(0, ((Integer) ManagementFactory.getPlatformMBeanServer().getAttribute(objectName, "Counter")).intValue());
localClient.setCounter(8);
assertEquals(8, ((Integer) ManagementFactory.getPlatformMBeanServer().getAttribute(objectName, "Counter")).intValue());
}
@Test public void localOperation() {
assertEquals(7, localClient.length("openejb"));
}
@Test public void remoteGet() throws Exception {
assertEquals(0, remoteClient.getCounter());
ManagementFactory.getPlatformMBeanServer().setAttribute(objectName, new Attribute("Counter", 5));
assertEquals(5, remoteClient.getCounter());
}
@Test public void remoteSet() throws Exception {
assertEquals(0, ((Integer) ManagementFactory.getPlatformMBeanServer().getAttribute(objectName, "Counter")).intValue());
remoteClient.setCounter(8);
assertEquals(8, ((Integer) ManagementFactory.getPlatformMBeanServer().getAttribute(objectName, "Counter")).intValue());
}
@Test public void remoteOperation() {
assertEquals(7, remoteClient.length("openejb"));
}
@AfterClass public static void close() {
if (container != null) {
container.close();
}
}
}
svn co http://svn.apache.org/repos/asf/tomee/tomee/trunk/examples/dynamic-proxy-to-access-mbean cd dynamic-proxy-to-access-mbean mvn clean install