/*
* @(#)PerInterface.java 1.5 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package com.sun.jmx.mbeanserver;
import java.security.AccessController;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import javax.management.AttributeNotFoundException;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.ReflectionException;
import static com.sun.jmx.mbeanserver.Util.*;
/**
* Per-MBean-interface behavior. A single instance of this class can be shared
* by all MBeans of the same kind (Standard MBean or MXBean) that have the same
* MBean interface.
*
* @since 1.6
*/
final class PerInterface<M> {
PerInterface(Class<?> mbeanInterface, MBeanIntrospector<M> introspector,
MBeanAnalyzer<M> analyzer, MBeanInfo mbeanInfo) {
this.mbeanInterface = mbeanInterface;
this.introspector = introspector;
this.mbeanInfo = mbeanInfo;
analyzer.visit(new InitMaps());
}
Class<?> getMBeanInterface() {
return mbeanInterface;
}
MBeanInfo getMBeanInfo() {
return mbeanInfo;
}
boolean isMXBean() {
return introspector.isMXBean();
}
Object getAttribute(Object resource, String attribute, Object cookie)
throws AttributeNotFoundException,
MBeanException,
ReflectionException {
final M cm = getters.get(attribute);
if (cm == null) {
final String msg;
if (setters.containsKey(attribute))
msg = "Write-only attribute: " + attribute;
else
msg = "No such attribute: " + attribute;
throw new AttributeNotFoundException(msg);
}
return introspector.invokeM(cm, resource, (Object[]) null, cookie);
}
void setAttribute(Object resource, String attribute, Object value,
Object cookie)
throws AttributeNotFoundException,
InvalidAttributeValueException,
MBeanException,
ReflectionException {
final M cm = setters.get(attribute);
if (cm == null) {
final String msg;
if (getters.containsKey(attribute))
msg = "Read-only attribute: " + attribute;
else
msg = "No such attribute: " + attribute;
throw new AttributeNotFoundException(msg);
}
introspector.invokeSetter(attribute, cm, resource, value, cookie);
}
Object invoke(Object resource, String operation, Object[] params,
String[] signature, Object cookie)
throws MBeanException, ReflectionException {
final List<MethodAndSig> list = ops.get(operation);
if (list == null) {
final String msg = "No such operation: " + operation;
return noSuchMethod(msg, resource, operation, params, signature,
cookie);
}
if (signature == null)
signature = new String[0];
MethodAndSig found = null;
for (MethodAndSig mas : list) {
if (Arrays.equals(mas.signature, signature)) {
found = mas;
break;
}
}
if (found == null) {
final String badSig = sigString(signature);
final String msg;
if (list.size() == 1) { // helpful exception message
msg = "Signature mismatch for operation " + operation +
": " + badSig + " should be " +
sigString(list.get(0).signature);
} else {
msg = "Operation " + operation + " exists but not with " +
"this signature: " + badSig;
}
return noSuchMethod(msg, resource, operation, params, signature,
cookie);
}
return introspector.invokeM(found.method, resource, params, cookie);
}
/*
* This method is called when invoke doesn't find the named method.
* Before throwing an exception, we check to see whether the
* jmx.invoke.getters property is set, and if so whether the method
* being invoked might be a getter or a setter. If so we invoke it
* and return the result. This is for compatibility
* with code based on JMX RI 1.0 or 1.1 which allowed invoking getters
* and setters. It is *not* recommended that new code use this feature.
*
* Since this method is either going to throw an exception or use
* functionality that is strongly discouraged, we consider that its
* performance is not very important.
*
* A simpler way to implement the functionality would be to add the getters
* and setters to the operations map when jmx.invoke.getters is set.
* However, that means that the property is consulted when an MBean
* interface is being introspected and not thereafter. Previously,
* the property was consulted on every invocation. So this simpler
* implementation could potentially break code that sets and unsets
* the property at different times.
*/
private Object noSuchMethod(String msg, Object resource, String operation,
Object[] params, String[] signature,
Object cookie)
throws MBeanException, ReflectionException {
// Construct the exception that we will probably throw
final NoSuchMethodException nsme =
new NoSuchMethodException(operation + sigString(signature));
final ReflectionException exception =
new ReflectionException(nsme, msg);
if (introspector.isMXBean())
throw exception; // No compatibility requirement here
// Is the compatibility property set?
GetPropertyAction act = new GetPropertyAction("jmx.invoke.getters");
String invokeGettersS;
try {
invokeGettersS = AccessController.doPrivileged(act);
} catch (Exception e) {
// We don't expect an exception here but if we get one then
// we'll simply assume that the property is not set.
invokeGettersS = null;
}
if (invokeGettersS == null)
throw exception;
int rest = 0;
Map<String, M> methods = null;
if (signature == null || signature.length == 0) {
if (operation.startsWith("get"))
rest = 3;
else if (operation.startsWith("is"))
rest = 2;
if (rest != 0)
methods = getters;
} else if (signature != null && signature.length == 1 &&
operation.startsWith("set")) {
rest = 3;
methods = setters;
}
if (rest != 0) {
String attrName = operation.substring(rest);
M method = methods.get(attrName);
if (method != null && introspector.getName(method).equals(operation)) {
String[] msig = introspector.getSignature(method);
if ((signature == null && msig.length == 0) ||
Arrays.equals(signature, msig)) {
return introspector.invokeM(method, resource, params, cookie);
}
}
}
throw exception;
}
private String sigString(String[] signature) {
StringBuilder b = new StringBuilder("(");
if (signature != null) {
for (String s : signature) {
if (b.length() > 1)
b.append(", ");
b.append(s);
}
}
return b.append(")").toString();
}
/**
* Visitor that sets up the method maps (operations, getters, setters).
*/
private class InitMaps implements MBeanAnalyzer.MBeanVisitor<M> {
public void visitAttribute(String attributeName,
M getter,
M setter) {
if (getter != null) {
introspector.checkMethod(getter);
final Object old = getters.put(attributeName, getter);
assert(old == null);
}
if (setter != null) {
introspector.checkMethod(setter);
final Object old = setters.put(attributeName, setter);
assert(old == null);
}
}
public void visitOperation(String operationName,
M operation) {
introspector.checkMethod(operation);
final String[] sig = introspector.getSignature(operation);
final MethodAndSig mas = new MethodAndSig();
mas.method = operation;
mas.signature = sig;
List<MethodAndSig> list = ops.get(operationName);
if (list == null)
list = Collections.singletonList(mas);
else {
if (list.size() == 1)
list = newList(list);
list.add(mas);
}
ops.put(operationName, list);
}
}
private class MethodAndSig {
M method;
String[] signature;
}
private final Class<?> mbeanInterface;
private final MBeanIntrospector<M> introspector;
private final MBeanInfo mbeanInfo;
private final Map<String, M> getters = newMap();
private final Map<String, M> setters = newMap();
private final Map<String, List<MethodAndSig>> ops = newMap();
}
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