org.wildfly.security.manager.StackInspector Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* JBoss, Home of Professional Open Source.
* Copyright 2013 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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.wildfly.security.manager;
import static java.lang.Math.max;
import static java.lang.Math.min;
import static java.lang.System.getSecurityManager;
import static java.util.Arrays.copyOfRange;
import static org.wildfly.security.manager.WildFlySecurityManagerPermission.getStackInspectorPermission;
/**
* A utility class which is useful for inspecting the call stack.
*
* @author David M. Lloyd
*/
public final class StackInspector {
private static final StackInspector INSTANCE = new StackInspector();
private StackInspector() {
}
/**
* Get the singleton {@code StackInspector} instance. The caller must have the {@code getStackInspector}
* {@link RuntimePermission}.
* If the security manager is enabled, requires {@code getStackInspector} {@link WildFlySecurityManagerPermission}.
*
* @return the singleton {@code StackInspector} instance
*/
public static StackInspector getInstance() {
final SecurityManager securityManager = getSecurityManager();
if (securityManager instanceof WildFlySecurityManager) {
securityManager.checkPermission(getStackInspectorPermission, INSTANCE.getCallerClass(1));
} else if (securityManager != null) {
securityManager.checkPermission(getStackInspectorPermission);
}
return INSTANCE;
}
/**
* Get the caller class. The {@code skipFrames} argument specifies how many spots to go back
* on the call stack; 0 indicates the immediate caller.
*
* @param skipFrames the number of frames to skip over before the immediate caller
* @return the caller class
*/
public Class getCallerClass(int skipFrames) {
return WildFlySecurityManager.getCallerClass(max(0, skipFrames) + 1);
}
/**
* Get all or a portion of the call stack. The {@code numFrames} argument specifies how many frames should be
* returned.
*
* @param skipFrames the number of frames to skip; 0 will include the immediate caller at index 0
* @param numFrames the maximum number of frames to return
* @return the partial call stack
*/
public Class[] getCallStack(int skipFrames, int numFrames) {
final Class[] stack = WildFlySecurityManager.getCallStack();
final int from = max(0, skipFrames) + 2;
return copyOfRange(stack, from, min(from + numFrames, stack.length));
}
/**
* Get all or a portion of the call stack. The {@code numFrames} argument specifies how many frames should be
* returned.
*
* @param skipFrames the number of frames to skip; 0 will include the immediate caller at index 0
* @return the partial call stack
*/
public Class[] getCallStack(int skipFrames) {
final Class[] stack = WildFlySecurityManager.getCallStack();
final int from = max(0, skipFrames) + 2;
return copyOfRange(stack, from, stack.length);
}
/**
* Get the call stack.
*
* @return the call stack
*/
public Class[] getCallStack() {
final Class[] stack = WildFlySecurityManager.getCallStack();
return copyOfRange(stack, 2, stack.length);
}
/**
* Determine whether the call stack contains a given class. Useful for assertions.
*
* @param clazz the class to test
* @return {@code true} if the call stack contains the class
*/
public boolean callStackContains(Class clazz) {
final Class[] stack = WildFlySecurityManager.getCallStack();
for (int i = 2; i < stack.length; i ++) {
if (stack[i] == clazz) return true;
}
return false;
}
}