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/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2019-2021 Payara Foundation and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://github.com/payara/Payara/blob/master/LICENSE.txt
* See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* The Payara Foundation designates this particular file as subject to the "Classpath"
* exception as provided by the Payara Foundation in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
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package fish.payara.microprofile.faulttolerance.policy;
import java.lang.reflect.Method;
import java.util.Objects;
import jakarta.interceptor.InvocationContext;
import org.eclipse.microprofile.faulttolerance.ExecutionContext;
import org.eclipse.microprofile.faulttolerance.Fallback;
import org.eclipse.microprofile.faulttolerance.FallbackHandler;
import org.eclipse.microprofile.faulttolerance.exceptions.FaultToleranceDefinitionException;
import fish.payara.microprofile.faulttolerance.FaultToleranceConfig;
import javassist.Modifier;
/**
* The resolved "cached" information of a {@link Fallback} annotation an a specific method.
*
* @author Jan Bernitt
*/
public final class FallbackPolicy extends Policy {
public final Class> value;
public final String fallbackMethod;
public final Method method;
private final Class[] applyOn;
private final Class[] skipOn;
@SuppressWarnings("unchecked")
public FallbackPolicy(Method annotated, Class> value, String fallbackMethod) {
this(annotated, value, fallbackMethod, new Class[] { Throwable.class }, new Class[0]);
}
public FallbackPolicy(Method annotated, Class> value, String fallbackMethod,
Class[] applyOn, Class[] skipOn) {
checkUnambiguous(annotated, value, fallbackMethod);
this.value = value;
this.fallbackMethod = fallbackMethod;
if (fallbackMethod != null && !fallbackMethod.isEmpty()) {
method = MethodLookupUtils.findMethodWithMatchingNameAndArguments(fallbackMethod, annotated);
if (method == null) {
throw new FaultToleranceDefinitionException(describe(annotated, Fallback.class, "fallbackMethod")
+ "value referring to a method that is not defined or has a incompatible method signature.");
}
checkReturnsSameAs(annotated, Fallback.class, "fallbackMethod", method);
checkAccessible(annotated, method);
} else {
method = null;
}
if (isHandlerPresent()) {
checkReturnsSameAs(annotated, Fallback.class, "value", value, "handle", ExecutionContext.class);
}
this.applyOn = applyOn;
this.skipOn = skipOn;
}
public static FallbackPolicy create(InvocationContext context, FaultToleranceConfig config) {
if (config.isAnnotationPresent(Fallback.class) && config.isEnabled(Fallback.class)) {
Fallback annotation = config.getAnnotation(Fallback.class);
return new FallbackPolicy(context.getMethod(),
config.value(annotation),
config.fallbackMethod(annotation),
config.applyOn(annotation),
config.skipOn(annotation));
}
return null;
}
private static void checkUnambiguous(Method annotated, Class> value, String fallbackMethod) {
if (fallbackMethod != null && !fallbackMethod.isEmpty() && value != null && value != Fallback.DEFAULT.class) {
throw new FaultToleranceDefinitionException(
describe(annotated, Fallback.class, "") + "defined both a fallback handler and a fallback method.");
}
}
private static void checkAccessible(Method annotated, Method fallback) {
boolean samePackage = Objects.equals(
fallback.getDeclaringClass().getPackage(),
annotated.getDeclaringClass().getPackage()
);
boolean sameClass = fallback.getDeclaringClass().equals(annotated.getDeclaringClass());
if (Modifier.isPackage(fallback.getModifiers()) && !samePackage
|| Modifier.isPrivate(fallback.getModifiers()) && !sameClass) {
throw new FaultToleranceDefinitionException(describe(annotated, Fallback.class, "fallbackMethod")
+ "value referring to a method that is not accessible.");
}
}
public boolean isHandlerPresent() {
return value != null && value != Fallback.DEFAULT.class;
}
/**
* Helper method that checks whether or not the given exception is should trigger applying the fallback or not.
*
* Relevant section from {@link Fallback} javadocs:
*
* When a method returns and the Fallback policy is present, the following rules are applied:
*
* - If the method returns normally (doesn't throw), the result is simply returned.
*
- Otherwise, if the thrown object is assignable to any value in the {@link #skipOn()} parameter, the thrown object will be rethrown.
*
- Otherwise, if the thrown object is assignable to any value in the {@link #applyOn()} parameter,
* the Fallback policy, detailed above, will be applied.
*
- Otherwise the thrown object will be rethrown.
*
*
*
* @param ex The exception to check
* @return true, when fallback should be applied, false to rethrow the exception
*/
public boolean isFallbackApplied(Throwable ex) {
return !Policy.isCaught(ex, skipOn) && Policy.isCaught(ex, applyOn);
}
}