com.gemstone.gemfire.management.internal.cli.util.spring.ReflectionUtils Maven / Gradle / Ivy
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/*
* Copyright 2011-2012 the original author or authors.
*
* 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 com.gemstone.gemfire.management.internal.cli.util.spring;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* Replaces org.springframework.shell.support.util.ReflectionUtils which
* is now removed from SPring Shell & the same class is referred from Spring
* Core. With this we can avoid GemFire member's runtime dependency on Spring
* Core.
*/
/*
* Code selectively taken from the original org.springframework.shell.support.util.ReflectionUtils
*/
public class ReflectionUtils {
/**
* Invoke the specified {@link Method} against the supplied target object
* with the supplied arguments. The target object can be null
* when invoking a static {@link Method}.
* Thrown exceptions are handled via a call to {@link #handleReflectionException}.
* @param method the method to invoke
* @param target the target object to invoke the method on
* @param args the invocation arguments (may be null)
* @return the invocation result, if any
*/
public static Object invokeMethod(final Method method, final Object target, final Object[] args) {
try {
return method.invoke(target, args);
}
catch (Exception ex) {
handleReflectionException(ex);
}
throw new IllegalStateException("Should never get here");
}
/**
* Handle the given reflection exception. Should only be called if
* no checked exception is expected to be thrown by the target method.
*
Throws the underlying RuntimeException or Error in case of an
* InvocationTargetException with such a root cause. Throws an
* IllegalStateException with an appropriate message else.
* @param ex the reflection exception to handle
*/
public static void handleReflectionException(final Exception ex) {
if (ex instanceof NoSuchMethodException) {
throw new IllegalStateException("Method not found: " + ex.getMessage());
}
if (ex instanceof IllegalAccessException) {
throw new IllegalStateException("Could not access method: " + ex.getMessage());
}
if (ex instanceof InvocationTargetException) {
handleInvocationTargetException((InvocationTargetException) ex);
}
if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
}
handleUnexpectedException(ex);
}
/**
* Handle the given invocation target exception. Should only be called if
* no checked exception is expected to be thrown by the target method.
*
Throws the underlying RuntimeException or Error in case of such
* a root cause. Throws an IllegalStateException else.
* @param ex the invocation target exception to handle
*/
public static void handleInvocationTargetException(final InvocationTargetException ex) {
rethrowRuntimeException(ex.getTargetException());
}
/**
* Rethrow the given {@link Throwable exception}, which is presumably the
* target exception of an {@link InvocationTargetException}.
* Should only be called if no checked exception is expected to be thrown by
* the target method.
*
Rethrows the underlying exception cast to an {@link RuntimeException}
* or {@link Error} if appropriate; otherwise, throws an
* {@link IllegalStateException}.
* @param ex the exception to rethrow
* @throws RuntimeException the rethrown exception
*/
public static void rethrowRuntimeException(final Throwable ex) {
if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
}
if (ex instanceof Error) {
throw (Error) ex;
}
handleUnexpectedException(ex);
}
/**
* Throws an IllegalStateException with the given exception as root cause.
* @param ex the unexpected exception
*/
private static void handleUnexpectedException(final Throwable ex) {
throw new IllegalStateException("Unexpected exception thrown", ex);
}
}