/*
* Copyright (c) 2008-2017 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 org.cometd.annotation;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Inject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Base class for common functionality in annotation processors
*/
class AnnotationProcessor {
protected final Logger logger = LoggerFactory.getLogger(getClass().getName());
protected boolean processPostConstruct(Object bean) {
if (bean == null) {
return false;
}
List<Method> postConstructs = findLifeCycleMethods(bean, PostConstruct.class);
boolean result = false;
for (Method method : postConstructs) {
invokePrivate(bean, method);
result = true;
}
return result;
}
protected boolean processPreDestroy(Object bean) {
if (bean == null) {
return false;
}
List<Method> preDestroys = findLifeCycleMethods(bean, PreDestroy.class);
boolean result = false;
for (Method method : preDestroys) {
try {
invokePrivate(bean, method);
result = true;
} catch (RuntimeException x) {
if (logger.isDebugEnabled()) {
logger.debug("Exception while invoking @PreDestroy method " + method + ", ignoring", x);
}
}
}
return result;
}
private List<Method> findLifeCycleMethods(Object bean, Class<? extends Annotation> lifeCycle) {
List<Class<?>> classes = new ArrayList<>();
for (Class<?> c = bean.getClass(); c != Object.class; c = c.getSuperclass()) {
classes.add(c);
}
Collections.reverse(classes);
List<Method> result = new ArrayList<>();
for (int i = 0; i < classes.size(); ++i) {
Class<?> c = classes.get(i);
boolean foundInClass = false;
Method[] methods = c.getDeclaredMethods();
for (Method method : methods) {
Annotation annotation = method.getAnnotation(lifeCycle);
if (annotation != null) {
if (foundInClass) {
throw new RuntimeException("Invalid @" + lifeCycle.getSimpleName() + " method " + method + ": another method with the same annotation exists");
}
foundInClass = true;
if (method.getReturnType() != Void.TYPE) {
throw new RuntimeException("Invalid @" + lifeCycle.getSimpleName() + " method " + method + ": it must have void return type");
}
if (method.getParameterTypes().length > 0) {
throw new RuntimeException("Invalid @" + lifeCycle.getSimpleName() + " method " + method + ": it must have no parameters");
}
if (Modifier.isStatic(method.getModifiers())) {
throw new RuntimeException("Invalid @" + lifeCycle.getSimpleName() + " method " + method + ": it must not be static");
}
// Check if the method has not been overridden.
boolean overridden = false;
for (int j = i + 1; j < classes.size(); ++j) {
try {
Class<?> sc = classes.get(j);
sc.getDeclaredMethod(method.getName(), method.getParameterTypes());
overridden = true;
break;
} catch (Exception ignored) {
}
}
if (!overridden) {
result.add(method);
}
}
}
}
Collections.reverse(result);
return result;
}
protected List<Method> findAnnotatedMethods(Object bean, Class<? extends Annotation> annotationClass) {
List<Class<?>> classes = new ArrayList<>();
for (Class<?> c = bean.getClass(); c != Object.class; c = c.getSuperclass()) {
classes.add(c);
}
Collections.reverse(classes);
List<Method> result = new ArrayList<>();
for (int i = 0; i < classes.size(); ++i) {
Class<?> c = classes.get(i);
Method[] methods = c.getDeclaredMethods();
for (Method method : methods) {
Annotation annotation = method.getAnnotation(annotationClass);
if (annotation != null) {
// Check if the method has not been overridden.
boolean overridden = false;
for (int j = i + 1; j < classes.size(); ++j) {
try {
Class<?> sc = classes.get(j);
sc.getDeclaredMethod(method.getName(), method.getParameterTypes());
overridden = true;
break;
} catch (Exception ignored) {
}
}
if (!overridden) {
result.add(method);
}
}
}
}
Collections.reverse(result);
return result;
}
protected List<String> processParameters(Method method) {
List<String> result = new ArrayList<>();
Annotation[][] parametersAnnotations = method.getParameterAnnotations();
for (Annotation[] parameterAnnotations : parametersAnnotations) {
for (Annotation parameterAnnotation : parameterAnnotations) {
if (parameterAnnotation instanceof Param) {
result.add(((Param)parameterAnnotation).value());
}
}
}
return result;
}
protected Object invokePrivate(Object bean, Method method, Object... args) {
boolean accessible = method.isAccessible();
try {
method.setAccessible(true);
return method.invoke(bean, args);
} catch (InvocationTargetException x) {
throw new RuntimeException(x.getCause());
} catch (Exception x) {
throw new RuntimeException(x);
} finally {
method.setAccessible(accessible);
}
}
protected static Object invokePublic(Object target, Method method, Object... arguments) {
try {
return method.invoke(target, arguments);
} catch (InvocationTargetException x) {
Throwable cause = x.getCause();
if (cause instanceof RuntimeException) {
throw (RuntimeException)cause;
}
if (cause instanceof Error) {
throw (Error)cause;
}
throw new RuntimeException(cause);
} catch (IllegalAccessException x) {
throw new RuntimeException(x);
}
}
protected Object getField(Object bean, Field field) {
boolean accessible = field.isAccessible();
try {
field.setAccessible(true);
return field.get(bean);
} catch (IllegalAccessException x) {
throw new RuntimeException(x);
} finally {
field.setAccessible(accessible);
}
}
protected void setField(Object bean, Field field, Object value) {
boolean accessible = field.isAccessible();
try {
field.setAccessible(true);
field.set(bean, value);
} catch (IllegalAccessException x) {
throw new RuntimeException(x);
} finally {
field.setAccessible(accessible);
}
}
protected static void checkMethodsPublic(Object bean, Class<? extends Annotation> annotationClass) {
for (Class<?> c = bean.getClass(); c != Object.class; c = c.getSuperclass()) {
Method[] methods = c.getDeclaredMethods();
for (Method method : methods) {
Annotation annotation = method.getAnnotation(annotationClass);
if (annotation != null) {
if (!Modifier.isPublic(method.getModifiers())) {
throw new IllegalArgumentException("@" + annotationClass.getSimpleName() + " method " +
method.getDeclaringClass().getName() + "." + method.getName() + "(...) must be public");
}
}
}
}
}
protected static void checkSignaturesMatch(Method method, Class<?>[] expectedTypes, List<String> paramNames) {
Class<?>[] paramTypes = method.getParameterTypes();
if (paramTypes.length != expectedTypes.length + paramNames.size()) {
throw new IllegalArgumentException("Wrong number of parameters in service method: " + method.getName() + "(...)." +
(paramTypes.length > 2 ? " Template parameters not annotated with @" + Param.class.getSimpleName() + " ?" : ""));
}
for (int i = 0; i < expectedTypes.length; ++i) {
Class<?> expected = expectedTypes[i];
if (expected == null) {
continue;
}
Class<?> parameter = paramTypes[i];
if (!parameter.isAssignableFrom(expected)) {
throw new IllegalArgumentException("Parameter type " + parameter.getName() + " must be instead " +
expected.getName() + " in service method: " + method.getName() + "(...).");
}
}
for (int i = 0; i < paramNames.size(); ++i) {
Class<?> parameter = paramTypes[expectedTypes.length + i];
if (!parameter.isAssignableFrom(String.class)) {
throw new IllegalArgumentException("Template parameter '" + paramNames.get(i) + "' must be of type " +
String.class.getName() + " in service method: " + method.getName() + "(...).");
}
}
}
protected boolean processInjectables(Object bean, List<Object> injectables) {
boolean result = false;
for (Object injectable : injectables) {
result |= processInjectable(bean, injectable);
}
return result;
}
protected boolean processInjectable(Object bean, Object injectable) {
boolean result = false;
for (Class<?> c = bean.getClass(); c != Object.class; c = c.getSuperclass()) {
Field[] fields = c.getDeclaredFields();
for (Field field : fields) {
if (field.getAnnotation(Inject.class) != null) {
if (field.getType().isAssignableFrom(injectable.getClass())) {
Object value = getField(bean, field);
if (value != null) {
if (logger.isDebugEnabled()) {
logger.debug("Avoid injection of field {} on bean {}, it's already injected with {}", field, bean, value);
}
continue;
}
setField(bean, field, injectable);
result = true;
if (logger.isDebugEnabled()) {
logger.debug("Injected {} to field {} on bean {}", injectable, field, bean);
}
}
}
}
}
List<Method> methods = findAnnotatedMethods(bean, Inject.class);
for (Method method : methods) {
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length == 1) {
if (parameterTypes[0].isAssignableFrom(injectable.getClass())) {
invokePrivate(bean, method, injectable);
result = true;
if (logger.isDebugEnabled()) {
logger.debug("Injected {} to method {} on bean {}", injectable, method, bean);
}
}
}
}
return result;
}
}