ro.pippo.controller.util.ClassUtils Maven / Gradle / Ivy
/*
* Copyright (C) 2016 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 ro.pippo.controller.util;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import ro.pippo.core.PippoRuntimeException;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.Objects;
import java.util.function.Supplier;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;
import java.util.stream.Collectors;
/**
* Class reflection utility methods.
*
* @author James Moger
*/
public class ClassUtils {
private final static Logger log = LoggerFactory.getLogger(ClassUtils.class);
@SuppressWarnings("unchecked")
public static Class getClass(String className) {
try {
return (Class) Class.forName(className);
} catch (Exception e) {
throw new PippoRuntimeException("Failed to get class '{}'", className);
}
}
/**
* Returns the list of all classes within a package.
*
* @param packageNames
* @return a collection of classes
*/
public static Collection> getClasses(String... packageNames) {
List> classes = new ArrayList<>();
for (String packageName : packageNames) {
final String packagePath = packageName.replace('.', '/');
final String packagePrefix = packageName + '.';
List packageUrls = getResources(packagePath);
for (URL packageUrl : packageUrls) {
if (packageUrl.getProtocol().equals("jar")) {
log.debug("Scanning jar {} for classes", packageUrl);
try {
String jar = packageUrl.toString().substring("jar:".length()).split("!")[0];
File file = new File(new URI(jar));
try (JarInputStream is = new JarInputStream(new FileInputStream(file))) {
JarEntry entry;
while ((entry = is.getNextJarEntry()) != null) {
if (!entry.isDirectory() && entry.getName().endsWith(".class")) {
String className = entry.getName().replace(".class", "").replace('/', '.');
if (className.startsWith(packagePrefix)) {
Class aClass = getClass(className);
classes.add(aClass);
}
}
}
}
} catch (URISyntaxException | IOException e) {
throw new PippoRuntimeException("Failed to get classes for package '{}'", e, packageName);
}
} else {
log.debug("Scanning filesystem {} for classes", packageUrl);
log.debug(packageUrl.getProtocol());
try (InputStream is = packageUrl.openStream()) {
Objects.requireNonNull(is, String.format("Package url %s stream is null!", packageUrl));
try (BufferedReader reader = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8))) {
classes.addAll(reader.lines()
.filter(line -> line != null && line.endsWith(".class"))
.map(line -> {
String className = line.replace(".class", "").replace('/', '.');
try {
return getClass(packagePrefix + className);
} catch (Exception e) {
log.error("Failed to find {}", line, e);
}
return null;
})
.collect(Collectors.toList()));
}
} catch (IOException e) {
throw new PippoRuntimeException("Failed to get classes for package '{}'", e, packageName);
}
}
}
}
return Collections.unmodifiableCollection(classes);
}
/**
* Gets all sub types in hierarchy of a given type.
*/
public static Collection> getSubTypesOf(Class type, String... packageNames) {
List> classes = getClasses(packageNames).stream()
.filter(aClass -> type.isAssignableFrom(aClass))
.map(aClass -> (Class) aClass)
.collect(Collectors.toList()); // TODO: pass a Supplier to toList() to avoid map
return Collections.unmodifiableCollection(classes);
}
public static Collection> getAnnotatedClasses(Class annotationClass, String... packageNames) {
List> classes = getClasses(packageNames).stream()
.filter(aClass -> aClass.isAnnotationPresent(annotationClass))
.collect(Collectors.toList());
return Collections.unmodifiableCollection(classes);
}
/**
* Extract the annotation from the controllerMethod or the declaring class.
*
* @param method
* @param annotationClass
* @param
* @return the annotation or null
*/
public static T getAnnotation(Method method, Class annotationClass) {
T annotation = method.getAnnotation(annotationClass);
if (annotation == null) {
annotation = getAnnotation(method.getDeclaringClass(), annotationClass);
}
return annotation;
}
public static T getAnnotation(Class objectClass, Class annotationClass) {
if (objectClass == null || Object.class == objectClass) {
return null;
}
T annotation = objectClass.getAnnotation(annotationClass);
if (annotation != null) {
return annotation;
}
return getAnnotation(objectClass.getSuperclass(), annotationClass);
}
/**
* Returns an array containing {@code Method} objects reflecting all the
* declared methods of the class or interface represented by this {@code
* Class} object, including public, protected, default (package)
* access, and private methods, but excluding inherited methods.
*
* This method differs from {@link Class#getDeclaredMethods()} since it
* does not return bridge methods, in other words, only the methods of
* the class are returned. If you just want the methods declared in
* {@code clazz} use this method!
*
* @param clazz Class
*
* @return the array of {@code Method} objects representing all the
* declared methods of this class
*
* @see Class#getDeclaredMethods()
*/
public static List getDeclaredMethods(Class clazz) {
return Arrays
.stream(clazz.getDeclaredMethods())
.filter(method -> !method.isBridge())
.collect(Collectors.toList());
}
public static List collectNestedAnnotation(Method method, Class annotationClass) {
List list = new ArrayList<>();
for (Annotation annotation : method.getDeclaredAnnotations()) {
if (annotation.annotationType().isAnnotationPresent(annotationClass)) {
T nestedAnnotation = annotation.annotationType().getAnnotation(annotationClass);
list.add(nestedAnnotation);
}
}
list.addAll(collectNestedAnnotation(method.getDeclaringClass(), annotationClass));
return list;
}
public static List collectNestedAnnotation(Class objectClass, Class annotationClass) {
if (objectClass == null || objectClass == Object.class) {
return Collections.emptyList();
}
List list = new ArrayList<>();
for (Annotation annotation : objectClass.getDeclaredAnnotations()) {
if (annotation.annotationType().isAnnotationPresent(annotationClass)) {
T nestedAnnotation = annotation.annotationType().getAnnotation(annotationClass);
list.add(nestedAnnotation);
}
}
list.addAll(collectNestedAnnotation(objectClass.getSuperclass(), annotationClass));
return list;
}
@SuppressWarnings("unchecked")
public static T executeDeclaredMethod(Object o, String methodName, Object... args) {
try {
Method method;
if (args != null && args.length > 0) {
Class[] types = new Class[args.length];
for (int i = 0; i < args.length; i++) {
types[i] = args[i].getClass();
}
method = o.getClass().getDeclaredMethod(methodName, types);
Objects.requireNonNull(method, String.format("Failed to find declared controllerMethod '%s' for args '{}' in type '%s'!",
methodName, types, o.getClass().getName()));
} else {
method = o.getClass().getDeclaredMethod(methodName);
Objects.requireNonNull(method, String.format("Failed to find declared controllerMethod '%s' in type '%s'!",
methodName, o.getClass().getName()));
}
return (T) method.invoke(o, args);
} catch (Exception e) {
throw new PippoRuntimeException("Failed to execute controllerMethod '{}' on object '{}'!", e, methodName);
}
}
public static List getResources(String name) {
List list = new ArrayList<>();
try {
Enumeration resources = ClassUtils.class.getClassLoader().getResources(name);
while (resources.hasMoreElements()) {
URL url = resources.nextElement();
list.add(url);
}
} catch (IOException e) {
throw new PippoRuntimeException(e);
}
return list;
}
public static boolean isAssignable(Object value, Class type) {
if (type.isInstance(value)) {
// inheritance
return true;
}
if (boolean.class == type && value instanceof Boolean) {
return true;
} else if (type.isPrimitive() && value instanceof Number) {
return true;
}
return false;
}
}