org.apache.pulsar.client.admin.utils.ReflectionUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.pulsar.client.admin.utils;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import lombok.experimental.UtilityClass;
@UtilityClass
public class ReflectionUtils {
interface SupplierWithException {
T get() throws Exception;
}
public static T newBuilder(String className) {
return catchExceptions(
() -> (T) ReflectionUtils.getStaticMethod(
className, "builder", null)
.invoke(null, null));
}
static T catchExceptions(SupplierWithException s) {
try {
return s.get();
} catch (Throwable t) {
if (t instanceof InvocationTargetException) {
// exception is thrown during invocation
Throwable cause = t.getCause();
if (cause instanceof RuntimeException) {
throw (RuntimeException) cause;
} else {
throw new RuntimeException(cause);
}
}
throw new RuntimeException(t);
}
}
@SuppressWarnings("unchecked")
static Class newClassInstance(String className) {
try {
try {
// when the API is loaded in the same classloader as the impl
return (Class) DefaultImplementation.class.getClassLoader().loadClass(className);
} catch (Exception e) {
// when the API is loaded in a separate classloader as the impl
// the classloader that loaded the impl needs to be a child classloader of the classloader
// that loaded the API
return (Class) Thread.currentThread().getContextClassLoader().loadClass(className);
}
} catch (ClassNotFoundException | NoClassDefFoundError e) {
throw new RuntimeException(e);
}
}
static Constructor getConstructor(String className, Class... argTypes) {
try {
Class clazz = newClassInstance(className);
return clazz.getConstructor(argTypes);
} catch (NoSuchMethodException e) {
throw new RuntimeException(e);
}
}
static Method getStaticMethod(String className, String method, Class... argTypes) {
try {
Class clazz = newClassInstance(className);
return clazz.getMethod(method, argTypes);
} catch (NoSuchMethodException e) {
throw new RuntimeException(e);
}
}
}