dubbo-rpc-extensions/dubbo-rpc-rest/src/main/java/org/apache/dubbo/rpc/protocol/rest/util/ReflectUtils.java

/*
 * 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.dubbo.rpc.protocol.rest.util;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class ReflectUtils {

    public static Class findClass(String name, ClassLoader classLoader) throws ClassNotFoundException {

        return classLoader.loadClass(name);
    }

    public static Class findClass(String name) throws ClassNotFoundException {

        return findClass(Thread.currentThread().getContextClassLoader(), name);
    }

    public static Class findClassAndTryCatch(String name, ClassLoader classLoader) {

        try {
            return findClass(name, classLoader);
        } catch (Throwable e) {

        }
        return null;
    }

    public static Class findClass(ClassLoader classLoader, String... name) throws ClassNotFoundException {

        String[] names = name;

        Class tmp;
        for (String s : names) {
            tmp = findClassAndTryCatch(s, classLoader);
            if (tmp == null) {
                continue;
            } else {
                return tmp;
            }
        }
        throw new ClassNotFoundException();
    }

    public static Class findClassTryException(ClassLoader classLoader, String... name) {

        try {
            return findClass(classLoader, name);
        } catch (Exception e) {

        }
        return null;
    }

    public static List<Method> getMethodByNameList(Class clazz, String name) {

        return getMethodByNameList(clazz, name, false);
    }

    public static List<Method> getMethodByNameList(Class clazz, String name, boolean declare) {
        // prevent duplicate method
        Set<Method> methods = new HashSet<>();

        try {
            filterMethod(name, methods, clazz.getDeclaredMethods());

        } catch (Exception e) {

        }

        if (!declare) {
            return new ArrayList<>(methods);
        }

        try {
            filterMethod(name, methods, clazz.getMethods());
        } catch (Exception e) {

        }

        return new ArrayList<>(methods);
    }

    public static List<Constructor<?>> getConstructList(Class clazz) {
        // prevent duplicate method
        Set<Constructor<?>> methods = new HashSet<>();

        try {
            filterConstructMethod(methods, clazz.getDeclaredConstructors());
        } catch (Exception e) {
        }

        try {
            filterConstructMethod(methods, clazz.getConstructors());
        } catch (Exception e) {

        }
        return new ArrayList<>(methods);
    }

    private static void filterConstructMethod(Set<Constructor<?>> methods, Constructor<?>[] declaredMethods) {
        for (Constructor<?> constructor : declaredMethods) {
            methods.add(constructor);
        }
    }

    private static void filterMethod(String name, Set<Method> methodList, Method[] methods) {
        for (Method declaredMethod : methods) {
            if (!name.equals(declaredMethod.getName())) {
                continue;
            }
            declaredMethod.setAccessible(true);
            methodList.add(declaredMethod);
        }
    }

    public static Method getMethodByName(Class clazz, String name) {

        List<Method> methodByNameList = getMethodByNameList(clazz, name, true);
        if (methodByNameList.isEmpty()) {
            return null;
        } else {
            return methodByNameList.get(0);
        }
    }

    public static Class findClassTryException(String... name) {
        return findClassTryException(Thread.currentThread().getContextClassLoader(), name);
    }

    public static Object invoke(Object object, Method method, Object[] params)
            throws InvocationTargetException, IllegalAccessException {
        return method.invoke(object, params);
    }

    public static Object invokeAndTryCatch(Object object, Method method, Object[] params) {
        try {
            return invoke(object, method, params);
        } catch (Exception e) {

        }

        return null;
    }
}