ReflectionUtil.java — netty Source File

Source Code

/*
 * Copyright 2017 The Netty Project
 *
 * The Netty Project 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:
 *
 *   https://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 io.netty.util.internal;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Array;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;

public final class ReflectionUtil {

    private ReflectionUtil() { }

    /**
     * Try to call {@link AccessibleObject#setAccessible(boolean)} but will catch any {@link SecurityException} and
     * {@link java.lang.reflect.InaccessibleObjectException} and return it.
     * The caller must check if it returns {@code null} and if not handle the returned exception.
     */
    public static Throwable trySetAccessible(AccessibleObject object, boolean checkAccessible) {
        if (checkAccessible && !PlatformDependent0.isExplicitTryReflectionSetAccessible()) {
            return new UnsupportedOperationException("Reflective setAccessible(true) disabled");
        }
        try {
            object.setAccessible(true);
            return null;
        } catch (SecurityException e) {
            return e;
        } catch (RuntimeException e) {
            return handleInaccessibleObjectException(e);
        }
    }

    private static RuntimeException handleInaccessibleObjectException(RuntimeException e) {
        // JDK 9 can throw an inaccessible object exception here; since Netty compiles
        // against JDK 7 and this exception was only added in JDK 9, we have to weakly
        // check the type
        if ("java.lang.reflect.InaccessibleObjectException".equals(e.getClass().getName())) {
            return e;
        }
        throw e;
    }

    private static Class<?> fail(Class<?> type, String typeParamName) {
        throw new IllegalStateException(
                "cannot determine the type of the type parameter '" + typeParamName + "': " + type);
// ... (80 more lines)