| // Copyright 2015 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package org.chromium.incrementalinstall; |
| |
| import java.lang.reflect.Array; |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.Field; |
| import java.lang.reflect.Method; |
| import java.util.Arrays; |
| |
| /** |
| * Reflection helper methods. |
| */ |
| final class Reflect { |
| /** |
| * Sets the value of an object's field (even if it's not visible). |
| * |
| * @param instance The object containing the field to set. |
| * @param name The name of the field to set. |
| * @param value The new value for the field. |
| */ |
| static void setField(Object instance, String name, Object value) |
| throws ReflectiveOperationException { |
| Field field = findField(instance, name); |
| field.setAccessible(true); |
| field.set(instance, value); |
| } |
| |
| /** |
| * Retrieves the value of an object's field (even if it's not visible). |
| * |
| * @param instance The object containing the field to set. |
| * @param name The name of the field to set. |
| * @return The field's value. Primitive values are returned as their boxed |
| * type. |
| */ |
| static Object getField(Object instance, String name) throws ReflectiveOperationException { |
| Field field = findField(instance, name); |
| field.setAccessible(true); |
| return field.get(instance); |
| } |
| |
| /** |
| * Concatenates two arrays into a new array. The arrays must be of the same |
| * type. |
| */ |
| static Object[] concatArrays(Object[] arrType, Object[] left, Object[] right) { |
| Object[] result = (Object[]) Array.newInstance( |
| arrType.getClass().getComponentType(), left.length + right.length); |
| System.arraycopy(left, 0, result, 0, left.length); |
| System.arraycopy(right, 0, result, left.length, right.length); |
| return result; |
| } |
| |
| /** |
| * Invokes a method with zero or more parameters. For static methods, use the Class as the |
| * instance. |
| */ |
| static Object invokeMethod(Object instance, String name, Object... params) |
| throws ReflectiveOperationException { |
| boolean isStatic = instance instanceof Class; |
| Class<?> clazz = isStatic ? (Class<?>) instance : instance.getClass(); |
| Method method = findMethod(clazz, name, params); |
| method.setAccessible(true); |
| return method.invoke(instance, params); |
| } |
| |
| /** |
| * Calls a constructor with zero or more parameters. |
| */ |
| static Object newInstance(Class<?> clazz, Object... params) |
| throws ReflectiveOperationException { |
| Constructor<?> constructor = findConstructor(clazz, params); |
| constructor.setAccessible(true); |
| return constructor.newInstance(params); |
| } |
| |
| private static Field findField(Object instance, String name) throws NoSuchFieldException { |
| boolean isStatic = instance instanceof Class; |
| Class<?> clazz = isStatic ? (Class<?>) instance : instance.getClass(); |
| for (; clazz != null; clazz = clazz.getSuperclass()) { |
| try { |
| return clazz.getDeclaredField(name); |
| } catch (NoSuchFieldException e) { |
| // Need to look in the super class. |
| } |
| } |
| throw new NoSuchFieldException("Field " + name + " not found in " + instance.getClass()); |
| } |
| |
| private static Method findMethod(Class<?> clazz, String name, Object... params) |
| throws NoSuchMethodException { |
| for (; clazz != null; clazz = clazz.getSuperclass()) { |
| for (Method method : clazz.getDeclaredMethods()) { |
| if (method.getName().equals(name) |
| && areParametersCompatible(method.getParameterTypes(), params)) { |
| return method; |
| } |
| } |
| } |
| throw new NoSuchMethodException("Method " + name + " with parameters " |
| + Arrays.asList(params) + " not found in " + clazz); |
| } |
| |
| private static Constructor<?> findConstructor(Class<?> clazz, Object... params) |
| throws NoSuchMethodException { |
| for (Constructor<?> constructor : clazz.getDeclaredConstructors()) { |
| if (areParametersCompatible(constructor.getParameterTypes(), params)) { |
| return constructor; |
| } |
| } |
| throw new NoSuchMethodException("Constructor with parameters " + Arrays.asList(params) |
| + " not found in " + clazz); |
| } |
| |
| private static boolean areParametersCompatible(Class<?>[] paramTypes, Object... params) { |
| if (params.length != paramTypes.length) { |
| return false; |
| } |
| for (int i = 0; i < params.length; i++) { |
| if (!isAssignableFrom(paramTypes[i], params[i])) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private static boolean isAssignableFrom(Class<?> left, Object right) { |
| if (right == null) { |
| return !left.isPrimitive(); |
| } |
| Class<?> rightClazz = right.getClass(); |
| if (left.isPrimitive()) { |
| // TODO(agrieve): Fill in the rest as needed. |
| return left == boolean.class && rightClazz == Boolean.class |
| || left == int.class && rightClazz == Integer.class; |
| } |
| return left.isAssignableFrom(rightClazz); |
| } |
| } |