/* * Copyright (C) 2011 The Android Open Source Project * * 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. */ import java.lang.reflect.*; import java.util.*; class Main { private static boolean z = true; private static byte b = 8; private static char c = '\u2714'; private static double d = Math.PI; private static float f = 3.14f; private static int i = 32; private static long j = 0x0123456789abcdefL; private static short s = 16; public static void testFieldReflection() throws Exception { Field f; f = Main.class.getDeclaredField("z"); System.out.println(f.getBoolean(null)); f = Main.class.getDeclaredField("b"); System.out.println(f.getByte(null)); f = Main.class.getDeclaredField("c"); System.out.println(f.getChar(null)); f = Main.class.getDeclaredField("d"); System.out.println(f.getDouble(null)); f = Main.class.getDeclaredField("f"); System.out.println(f.getFloat(null)); f = Main.class.getDeclaredField("i"); System.out.println(f.getInt(null)); f = Main.class.getDeclaredField("j"); System.out.println(f.getLong(null)); f = Main.class.getDeclaredField("s"); System.out.println(f.getShort(null)); f = Main.class.getDeclaredField("z"); f.setBoolean(null, false); f = Main.class.getDeclaredField("b"); f.setByte(null, (byte) 7); f = Main.class.getDeclaredField("c"); f.setChar(null, 'y'); f = Main.class.getDeclaredField("d"); f.setDouble(null, 2.7); f = Main.class.getDeclaredField("f"); f.setFloat(null, 2.7f); f = Main.class.getDeclaredField("i"); f.setInt(null, 31); f = Main.class.getDeclaredField("j"); f.setLong(null, 63); f = Main.class.getDeclaredField("s"); f.setShort(null, (short) 15); f = Main.class.getDeclaredField("z"); System.out.println(f.getBoolean(null)); f = Main.class.getDeclaredField("b"); System.out.println(f.getByte(null)); f = Main.class.getDeclaredField("c"); System.out.println(f.getChar(null)); f = Main.class.getDeclaredField("d"); System.out.println(f.getDouble(null)); f = Main.class.getDeclaredField("f"); System.out.println(f.getFloat(null)); f = Main.class.getDeclaredField("i"); System.out.println(f.getInt(null)); f = Main.class.getDeclaredField("j"); System.out.println(f.getLong(null)); f = Main.class.getDeclaredField("s"); System.out.println(f.getShort(null)); f = Main.class.getDeclaredField("z"); f.set(null, Boolean.valueOf(true)); f = Main.class.getDeclaredField("b"); f.set(null, Byte.valueOf((byte) 6)); f = Main.class.getDeclaredField("c"); f.set(null, Character.valueOf('z')); f = Main.class.getDeclaredField("d"); f.set(null, Double.valueOf(1.3)); f = Main.class.getDeclaredField("f"); f.set(null, Float.valueOf(1.3f)); f = Main.class.getDeclaredField("i"); f.set(null, Integer.valueOf(30)); f = Main.class.getDeclaredField("j"); f.set(null, Long.valueOf(62)); f.set(null, Integer.valueOf(62)); f = Main.class.getDeclaredField("s"); f.set(null, Short.valueOf((short) 14)); f = Main.class.getDeclaredField("z"); System.out.println(f.getBoolean(null)); f = Main.class.getDeclaredField("b"); System.out.println(f.getByte(null)); f = Main.class.getDeclaredField("c"); System.out.println(f.getChar(null)); f = Main.class.getDeclaredField("d"); System.out.println(f.getDouble(null)); f = Main.class.getDeclaredField("f"); System.out.println(f.getFloat(null)); f = Main.class.getDeclaredField("i"); System.out.println(f.getInt(null)); f = Main.class.getDeclaredField("j"); System.out.println(f.getLong(null)); f = Main.class.getDeclaredField("s"); System.out.println(f.getShort(null)); try { f = Main.class.getDeclaredField("s"); f.set(null, Integer.valueOf(14)); System.out.println("************* should have thrown!"); } catch (IllegalArgumentException expected) { System.out.println("got expected IllegalArgumentException"); } f = Main.class.getDeclaredField("z"); show(f.get(null)); f = Main.class.getDeclaredField("b"); show(f.get(null)); f = Main.class.getDeclaredField("c"); show(f.get(null)); f = Main.class.getDeclaredField("d"); show(f.get(null)); f = Main.class.getDeclaredField("f"); show(f.get(null)); f = Main.class.getDeclaredField("i"); show(f.get(null)); f = Main.class.getDeclaredField("j"); show(f.get(null)); f = Main.class.getDeclaredField("s"); show(f.get(null)); /* private static boolean z = true; private static byte b = 8; private static char c = '\u2714'; private static double d = Math.PI; private static float f = 3.14f; private static int i = 32; private static long j = 0x0123456789abcdefL; private static short s = 16; */ } private static void show(Object o) { System.out.println(o + " (" + (o != null ? o.getClass() : "null") + ")"); } /** * Sorts the input array using the comparator and returns the sorted array. */ private static Object[] sort(Object[] objects, Comparator<Object> comp) { Arrays.sort(objects, comp); return objects; } public static void testMethodReflection() throws Exception { Comparator<Object> comp = new Comparator<Object>() { public int compare(Object a, Object b) { return a.toString().compareTo(b.toString()); } public boolean equals(Object b) { return this == b; } }; // Sort the return values by their string values since the order is undefined by the spec. System.out.println(Arrays.toString(sort(String.class.getDeclaredConstructors(), comp))); System.out.println(Arrays.toString(sort(String.class.getDeclaredFields(), comp))); System.out.println(Arrays.toString(sort(String.class.getDeclaredMethods(), comp))); System.out.println(Arrays.toString(Main.class.getInterfaces())); System.out.println(Arrays.toString(String.class.getInterfaces())); System.out.println(Main.class.getModifiers()); System.out.println(String.class.getModifiers()); System.out.println(String.class.isAssignableFrom(Object.class)); System.out.println(Object.class.isAssignableFrom(String.class)); System.out.println(String.class.isInstance("hello")); System.out.println(String.class.isInstance(123)); Method m; m = Main.class.getDeclaredMethod("IV", int.class); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null, 4444)); System.out.println(Arrays.toString(m.getParameterTypes())); m = Main.class.getDeclaredMethod("IIV", int.class, int.class); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null, 1111, 2222)); m = Main.class.getDeclaredMethod("III", int.class, int.class); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null, 1111, 2222)); m = Main.class.getDeclaredMethod("sumArray", int[].class); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null, new int[] { 1, 2, 3, 4 })); m = Main.class.getDeclaredMethod("concat", String[].class); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null, (Object) new String[] { "h", "e", "l", "l", "o" })); m = Main.class.getDeclaredMethod("ZBCDFIJSV", boolean.class, byte.class, char.class, double.class, float.class, int.class, long.class, short.class); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null, true, (byte) 0, '1', 2, 3, 4, 5, (short) 6)); m = Main.class.getDeclaredMethod("ZBCDLFIJSV", boolean.class, byte.class, char.class, double.class, String.class, float.class, int.class, long.class, short.class); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null, true, (byte) 0, '1', 2, "hello world", 3, 4, 5, (short) 6)); try { m = Main.class.getDeclaredMethod("thrower"); System.out.println(Arrays.toString(m.getParameterTypes())); show(m.invoke(null)); System.out.println("************* should have thrown!"); } catch (InvocationTargetException expected) { System.out.println("got expected InvocationTargetException"); } } private static void thrower() { throw new ArithmeticException("surprise!"); } private static int sumArray(int[] xs) { int result = 0; for (int x : xs) { result += x; } return result; } private static String concat(String[] strings) { String result = ""; for (String s : strings) { result += s; } return result; } private static void IV(int i) { System.out.println(i); } private static void IIV(int i, int j) { System.out.println(i + " " + j); } private static int III(int i, int j) { System.out.println(i + " " + j); return i + j; } private static void ZBCDFIJSV(boolean z, byte b, char c, double d, float f, int i, long l, short s) { System.out.println(z + " " + b + " " + c + " " + d + " " + f + " " + i + " " + l + " " + s); } private static void ZBCDLFIJSV(boolean z, byte b, char c, double d, String string, float f, int i, long l, short s) { System.out.println(z + " " + b + " " + c + " " + d + " " + " " + string + " " + f + " " + i + " " + l + " " + s); } public static void testConstructorReflection() throws Exception { Constructor<String> ctor = String.class.getConstructor(); show(ctor.newInstance()); ctor = String.class.getConstructor(char[].class, int.class, int.class); show(ctor.newInstance(new char[] { '\u2714', 'y', 'z', '!' }, 1, 2)); } private static void testPackagePrivateConstructor() { try { Class<?> c = Class.forName("sub.PPClass"); Constructor<?> cons = c.getConstructor(); cons.newInstance(); throw new RuntimeException("Expected IllegalAccessException."); } catch (IllegalAccessException e) { // Expected. } catch (Exception e) { // Error. e.printStackTrace(System.out); } } private static void testPackagePrivateAccessibleConstructor() { try { Class<?> c = Class.forName("sub.PPClass"); Constructor<?> cons = c.getConstructor(); cons.setAccessible(true); // ensure we prevent IllegalAccessException cons.newInstance(); } catch (Exception e) { // Error. e.printStackTrace(System.out); } } public static void main(String[] args) throws Exception { testFieldReflection(); testMethodReflection(); testConstructorReflection(); testPackagePrivateConstructor(); testPackagePrivateAccessibleConstructor(); } }