| /* |
| * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package java.beans; |
| |
| import java.lang.reflect.AccessibleObject; |
| import java.lang.reflect.Array; |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.security.AccessControlContext; |
| import java.security.AccessController; |
| import java.security.PrivilegedActionException; |
| import java.security.PrivilegedExceptionAction; |
| |
| import com.sun.beans.finder.ClassFinder; |
| import com.sun.beans.finder.ConstructorFinder; |
| import com.sun.beans.finder.MethodFinder; |
| import sun.reflect.misc.MethodUtil; |
| |
| import static sun.reflect.misc.ReflectUtil.checkPackageAccess; |
| |
| /** |
| * A {@code Statement} object represents a primitive statement |
| * in which a single method is applied to a target and |
| * a set of arguments - as in {@code "a.setFoo(b)"}. |
| * Note that where this example uses names |
| * to denote the target and its argument, a statement |
| * object does not require a name space and is constructed with |
| * the values themselves. |
| * The statement object associates the named method |
| * with its environment as a simple set of values: |
| * the target and an array of argument values. |
| * |
| * @since 1.4 |
| * |
| * @author Philip Milne |
| */ |
| public class Statement { |
| |
| private static Object[] emptyArray = new Object[]{}; |
| |
| static ExceptionListener defaultExceptionListener = new ExceptionListener() { |
| public void exceptionThrown(Exception e) { |
| System.err.println(e); |
| // e.printStackTrace(); |
| System.err.println("Continuing ..."); |
| } |
| }; |
| |
| private final AccessControlContext acc = AccessController.getContext(); |
| private final Object target; |
| private final String methodName; |
| private final Object[] arguments; |
| ClassLoader loader; |
| |
| /** |
| * Creates a new {@link Statement} object |
| * for the specified target object to invoke the method |
| * specified by the name and by the array of arguments. |
| * <p> |
| * The {@code target} and the {@code methodName} values should not be {@code null}. |
| * Otherwise an attempt to execute this {@code Expression} |
| * will result in a {@code NullPointerException}. |
| * If the {@code arguments} value is {@code null}, |
| * an empty array is used as the value of the {@code arguments} property. |
| * |
| * @param target the target object of this statement |
| * @param methodName the name of the method to invoke on the specified target |
| * @param arguments the array of arguments to invoke the specified method |
| */ |
| @ConstructorProperties({"target", "methodName", "arguments"}) |
| public Statement(Object target, String methodName, Object[] arguments) { |
| this.target = target; |
| this.methodName = methodName; |
| this.arguments = (arguments == null) ? emptyArray : arguments.clone(); |
| } |
| |
| /** |
| * Returns the target object of this statement. |
| * If this method returns {@code null}, |
| * the {@link #execute} method |
| * throws a {@code NullPointerException}. |
| * |
| * @return the target object of this statement |
| */ |
| public Object getTarget() { |
| return target; |
| } |
| |
| /** |
| * Returns the name of the method to invoke. |
| * If this method returns {@code null}, |
| * the {@link #execute} method |
| * throws a {@code NullPointerException}. |
| * |
| * @return the name of the method |
| */ |
| public String getMethodName() { |
| return methodName; |
| } |
| |
| /** |
| * Returns the arguments for the method to invoke. |
| * The number of arguments and their types |
| * must match the method being called. |
| * {@code null} can be used as a synonym of an empty array. |
| * |
| * @return the array of arguments |
| */ |
| public Object[] getArguments() { |
| return this.arguments.clone(); |
| } |
| |
| /** |
| * The {@code execute} method finds a method whose name is the same |
| * as the {@code methodName} property, and invokes the method on |
| * the target. |
| * |
| * When the target's class defines many methods with the given name |
| * the implementation should choose the most specific method using |
| * the algorithm specified in the Java Language Specification |
| * (15.11). The dynamic class of the target and arguments are used |
| * in place of the compile-time type information and, like the |
| * {@link java.lang.reflect.Method} class itself, conversion between |
| * primitive values and their associated wrapper classes is handled |
| * internally. |
| * <p> |
| * The following method types are handled as special cases: |
| * <ul> |
| * <li> |
| * Static methods may be called by using a class object as the target. |
| * <li> |
| * The reserved method name "new" may be used to call a class's constructor |
| * as if all classes defined static "new" methods. Constructor invocations |
| * are typically considered {@code Expression}s rather than {@code Statement}s |
| * as they return a value. |
| * <li> |
| * The method names "get" and "set" defined in the {@link java.util.List} |
| * interface may also be applied to array instances, mapping to |
| * the static methods of the same name in the {@code Array} class. |
| * </ul> |
| * |
| * @throws NullPointerException if the value of the {@code target} or |
| * {@code methodName} property is {@code null} |
| * @throws NoSuchMethodException if a matching method is not found |
| * @throws SecurityException if a security manager exists and |
| * it denies the method invocation |
| * @throws Exception that is thrown by the invoked method |
| * |
| * @see java.lang.reflect.Method |
| */ |
| public void execute() throws Exception { |
| invoke(); |
| } |
| |
| Object invoke() throws Exception { |
| AccessControlContext acc = this.acc; |
| if ((acc == null) && (System.getSecurityManager() != null)) { |
| throw new SecurityException("AccessControlContext is not set"); |
| } |
| try { |
| return AccessController.doPrivileged( |
| new PrivilegedExceptionAction<Object>() { |
| public Object run() throws Exception { |
| return invokeInternal(); |
| } |
| }, |
| acc |
| ); |
| } |
| catch (PrivilegedActionException exception) { |
| throw exception.getException(); |
| } |
| } |
| |
| private Object invokeInternal() throws Exception { |
| Object target = getTarget(); |
| String methodName = getMethodName(); |
| |
| if (target == null || methodName == null) { |
| throw new NullPointerException((target == null ? "target" : |
| "methodName") + " should not be null"); |
| } |
| |
| Object[] arguments = getArguments(); |
| if (arguments == null) { |
| arguments = emptyArray; |
| } else { |
| arguments = arguments.clone(); |
| } |
| if (target == Class.class && methodName.equals("forName")) { |
| final String name = (String) arguments[0]; |
| if (arguments.length == 1) { |
| // Class.forName(String className) won't load classes outside |
| // of core from a class inside core. Special |
| // case this method. |
| // checkPackageAccess(name) will be called by ClassFinder |
| return ClassFinder.resolveClass(name, this.loader); |
| } |
| // The 3 args Class.forName(String className, boolean, classloader) |
| // requires getClassLoader permission, but we will be stricter and |
| // will require access to the package as well. |
| checkPackageAccess(name); |
| } |
| Class<?>[] argClasses = new Class<?>[arguments.length]; |
| for(int i = 0; i < arguments.length; i++) { |
| argClasses[i] = (arguments[i] == null) ? null : arguments[i].getClass(); |
| } |
| |
| AccessibleObject m = null; |
| if (target instanceof Class) { |
| /* |
| For class methods, simluate the effect of a meta class |
| by taking the union of the static methods of the |
| actual class, with the instance methods of "Class.class" |
| and the overloaded "newInstance" methods defined by the |
| constructors. |
| This way "System.class", for example, will perform both |
| the static method getProperties() and the instance method |
| getSuperclass() defined in "Class.class". |
| */ |
| if (methodName.equals("new")) { |
| methodName = "newInstance"; |
| } |
| // Provide a short form for array instantiation by faking an nary-constructor. |
| if (methodName.equals("newInstance") && ((Class)target).isArray()) { |
| Object result = Array.newInstance(((Class)target).getComponentType(), arguments.length); |
| for(int i = 0; i < arguments.length; i++) { |
| Array.set(result, i, arguments[i]); |
| } |
| return result; |
| } |
| if (methodName.equals("newInstance") && arguments.length != 0) { |
| // The Character class, as of 1.4, does not have a constructor |
| // which takes a String. All of the other "wrapper" classes |
| // for Java's primitive types have a String constructor so we |
| // fake such a constructor here so that this special case can be |
| // ignored elsewhere. |
| if (target == Character.class && arguments.length == 1 && |
| argClasses[0] == String.class) { |
| return ((String)arguments[0]).charAt(0); |
| } |
| try { |
| m = ConstructorFinder.findConstructor((Class)target, argClasses); |
| } |
| catch (NoSuchMethodException exception) { |
| m = null; |
| } |
| } |
| if (m == null && target != Class.class) { |
| m = getMethod((Class)target, methodName, argClasses); |
| } |
| if (m == null) { |
| m = getMethod(Class.class, methodName, argClasses); |
| } |
| } |
| else { |
| /* |
| This special casing of arrays is not necessary, but makes files |
| involving arrays much shorter and simplifies the archiving infrastrcure. |
| The Array.set() method introduces an unusual idea - that of a static method |
| changing the state of an instance. Normally statements with side |
| effects on objects are instance methods of the objects themselves |
| and we reinstate this rule (perhaps temporarily) by special-casing arrays. |
| */ |
| if (target.getClass().isArray() && |
| (methodName.equals("set") || methodName.equals("get"))) { |
| int index = ((Integer)arguments[0]).intValue(); |
| if (methodName.equals("get")) { |
| return Array.get(target, index); |
| } |
| else { |
| Array.set(target, index, arguments[1]); |
| return null; |
| } |
| } |
| m = getMethod(target.getClass(), methodName, argClasses); |
| } |
| if (m != null) { |
| try { |
| if (m instanceof Method) { |
| return MethodUtil.invoke((Method)m, target, arguments); |
| } |
| else { |
| return ((Constructor)m).newInstance(arguments); |
| } |
| } |
| catch (IllegalAccessException iae) { |
| throw new Exception("Statement cannot invoke: " + |
| methodName + " on " + target.getClass(), |
| iae); |
| } |
| catch (InvocationTargetException ite) { |
| Throwable te = ite.getTargetException(); |
| if (te instanceof Exception) { |
| throw (Exception)te; |
| } |
| else { |
| throw ite; |
| } |
| } |
| } |
| throw new NoSuchMethodException(toString()); |
| } |
| |
| String instanceName(Object instance) { |
| if (instance == null) { |
| return "null"; |
| } else if (instance.getClass() == String.class) { |
| return "\""+(String)instance + "\""; |
| } else { |
| // Note: there is a minor problem with using the non-caching |
| // NameGenerator method. The return value will not have |
| // specific information about the inner class name. For example, |
| // In 1.4.2 an inner class would be represented as JList$1 now |
| // would be named Class. |
| |
| return NameGenerator.unqualifiedClassName(instance.getClass()); |
| } |
| } |
| |
| /** |
| * Prints the value of this statement using a Java-style syntax. |
| */ |
| public String toString() { |
| // Respect a subclass's implementation here. |
| Object target = getTarget(); |
| String methodName = getMethodName(); |
| Object[] arguments = getArguments(); |
| if (arguments == null) { |
| arguments = emptyArray; |
| } |
| StringBuilder result = new StringBuilder(instanceName(target) + "." + methodName + "("); |
| int n = arguments.length; |
| for(int i = 0; i < n; i++) { |
| result.append(instanceName(arguments[i])); |
| if (i != n -1) { |
| result.append(", "); |
| } |
| } |
| result.append(");"); |
| return result.toString(); |
| } |
| |
| static Method getMethod(Class<?> type, String name, Class<?>... args) { |
| try { |
| return MethodFinder.findMethod(type, name, args); |
| } |
| catch (NoSuchMethodException exception) { |
| return null; |
| } |
| } |
| } |