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Diffstat (limited to 'libjava/classpath/java/beans/Statement.java')
| -rw-r--r-- | libjava/classpath/java/beans/Statement.java | 386 |
1 files changed, 0 insertions, 386 deletions
diff --git a/libjava/classpath/java/beans/Statement.java b/libjava/classpath/java/beans/Statement.java deleted file mode 100644 index d9cd304..0000000 --- a/libjava/classpath/java/beans/Statement.java +++ /dev/null @@ -1,386 +0,0 @@ -/* Statement.java - Copyright (C) 2004, 2005, 2006, Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath 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 for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package java.beans; - -import gnu.java.lang.CPStringBuilder; - -import java.lang.reflect.Array; -import java.lang.reflect.Constructor; -import java.lang.reflect.Method; - -/** - * <p>A Statement captures the execution of an object method. It stores - * the object, the method to call, and the arguments to the method and - * provides the ability to execute the method on the object, using the - * provided arguments.</p> - * - * @author Jerry Quinn (jlquinn@optonline.net) - * @author Robert Schuster (robertschuster@fsfe.org) - * @since 1.4 - */ -public class Statement -{ - private Object target; - private String methodName; - private Object[] arguments; - - /** - * One or the other of these will get a value after execute is - * called once, but not both. - */ - private transient Method method; - private transient Constructor ctor; - - /** - * <p>Constructs a statement representing the invocation of - * object.methodName(arg[0], arg[1], ...);</p> - * - * <p>If the argument array is null it is replaced with an - * array of zero length.</p> - * - * @param target The object to invoke the method on. - * @param methodName The object method to invoke. - * @param arguments An array of arguments to pass to the method. - */ - public Statement(Object target, String methodName, Object[] arguments) - { - this.target = target; - this.methodName = methodName; - this.arguments = (arguments != null) ? arguments : new Object[0]; - } - - /** - * Execute the statement. - * - * <p>Finds the specified method in the target object and calls it with - * the arguments given in the constructor.</p> - * - * <p>The most specific method according to the JLS(15.11) is used when - * there are multiple methods with the same name.</p> - * - * <p>Execute performs some special handling for methods and - * parameters: - * <ul> - * <li>Static methods can be executed by providing the class as a - * target.</li> - * - * <li>The method name new is reserved to call the constructor - * new() will construct an object and return it. Not useful unless - * an expression :-)</li> - * - * <li>If the target is an array, get and set as defined in - * java.util.List are recognized as valid methods and mapped to the - * methods of the same name in java.lang.reflect.Array.</li> - * - * <li>The native datatype wrappers Boolean, Byte, Character, Double, - * Float, Integer, Long, and Short will map to methods that have - * native datatypes as parameters, in the same way as Method.invoke. - * However, these wrappers also select methods that actually take - * the wrapper type as an argument.</li> - * </ul> - * </p> - * - * <p>The Sun spec doesn't deal with overloading between int and - * Integer carefully. If there are two methods, one that takes an - * Integer and the other taking an int, the method chosen is not - * specified, and can depend on the order in which the methods are - * declared in the source file.</p> - * - * @throws Exception if an exception occurs while locating or - * invoking the method. - */ - public void execute() throws Exception - { - doExecute(); - } - - private static Class wrappers[] = - { - Boolean.class, Byte.class, Character.class, Double.class, Float.class, - Integer.class, Long.class, Short.class - }; - - private static Class natives[] = - { - Boolean.TYPE, Byte.TYPE, Character.TYPE, Double.TYPE, Float.TYPE, - Integer.TYPE, Long.TYPE, Short.TYPE - }; - - /** Given a wrapper class, return the native class for it. - * <p>For example, if <code>c</code> is <code>Integer</code>, - * <code>Integer.TYPE</code> is returned.</p> - */ - private Class unwrap(Class c) - { - for (int i = 0; i < wrappers.length; i++) - if (c == wrappers[i]) - return natives[i]; - return null; - } - - /** Returns <code>true</code> if all args can be assigned to - * <code>params</code>, <code>false</code> otherwise. - * - * <p>Arrays are guaranteed to be the same length.</p> - */ - private boolean compatible(Class[] params, Class[] args) - { - for (int i = 0; i < params.length; i++) - { - // Argument types are derived from argument values. If one of them was - // null then we cannot deduce its type. However null can be assigned to - // any type. - if (args[i] == null) - continue; - - // Treat Integer like int if appropriate - Class nativeType = unwrap(args[i]); - if (nativeType != null && params[i].isPrimitive() - && params[i].isAssignableFrom(nativeType)) - continue; - if (params[i].isAssignableFrom(args[i])) - continue; - - return false; - } - return true; - } - - /** - * Returns <code>true</code> if the method arguments in first are - * more specific than the method arguments in second, i.e. all - * arguments in <code>first</code> can be assigned to those in - * <code>second</code>. - * - * <p>A method is more specific if all parameters can also be fed to - * the less specific method, because, e.g. the less specific method - * accepts a base class of the equivalent argument for the more - * specific one.</p> - * - * @param first a <code>Class[]</code> value - * @param second a <code>Class[]</code> value - * @return a <code>boolean</code> value - */ - private boolean moreSpecific(Class[] first, Class[] second) - { - for (int j=0; j < first.length; j++) - { - if (second[j].isAssignableFrom(first[j])) - continue; - return false; - } - return true; - } - - final Object doExecute() throws Exception - { - Class klazz = (target instanceof Class) - ? (Class) target : target.getClass(); - Object args[] = (arguments == null) ? new Object[0] : arguments; - Class argTypes[] = new Class[args.length]; - - // Retrieve type or use null if the argument is null. The null argument - // type is later used in compatible(). - for (int i = 0; i < args.length; i++) - argTypes[i] = (args[i] != null) ? args[i].getClass() : null; - - if (target.getClass().isArray()) - { - // FIXME: invoke may have to be used. For now, cast to Number - // and hope for the best. If caller didn't behave, we go boom - // and throw the exception. - if (methodName.equals("get") && argTypes.length == 1) - return Array.get(target, ((Number)args[0]).intValue()); - if (methodName.equals("set") && argTypes.length == 2) - { - Object obj = Array.get(target, ((Number)args[0]).intValue()); - Array.set(target, ((Number)args[0]).intValue(), args[1]); - return obj; - } - throw new NoSuchMethodException("No matching method for statement " + toString()); - } - - // If we already cached the method, just use it. - if (method != null) - return method.invoke(target, args); - else if (ctor != null) - return ctor.newInstance(args); - - // Find a matching method to call. JDK seems to go through all - // this to find the method to call. - - // if method name or length don't match, skip - // Need to go through each arg - // If arg is wrapper - check if method arg is matchable builtin - // or same type or super - // - check that method arg is same or super - - if (methodName.equals("new") && target instanceof Class) - { - Constructor ctors[] = klazz.getConstructors(); - for (int i = 0; i < ctors.length; i++) - { - // Skip methods with wrong number of args. - Class ptypes[] = ctors[i].getParameterTypes(); - - if (ptypes.length != args.length) - continue; - - // Check if method matches - if (!compatible(ptypes, argTypes)) - continue; - - // Use method[i] if it is more specific. - // FIXME: should this check both directions and throw if - // neither is more specific? - if (ctor == null) - { - ctor = ctors[i]; - continue; - } - Class mptypes[] = ctor.getParameterTypes(); - if (moreSpecific(ptypes, mptypes)) - ctor = ctors[i]; - } - if (ctor == null) - throw new InstantiationException("No matching constructor for statement " + toString()); - return ctor.newInstance(args); - } - - Method methods[] = klazz.getMethods(); - - for (int i = 0; i < methods.length; i++) - { - // Skip methods with wrong name or number of args. - if (!methods[i].getName().equals(methodName)) - continue; - Class ptypes[] = methods[i].getParameterTypes(); - if (ptypes.length != args.length) - continue; - - // Check if method matches - if (!compatible(ptypes, argTypes)) - continue; - - // Use method[i] if it is more specific. - // FIXME: should this check both directions and throw if - // neither is more specific? - if (method == null) - { - method = methods[i]; - continue; - } - Class mptypes[] = method.getParameterTypes(); - if (moreSpecific(ptypes, mptypes)) - method = methods[i]; - } - if (method == null) - throw new NoSuchMethodException("No matching method for statement " + toString()); - - // If we were calling Class.forName(String) we intercept and call the - // forName-variant that allows a ClassLoader argument. We take the - // system classloader (aka application classloader) here to make sure - // that application defined classes can be resolved. If we would not - // do that the Class.forName implementation would use the class loader - // of java.beans.Statement which is <null> and cannot resolve application - // defined classes. - if (method.equals( - Class.class.getMethod("forName", new Class[] { String.class }))) - return Class.forName( - (String) args[0], true, ClassLoader.getSystemClassLoader()); - - try { - return method.invoke(target, args); - } catch(IllegalArgumentException iae){ - System.err.println("method: " + method); - - for(int i=0;i<args.length;i++){ - System.err.println("args[" + i + "]: " + args[i]); - } - throw iae; - } - } - - - - /** Return the statement arguments. */ - public Object[] getArguments() { return arguments; } - - /** Return the statement method name. */ - public String getMethodName() { return methodName; } - - /** Return the statement object. */ - public Object getTarget() { return target; } - - /** - * Returns a string representation of this <code>Statement</code>. - * - * @return A string representation of this <code>Statement</code>. - */ - public String toString() - { - CPStringBuilder result = new CPStringBuilder(); - - String targetName; - if (target != null) - targetName = target.getClass().getSimpleName(); - else - targetName = "null"; - - result.append(targetName); - result.append("."); - result.append(methodName); - result.append("("); - - String sep = ""; - for (int i = 0; i < arguments.length; i++) - { - result.append(sep); - result.append( - ( arguments[i] == null ) ? "null" : - ( arguments[i] instanceof String ) ? "\"" + arguments[i] + "\"" : - arguments[i].getClass().getSimpleName()); - sep = ", "; - } - result.append(");"); - - return result.toString(); - } - -} |