/* * JavaObject.java * * Copyright (C) 2002-2005 Peter Graves * $Id$ * * This program 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 * of the License, or (at your option) any later version. * * This program 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 this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * 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 org.armedbear.lisp; import static org.armedbear.lisp.Lisp.*; import java.lang.reflect.Array; import java.lang.reflect.Field; import java.math.BigInteger; import java.util.*; public final class JavaObject extends LispObject { final Object obj; private final Class intendedClass; public JavaObject(Object obj) { this.obj = obj; this.intendedClass = obj != null ? Java.maybeBoxClass(obj.getClass()) : null; } public static final Symbol JAVA_CLASS_JCLASS = PACKAGE_JAVA.intern("JAVA-CLASS-JCLASS"); public static final Symbol JAVA_CLASS = PACKAGE_JAVA.intern("JAVA-CLASS"); public static final Symbol ENSURE_JAVA_CLASS = PACKAGE_JAVA.intern("ENSURE-JAVA-CLASS"); /** * Constructs a Java Object with the given intended class, used to access * the object reflectively. If the class represents a primitive type, * the corresponding wrapper type is used instead. * @throws ClassCastException if the object is not an instance of the * intended class. */ public JavaObject(Object obj, Class intendedClass) { if(obj != null && intendedClass == null) { intendedClass = obj.getClass(); } if(intendedClass != null) { intendedClass = Java.maybeBoxClass(intendedClass); if(!intendedClass.isInstance(obj)) { throw new ClassCastException(obj + " can not be cast to " + intendedClass); } } this.obj = obj; this.intendedClass = intendedClass; } @Override public LispObject typeOf() { return Symbol.JAVA_OBJECT; } @Override public LispObject classOf() { if(obj == null) { return BuiltInClass.JAVA_OBJECT; } else { return ENSURE_JAVA_CLASS.execute(new JavaObject(obj.getClass())); } } @Override public LispObject typep(LispObject type) { if (type == Symbol.JAVA_OBJECT) return T; if (type == BuiltInClass.JAVA_OBJECT) return T; LispObject cls = NIL; if(type instanceof Symbol) { cls = LispClass.findClass(type, false); } if(cls == NIL) { cls = type; } if(cls.typep(LispClass.findClass(JAVA_CLASS, false)) != NIL) { if(obj != null) { Class c = (Class) JAVA_CLASS_JCLASS.execute(cls).javaInstance(); return c.isAssignableFrom(obj.getClass()) ? T : NIL; } else { return T; } } else if(cls == BuiltInClass.SEQUENCE) { //This information is replicated here from java.lisp; it is a very //specific case, not worth implementing CPL traversal in typep if(java.util.List.class.isInstance(obj) || java.util.Set.class.isInstance(obj)) { return T; } } return super.typep(type); } @Override public LispObject STRING() { return new SimpleString(obj != null? obj.toString(): "null"); } public final Object getObject() { return obj; } /** Encapsulates obj, if required. * If obj is a {@link LispObject}, it's returned as-is. * * @param obj Any java object * @return obj or a new JavaObject encapsulating obj */ public final static LispObject getInstance(Object obj) { if (obj == null) return new JavaObject(null); if (obj instanceof LispObject) return (LispObject)obj; return new JavaObject(obj); } /** Encapsulates obj, if required. * If obj is a {@link LispObject}, it's returned as-is. * If not, a java object with the specified intended class is returned. * * @param obj Any java object * @param intendedClass the class that shall be used to access obj * @return obj or a new JavaObject encapsulating obj */ public final static LispObject getInstance(Object obj, Class intendedClass) { if (obj == null) return new JavaObject(null); if (obj instanceof LispObject) return (LispObject)obj; return new JavaObject(obj, intendedClass); } /** Encapsulates obj, if required. * If obj is a {@link LispObject}, it's returned as-is. * If obj is of a type which can be mapped to a lisp type, * an object of the mapped type is returned, if translated is true. * * @param obj * @param translated * @return a LispObject representing or encapsulating obj */ public final static LispObject getInstance(Object obj, boolean translated) { return getInstance(obj, translated, obj != null ? obj.getClass() : null); } /** Encapsulates obj, if required. * If obj is a {@link LispObject}, it's returned as-is. * If obj is of a type which can be mapped to a lisp type, * an object of the mapped type is returned, if translated is true. * * @param obj * @param translated * @param intendedClass the class that shall be used to reflectively * access obj; it is an error for obj not to be * an instance of this class. This parameter is ignored * if translated == true and the object can be * converted to a Lisp object. * @return a LispObject representing or encapsulating obj */ public final static LispObject getInstance(Object obj, boolean translated, Class intendedClass) { if (! translated) return getInstance(obj, intendedClass); if (obj == null) return NIL; if (obj instanceof LispObject) return (LispObject)obj; if (obj instanceof String) return new SimpleString((String)obj); if (obj instanceof Number) { // Number types ordered according to decreasing // estimated chances of occurrance if (obj instanceof Integer) return Fixnum.getInstance(((Integer)obj).intValue()); if (obj instanceof Float) return new SingleFloat((Float)obj); if (obj instanceof Double) return new DoubleFloat((Double)obj); if (obj instanceof Long) return LispInteger.getInstance(((Long)obj).longValue()); if (obj instanceof BigInteger) return Bignum.getInstance((BigInteger)obj); if (obj instanceof Short) return Fixnum.getInstance(((Short)obj).shortValue()); if (obj instanceof Byte) return Fixnum.getInstance(((Byte)obj).byteValue()); // We don't handle BigDecimal: it doesn't map to a Lisp type } if (obj instanceof Boolean) return ((Boolean)obj).booleanValue() ? T : NIL; if (obj instanceof Character) return LispCharacter.getInstance((Character)obj); if (obj instanceof Object[]) { Object[] array = (Object[]) obj; SimpleVector v = new SimpleVector(array.length); for (int i = array.length; i-- > 0;) v.aset(i, JavaObject.getInstance(array[i], translated)); return v; } // TODO // We might want to handle: // - streams // - others? return new JavaObject(obj, intendedClass); } @Override public Object javaInstance() { return obj; } @Override public Object javaInstance(Class c) { if(obj == null) { if(c.isPrimitive()) { throw new NullPointerException("Cannot assign null to " + c); } return obj; } else { c = Java.maybeBoxClass(c); if (c.isAssignableFrom(intendedClass) || c.isInstance(obj)) { // XXX In the case that c.isInstance(obj) should we then // "fix" the intendedClass field with the (presumably) // narrower type of 'obj'? // ME 20100323: I decided not to because a) we don't // know the "proper" class to narrow to (i.e. maybe // there's something "narrower" and b) I'm not sure how // primitive types relate to their boxed // representations. return obj; } else { return error(new TypeError(intendedClass.getName() + " is not assignable to " + c.getName())); } } } /** Returns the encapsulated Java object for * interoperability with wait, notify, synchronized, etc. * * @return The encapsulated object */ @Override public Object lockableInstance() { return obj; } public Class getIntendedClass() { return intendedClass; } public static final Object getObject(LispObject o) { if (o instanceof JavaObject) return ((JavaObject)o).obj; return // Not reached. type_error(o, Symbol.JAVA_OBJECT); } @Override public final boolean equal(LispObject other) { if (this == other) return true; if (other instanceof JavaObject) return (obj == ((JavaObject)other).obj); return false; } @Override public final boolean equalp(LispObject other) { return equal(other); } @Override public int sxhash() { return obj == null ? 0 : (obj.hashCode() & 0x7ffffff); } @Override public String writeToString() { if (obj instanceof ControlTransfer) return obj.toString(); final String s; if(obj != null) { Class c = obj.getClass(); StringBuilder sb = new StringBuilder(c.isArray() ? "jarray" : c.getName()); sb.append(' '); String ts = obj.toString(); if(ts.length() > 32) { //random value, should be chosen sensibly sb.append(ts.substring(0, 32) + "..."); } else { sb.append(ts); } s = sb.toString(); } else { s = "null"; } return unreadableString(s); } @Override public LispObject getDescription() { return new SimpleString(describeJavaObject(this)); } @Override public LispObject getParts() { if(obj != null) { LispObject parts = NIL; parts = parts.push(new Cons("Java class", new JavaObject(obj.getClass()))); if (intendedClass != null) { parts = parts.push(new Cons("intendedClass", new SimpleString(intendedClass.getCanonicalName()))); } if (obj.getClass().isArray()) { int length = Array.getLength(obj); for (int i = 0; i < length; i++) { parts = parts .push(new Cons(new SimpleString(i), JavaObject.getInstance(Array.get(obj, i)))); } } else { parts = Symbol.NCONC.execute(parts, getInspectedFields()); } return parts.nreverse(); } else { return NIL; } } private LispObject getInspectedFields() { final LispObject[] acc = new LispObject[] { NIL }; doClassHierarchy(obj.getClass(), new Function() { @Override public LispObject execute(LispObject arg) { //No possibility of type error - we're mapping this function //over a list of classes Class c = (Class) arg.javaInstance(); for(Field f : c.getDeclaredFields()) { LispObject value = NIL; try { if(!f.isAccessible()) { f.setAccessible(true); } value = JavaObject.getInstance(f.get(obj)); } catch(Exception e) {} acc[0] = acc[0].push(new Cons(f.getName(), value)); } return acc[0]; } }); return acc[0].nreverse(); } /** * Executes a function repeatedly over the minimal subtree of the * Java class hierarchy which contains every class in . */ private static void doClassHierarchy(Collection> classes, LispObject callback, Set> visited) { Collection> newClasses = new LinkedList>(); for(Class clss : classes) { if(clss == null) { continue; } if(!visited.contains(clss)) { callback.execute(JavaObject.getInstance(clss, true)); visited.add(clss); } if(!visited.contains(clss.getSuperclass())) { newClasses.add(clss.getSuperclass()); } for(Class iface : clss.getInterfaces()) { if (!visited.contains(iface)) { newClasses.add(iface); } } } if(!newClasses.isEmpty()) { doClassHierarchy(newClasses, callback, visited); } } /** * Executes a function recursively over and its superclasses and * interfaces. */ public static void doClassHierarchy(Class clss, LispObject callback) { if (clss != null) { Set> visited = new HashSet>(); Collection> classes = new ArrayList>(1); classes.add(clss); doClassHierarchy(classes, callback, visited); } } public static LispObject mapcarClassHierarchy(Class clss, final LispObject fn) { final LispObject[] acc = new LispObject[] { NIL }; doClassHierarchy(clss, new Function() { @Override public LispObject execute(LispObject arg) { acc[0] = acc[0].push(fn.execute(arg)); return acc[0]; } }); return acc[0].nreverse(); } public static String describeJavaObject(final JavaObject javaObject) { final Object obj = javaObject.getObject(); final StringBuilder sb = new StringBuilder(javaObject.writeToString()); sb.append(" is an object of type "); sb.append(Symbol.JAVA_OBJECT.writeToString()); sb.append("."); sb.append(System.getProperty("line.separator")); sb.append("The wrapped Java object is "); if (obj == null) { sb.append("null."); } else { sb.append("an "); final Class c = obj.getClass(); String className = c.getName(); if (c.isArray()) { sb.append("array of "); if (className.startsWith("[L") && className.endsWith(";")) { className = className.substring(1, className.length() - 1); sb.append(className); sb.append(" objects"); } else if (className.startsWith("[") && className.length() > 1) { char descriptor = className.charAt(1); final String type; switch (descriptor) { case 'B': type = "bytes"; break; case 'C': type = "chars"; break; case 'D': type = "doubles"; break; case 'F': type = "floats"; break; case 'I': type = "ints"; break; case 'J': type = "longs"; break; case 'S': type = "shorts"; break; case 'Z': type = "booleans"; break; default: type = "unknown type"; } sb.append(type); } sb.append(" with "); final int length = java.lang.reflect.Array.getLength(obj); sb.append(length); sb.append(" element"); if (length != 1) sb.append('s'); sb.append('.'); } else { sb.append("instance of "); sb.append(className); sb.append(':'); sb.append(System.getProperty("line.separator")); sb.append(" \""); sb.append(obj.toString()); sb.append('"'); } } return sb.toString(); } // ### describe-java-object private static final Primitive DESCRIBE_JAVA_OBJECT = new Primitive("describe-java-object", PACKAGE_JAVA, true) { @Override public LispObject execute(LispObject first, LispObject second) { if (!(first instanceof JavaObject)) return type_error(first, Symbol.JAVA_OBJECT); final Stream stream = checkStream(second); final JavaObject javaObject = (JavaObject) first; stream._writeString(describeJavaObject(javaObject)); return LispThread.currentThread().nothing(); } }; //JAVA-CLASS support //There is no point for this Map to be weak since values keep a reference to the corresponding //key (the Java class). This should not be a problem since Java classes are limited in number - //if they grew indefinitely, the JVM itself would crash. private static final Map, LispObject> javaClassMap = new HashMap, LispObject>(); public static LispObject registerJavaClass(Class javaClass, LispObject classMetaObject) { synchronized (javaClassMap) { javaClassMap.put(javaClass, classMetaObject); return classMetaObject; } } public static LispObject findJavaClass(Class javaClass) { synchronized (javaClassMap) { LispObject c = javaClassMap.get(javaClass); if (c != null) { return c; } else { return NIL; } } } private static final Primitive _FIND_JAVA_CLASS = new Primitive("%find-java-class", PACKAGE_JAVA, false, "class-name-or-class") { public LispObject execute(LispObject arg) { try { if(arg instanceof AbstractString) { return findJavaClass(Class.forName((String) arg.getStringValue())); } else { return findJavaClass((Class) arg.javaInstance()); } } catch (ClassNotFoundException e) { return error(new LispError("Cannot find Java class " + arg.getStringValue())); } } }; private static final Primitive _REGISTER_JAVA_CLASS = new Primitive("%register-java-class", PACKAGE_JAVA, false, "jclass class-metaobject") { public LispObject execute(LispObject jclass, LispObject classMetaObject) { return registerJavaClass((Class) jclass.javaInstance(), classMetaObject); } }; }