| /* ArrayPersistenceDelegate.java - A PersistenceDelegate that handles arrays. |
| Copyright (C) 2005 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 gnu.java.beans.encoder; |
| |
| import java.beans.Encoder; |
| import java.beans.Expression; |
| import java.beans.PersistenceDelegate; |
| import java.beans.Statement; |
| |
| import java.lang.reflect.Array; |
| import java.util.HashMap; |
| |
| public class ArrayPersistenceDelegate extends PersistenceDelegate |
| { |
| private static final HashMap NULL_VALUES = new HashMap(); |
| |
| static |
| { |
| NULL_VALUES.put(Boolean.TYPE, Boolean.FALSE); |
| NULL_VALUES.put(Byte.TYPE, Byte.valueOf((byte) 0)); |
| NULL_VALUES.put(Short.TYPE, Short.valueOf((short) 0)); |
| NULL_VALUES.put(Integer.TYPE, Integer.valueOf(0)); |
| NULL_VALUES.put(Long.TYPE, Long.valueOf(0)); |
| NULL_VALUES.put(Float.TYPE, Float.valueOf(0.0f)); |
| NULL_VALUES.put(Double.TYPE, Double.valueOf(0.0)); |
| } |
| |
| protected Expression instantiate(Object oldInstance, Encoder out) |
| { |
| Class type = oldInstance.getClass().getComponentType(); |
| |
| // oldInstance is expected to be an array, then |
| // getClass().getComponentType() should lead |
| // to its component type. |
| assert (type != null); |
| |
| // Not handling primitive types in a special way here |
| // causes that Class.forName("int") is built as an Expression |
| // later which would cause an exception if executed. A special |
| // handling to avoid the execution for primitive types can be |
| // java.beans.Encoder.writeExpression() . |
| return new Expression( |
| oldInstance, |
| Array.class, |
| "newInstance", |
| new Object[] { |
| type, |
| new Integer(Array.getLength(oldInstance)) }); |
| } |
| |
| protected void initialize(Class type, Object oldInstance, Object newInstance, |
| Encoder out) |
| { |
| int length = Array.getLength(oldInstance); |
| |
| // Compares the array value against a prototypical |
| // null value of the array's component type in order to skip |
| // writing the default values of an array. |
| |
| // Note: I have no idea why the persistence delegate for arrays writes |
| // an Expression that reads the value and then writes a Statement that sets |
| // the value. However it turned out that object arrays work better with the |
| // get-Expression and primitive array work fine with the set-Statement. |
| |
| type = type.getComponentType(); |
| if (type.isPrimitive()) |
| { |
| Object nullValue = NULL_VALUES.get(type); |
| |
| for (int i = 0; i < length; i++) |
| { |
| Object oldValue = Array.get(oldInstance, i); |
| |
| if (!oldValue.equals(nullValue)) |
| { |
| out.writeExpression(new Expression(Array.class, "get", |
| new Object[] { oldInstance, |
| Integer.valueOf(i), |
| })); |
| |
| out.writeStatement(new Statement(Array.class, "set", |
| new Object[] { |
| oldInstance, |
| Integer.valueOf(i), |
| oldValue |
| })); |
| } |
| } |
| |
| } |
| else |
| { |
| |
| for (int i = 0; i < length; i++) |
| { |
| Object oldValue = Array.get(oldInstance, i); |
| |
| if (oldValue != null) |
| { |
| out.writeExpression(new Expression(Array.class, "get", |
| new Object[] { oldInstance, |
| Integer.valueOf(i), |
| })); |
| |
| out.writeStatement(new Statement(Array.class, "set", |
| new Object[] { |
| oldInstance, |
| Integer.valueOf(i), |
| oldValue |
| })); |
| } |
| } |
| } |
| |
| } |
| |
| } |