| /* ObjectStreamField.java -- Class used to store name and class of fields |
| Copyright (C) 1998, 1999, 2003, 2004 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.io; |
| |
| import gnu.java.lang.reflect.TypeSignature; |
| |
| import java.lang.reflect.Field; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| |
| /** |
| * This class intends to describe the field of a class for the serialization |
| * subsystem. Serializable fields in a serializable class can be explicitly |
| * exported using an array of ObjectStreamFields. |
| */ |
| public class ObjectStreamField implements Comparable |
| { |
| private String name; |
| private Class type; |
| private String typename; |
| private int offset = -1; // XXX make sure this is correct |
| private boolean unshared; |
| private boolean persistent = false; |
| private boolean toset = true; |
| private Field field; |
| |
| ObjectStreamField (Field field) |
| { |
| this (field.getName(), field.getType()); |
| this.field = field; |
| } |
| |
| /** |
| * This constructor creates an ObjectStreamField instance |
| * which represents a field named <code>name</code> and is |
| * of the type <code>type</code>. |
| * |
| * @param name Name of the field to export. |
| * @param type Type of the field in the concerned class. |
| */ |
| public ObjectStreamField (String name, Class type) |
| { |
| this (name, type, false); |
| } |
| |
| /** |
| * This constructor creates an ObjectStreamField instance |
| * which represents a field named <code>name</code> and is |
| * of the type <code>type</code>. |
| * |
| * @param name Name of the field to export. |
| * @param type Type of the field in the concerned class. |
| * @param unshared true if field will be unshared, false otherwise. |
| */ |
| public ObjectStreamField (String name, Class type, boolean unshared) |
| { |
| if (name == null) |
| throw new NullPointerException(); |
| |
| this.name = name; |
| this.type = type; |
| this.typename = TypeSignature.getEncodingOfClass(type); |
| this.unshared = unshared; |
| } |
| |
| /** |
| * There are many cases you can not get java.lang.Class from typename |
| * if your context class loader cannot load it, then use typename to |
| * construct the field. |
| * |
| * @param name Name of the field to export. |
| * @param typename The coded name of the type for this field. |
| */ |
| ObjectStreamField (String name, String typename) |
| { |
| this.name = name; |
| this.typename = typename; |
| try |
| { |
| type = TypeSignature.getClassForEncoding(typename); |
| } |
| catch(ClassNotFoundException e) |
| { |
| } |
| } |
| |
| /** |
| * There are many cases you can not get java.lang.Class from typename |
| * if your context class loader cann not load it, then use typename to |
| * construct the field. |
| * |
| * @param name Name of the field to export. |
| * @param typename The coded name of the type for this field. |
| * @param loader The class loader to use to resolve class names. |
| */ |
| ObjectStreamField (String name, String typename, ClassLoader loader) |
| { |
| this.name = name; |
| this.typename = typename; |
| try |
| { |
| type = TypeSignature.getClassForEncoding(typename, true, loader); |
| } |
| catch(ClassNotFoundException e) |
| { |
| } |
| } |
| |
| /** |
| * This method returns the name of the field represented by the |
| * ObjectStreamField instance. |
| * |
| * @return A string containing the name of the field. |
| */ |
| public String getName () |
| { |
| return name; |
| } |
| |
| /** |
| * This method returns the class representing the type of the |
| * field which is represented by this instance of ObjectStreamField. |
| * |
| * @return A class representing the type of the field. |
| */ |
| public Class getType () |
| { |
| return type; |
| } |
| |
| /** |
| * This method returns the char encoded type of the field which |
| * is represented by this instance of ObjectStreamField. |
| * |
| * @return A char representing the type of the field. |
| */ |
| public char getTypeCode () |
| { |
| return typename.charAt (0); |
| } |
| |
| /** |
| * This method returns a more explicit type name than |
| * {@link #getTypeCode()} in the case the type is a real |
| * class (and not a primitive). |
| * |
| * @return The name of the type (class name) if it is not a |
| * primitive, in the other case null is returned. |
| */ |
| public String getTypeString () |
| { |
| // use intern() |
| if (isPrimitive()) |
| return null; |
| return typename.intern(); |
| } |
| |
| /** |
| * This method returns the current offset of the field in |
| * the serialization stream relatively to the other fields. |
| * The offset is expressed in bytes. |
| * |
| * @return The offset of the field in bytes. |
| * @see #setOffset(int) |
| */ |
| public int getOffset () |
| { |
| return offset; |
| } |
| |
| /** |
| * This method sets the current offset of the field. |
| * |
| * @param off The offset of the field in bytes. |
| * @see #getOffset() |
| */ |
| protected void setOffset (int off) |
| { |
| offset = off; |
| } |
| |
| /** |
| * This method returns whether the field represented by this object is |
| * unshared or not. |
| * |
| * @return Tells if this field is unshared or not. |
| */ |
| public boolean isUnshared () |
| { |
| return unshared; |
| } |
| |
| /** |
| * This method returns true if the type of the field |
| * represented by this instance is a primitive. |
| * |
| * @return true if the type is a primitive, false |
| * in the other case. |
| */ |
| public boolean isPrimitive () |
| { |
| return typename.length() == 1; |
| } |
| |
| /** |
| * Compares this object to the given object. |
| * |
| * @param obj the object to compare to. |
| * |
| * @return -1, 0 or 1. |
| */ |
| public int compareTo (Object obj) |
| { |
| ObjectStreamField f = (ObjectStreamField) obj; |
| boolean this_is_primitive = isPrimitive (); |
| boolean f_is_primitive = f.isPrimitive (); |
| |
| if (this_is_primitive && !f_is_primitive) |
| return -1; |
| |
| if (!this_is_primitive && f_is_primitive) |
| return 1; |
| |
| return getName ().compareTo (f.getName ()); |
| } |
| |
| /** |
| * This method is specific to classpath's implementation and so has the default |
| * access. It changes the state of this field to "persistent". It means that |
| * the field should not be changed when the stream is read (if it is not |
| * explicitly specified using serialPersistentFields). |
| * |
| * @param persistent True if the field is persistent, false in the |
| * other cases. |
| * @see #isPersistent() |
| */ |
| void setPersistent(boolean persistent) |
| { |
| this.persistent = persistent; |
| } |
| |
| /** |
| * This method returns true if the field is marked as persistent. |
| * |
| * @return True if persistent, false in the other cases. |
| * @see #setPersistent(boolean) |
| */ |
| boolean isPersistent() |
| { |
| return persistent; |
| } |
| |
| /** |
| * This method is specific to classpath's implementation and so |
| * has the default access. It changes the state of this field as |
| * to be set by ObjectInputStream. |
| * |
| * @param toset True if this field should be set, false in the other |
| * cases. |
| * @see #isToSet() |
| */ |
| void setToSet(boolean toset) |
| { |
| this.toset = toset; |
| } |
| |
| /** |
| * This method returns true if the field is marked as to be |
| * set. |
| * |
| * @return True if it is to be set, false in the other cases. |
| * @see #setToSet(boolean) |
| */ |
| boolean isToSet() |
| { |
| return toset; |
| } |
| |
| /** |
| * This method searches for its field reference in the specified class |
| * object. It requests privileges. If an error occurs the internal field |
| * reference is not modified. |
| * |
| * @throws NoSuchFieldException if the field name does not exist in this class. |
| * @throws SecurityException if there was an error requesting the privileges. |
| */ |
| void lookupField(Class clazz) throws NoSuchFieldException, SecurityException |
| { |
| final Field f = clazz.getDeclaredField(name); |
| |
| AccessController.doPrivileged(new PrivilegedAction() |
| { |
| public Object run() |
| { |
| f.setAccessible(true); |
| return null; |
| } |
| }); |
| |
| this.field = f; |
| } |
| |
| /** |
| * This method check whether the field described by this |
| * instance of ObjectStreamField is compatible with the |
| * actual implementation of this field. |
| * |
| * @throws NullPointerException if this field does not exist |
| * in the real class. |
| * @throws InvalidClassException if the types are incompatible. |
| */ |
| void checkFieldType() throws InvalidClassException |
| { |
| Class ftype = field.getType(); |
| |
| if (!ftype.isAssignableFrom(type)) |
| throw new InvalidClassException |
| ("invalid field type for " + name + |
| " in class " + field.getDeclaringClass()); |
| } |
| |
| /** |
| * Returns a string representing this object. |
| * |
| * @return the string. |
| */ |
| public String toString () |
| { |
| return "ObjectStreamField< " + type + " " + name + " >"; |
| } |
| |
| final void setBooleanField(Object obj, boolean val) |
| { |
| VMObjectStreamClass.setBooleanNative(field, obj, val); |
| } |
| |
| final void setByteField(Object obj, byte val) |
| { |
| VMObjectStreamClass.setByteNative(field, obj, val); |
| } |
| |
| final void setCharField(Object obj, char val) |
| { |
| VMObjectStreamClass.setCharNative(field, obj, val); |
| } |
| |
| final void setShortField(Object obj, short val) |
| { |
| VMObjectStreamClass.setShortNative(field, obj, val); |
| } |
| |
| final void setIntField(Object obj, int val) |
| { |
| VMObjectStreamClass.setIntNative(field, obj, val); |
| } |
| |
| final void setLongField(Object obj, long val) |
| { |
| VMObjectStreamClass.setLongNative(field, obj, val); |
| } |
| |
| final void setFloatField(Object obj, float val) |
| { |
| VMObjectStreamClass.setFloatNative(field, obj, val); |
| } |
| |
| final void setDoubleField(Object obj, double val) |
| { |
| VMObjectStreamClass.setDoubleNative(field, obj, val); |
| } |
| |
| final void setObjectField(Object obj, Object val) |
| { |
| VMObjectStreamClass.setObjectNative(field, obj, val); |
| } |
| } |