org.jboss.marshalling.reflect.SerializableField Maven / Gradle / Ivy
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* Copyright 2008, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.marshalling.reflect;
import java.lang.ref.WeakReference;
import java.lang.reflect.Field;
import java.util.concurrent.atomic.AtomicReference;
import java.security.AccessController;
import java.security.PrivilegedAction;
import org.jboss.marshalling.util.Kind;
/**
* Reflection information about a field on a serializable class.
*/
public final class SerializableField {
// the class that the field is attached to
private final WeakReference> classRef;
// the type of the field itself
private final WeakReference> typeRef;
private final AtomicReference> fieldRefRef = new AtomicReference>();
private final String name;
private final boolean unshared;
private final Kind kind;
private volatile boolean missing;
SerializableField(Class clazz, Class type, String name, boolean unshared) {
classRef = new WeakReference>(clazz);
typeRef = new WeakReference>(type);
this.name = name;
this.unshared = unshared;
// todo - see if a small Map is faster
if (type == boolean.class) {
kind = Kind.BOOLEAN;
} else if (type == byte.class) {
kind = Kind.BYTE;
} else if (type == short.class) {
kind = Kind.SHORT;
} else if (type == int.class) {
kind = Kind.INT;
} else if (type == long.class) {
kind = Kind.LONG;
} else if (type == char.class) {
kind = Kind.CHAR;
} else if (type == float.class) {
kind = Kind.FLOAT;
} else if (type == double.class) {
kind = Kind.DOUBLE;
} else {
kind = Kind.OBJECT;
}
}
private Field lookupField() {
if (missing) {
return null;
}
final Class clazz = classRef.get();
if (clazz != null) {
return AccessController.doPrivileged(new PrivilegedAction() {
public Field run() {
try {
return clazz.getDeclaredField(name);
} catch (NoSuchFieldException e) {
missing = true;
return null;
}
}
});
} else {
throw new IllegalStateException("Class unloaded");
}
}
/**
* Get the reflection {@code Field} for this serializable field. The resultant field will be accessable.
*
* @return the reflection field
*/
public Field getField() {
final WeakReference fieldRef = fieldRefRef.get();
if (fieldRef == null) {
final Field field = lookupField();
if (field != null) {
fieldRefRef.compareAndSet(null, new WeakReference(field));
}
AccessController.doPrivileged(new PrivilegedAction() {
public Void run() {
field.setAccessible(true);
return null;
}
});
return field;
} else {
final Field field = fieldRef.get();
if (field != null) {
return field;
}
return AccessController.doPrivileged(new PrivilegedAction() {
public Field run() {
final Field newField = lookupField();
final WeakReference newFieldRef;
if (newField == null) {
newFieldRef = null;
} else {
newField.setAccessible(true);
newFieldRef = new WeakReference(newField);
}
fieldRefRef.compareAndSet(fieldRef, newFieldRef);
return newField;
}
});
}
}
/**
* Get the name of the field.
*
* @return the name
*/
public String getName() {
return name;
}
/**
* Determine whether this field is marked as "unshared".
*
* @return {@code true} if the field is unshared
*/
public boolean isUnshared() {
return unshared;
}
/**
* Get the kind of field.
*
* @return the kind
*/
public Kind getKind() {
return kind;
}
/**
* Get the field type.
*
* @return the field type
*/
public Class getType() throws ClassNotFoundException {
return SerializableClass.dereference(typeRef);
}
}