impl/io/ObjectStreamField.java

/*
 * Copyright (c) 1998, 2004, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * Licensed Materials - Property of IBM
 * RMI-IIOP v1.0
 * Copyright IBM Corp. 1998 1999  All Rights Reserved
 *
 */

package com.sun.corba.se.impl.io;

import java.lang.reflect.Field;
import java.lang.Comparable;
import java.util.Hashtable;

import sun.corba.Bridge ;
import java.security.AccessController ;
import java.security.PrivilegedAction ;

/**
 * A description of a field in a serializable class.
 * A array of these is used to declare the persistent fields of
 * a class.
 *
 */
public class ObjectStreamField implements Comparable
{
    private static final Bridge bridge =
        (Bridge)AccessController.doPrivileged(
            new PrivilegedAction() {
                public Object run() {
                    return Bridge.get() ;
                }
            }
        ) ;

    /**
     * Create a named field with the specified type.
     */
    ObjectStreamField(String n, Class clazz) {
        name = n;
        this.clazz = clazz;

        // Compute the typecode for easy switching
        if (clazz.isPrimitive()) {
            if (clazz == Integer.TYPE) {
                type = 'I';
            } else if (clazz == Byte.TYPE) {
                type = 'B';
            } else if (clazz == Long.TYPE) {
                type = 'J';
            } else if (clazz == Float.TYPE) {
                type = 'F';
            } else if (clazz == Double.TYPE) {
                type = 'D';
            } else if (clazz == Short.TYPE) {
                type = 'S';
            } else if (clazz == Character.TYPE) {
                type = 'C';
            } else if (clazz == Boolean.TYPE) {
                type = 'Z';
            }
        } else if (clazz.isArray()) {
            type = '[';
            typeString = ObjectStreamClass.getSignature(clazz);
        } else {
            type = 'L';
            typeString = ObjectStreamClass.getSignature(clazz);
        }

        if (typeString != null)
            signature = typeString;
        else
            signature = String.valueOf(type);

    }

    ObjectStreamField(Field field) {
        this(field.getName(), field.getType());
        setField( field ) ;
    }

    /**
     * Create an ObjectStreamField containing a reflected Field.
     */
    ObjectStreamField(String n, char t, Field f, String ts)
    {
        name = n;
        type = t;
        setField( f ) ;
        typeString = ts;

        if (typeString != null)
            signature = typeString;
        else
            signature = String.valueOf(type);

    }

    /**
     * Get the name of this field.
     */
    public String getName() {
        return name;
    }

    /**
     * Get the type of the field.
     */
    public Class getType() {
        if (clazz != null)
            return clazz;
        switch (type) {
        case 'B': clazz = Byte.TYPE;
            break;
        case 'C': clazz = Character.TYPE;
            break;
        case 'S': clazz = Short.TYPE;
            break;
        case 'I': clazz = Integer.TYPE;
            break;
        case 'J': clazz = Long.TYPE;
            break;
        case 'F': clazz = Float.TYPE;
            break;
        case 'D': clazz = Double.TYPE;
            break;
        case 'Z': clazz = Boolean.TYPE;
            break;
        case '[':
        case 'L':
            clazz = Object.class;
            break;
        }

        return clazz;
    }

    public char getTypeCode() {
        return type;
    }

    public String getTypeString() {
        return typeString;
    }

    Field getField() {
        return field;
    }

    void setField(Field field) {
        this.field = field;
        this.fieldID = bridge.objectFieldOffset( field ) ;
    }

    /*
     * Default constructor creates an empty field.
     * Usually used just to get to the sort functions.
     */
    ObjectStreamField() {
    }

    /**
     * test if this field is a primitive or not.
     */
    public boolean isPrimitive() {
        return (type != '[' && type != 'L');
    }

    /**
     * Compare this with another ObjectStreamField.
     * return -1 if this is smaller, 0 if equal, 1 if greater
     * types that are primitives are "smaller" than objects.
     * if equal, the names are compared.
     */
    public int compareTo(Object o) {
        ObjectStreamField f2 = (ObjectStreamField)o;
        boolean thisprim = (this.typeString == null);
        boolean otherprim = (f2.typeString == null);

        if (thisprim != otherprim) {
            return (thisprim ? -1 : 1);
        }
        return this.name.compareTo(f2.name);
    }

    /**
     * Compare the types of two class descriptors.
     * The match if they have the same primitive types.
     * or if they are both objects and the object types match.
     */
    public boolean typeEquals(ObjectStreamField other) {
        if (other == null || type != other.type)
            return false;

        /* Return true if the primitive types matched */
        if (typeString == null && other.typeString == null)
            return true;

        return ObjectStreamClass.compareClassNames(typeString,
                                                   other.typeString,
                                                   '/');
    }

    /* Returns the signature of the Field.
     *
     */
    public String getSignature() {

        return signature;

    }

    /**
     * Return a string describing this field.
     */
    public String toString() {
        if (typeString != null)
            return typeString + " " + name;
        else
            return type + " " + name;
    }

    public Class getClazz() {
        return clazz;
    }

    /* Returns the Field ID
     *
     */
    public long getFieldID() {
        return fieldID ;
    }

    private String name;                // the name of the field
    private char type;                  // type first byte of the type signature
    private Field field;                // Reflected field
    private String typeString;          // iff object, typename
    private Class clazz;                // the type of this field, if has been resolved

    // the next 2 things are RMI-IIOP specific, it can be easily
    // removed, if we can figure out all place where there are dependencies
    // to this.  Signature is esentially equal to typestring. Then
    // essentially we can use the java.io.ObjectStreamField as such.

    private String signature;   // the signature of the field
    private long fieldID = Bridge.INVALID_FIELD_OFFSET ;
}