objectstreamfield.java

来自「JAVA 所有包」· Java 代码 · 共 256 行

/*
 * @(#)ObjectStreamField.java	1.25 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

/*
 * Licensed Materials - Property of IBM
 * RMI-IIOP v1.0
 * Copyright IBM Corp. 1998 1999  All Rights Reserved
 *
 * US Government Users Restricted Rights - Use, duplication or
 * disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
 */

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 ; 
}