publickeystorebuilderbase.java

有关j2me的很好的例子可以研究一下

/*
 *  @(#)PublicKeyStoreBuilderBase.java	1.2 01/08/08
 * 
 *  Copyright (c) 2001 Sun Microsystems, Inc., 901 San Antonio Road,
 *  Palo Alto, CA 94303, U.S.A.  All Rights Reserved.
 *
 *  Sun Microsystems, Inc. has intellectual property rights relating
 *  to the technology embodied in this software.  In particular, and
 *  without limitation, these intellectual property rights may include
 *  one or more U.S. patents, foreign patents, or pending
 *  applications.  Sun, Sun Microsystems, the Sun logo, Java, KJava,
 *  and all Sun-based and Java-based marks are trademarks or
 *  registered trademarks of Sun Microsystems, Inc.  in the United
 *  States and other countries.
 *
 *  This software is distributed under licenses restricting its use,
 *  copying, distribution, and decompilation.  No part of this
 *  software may be reproduced in any form by any means without prior
 *  written authorization of Sun and its licensors, if any.
 *
 *  FEDERAL ACQUISITIONS:  Commercial Software -- Government Users
 *  Subject to Standard License Terms and Conditions
 */
package com.sun.midp.publickeystore;

import java.io.*;
import java.util.*;

/**
 * A read-write serializable {@link PublicKeyStore}. This class is the base
 * for {@link PublicKeyStoreBuilder}, and does not have any methods that
 * depend on any Microediton specific classes so it can be used alone in a
 * tool written with Standard Edition Java.
 */
public class PublicKeyStoreBuilderBase extends PublicKeyStore {
    /** Vecor of keys maintained as a list. */
    private Vector keyList = new Vector();

    /**
     * Constructs an empty read-write keystore.
     */
    public PublicKeyStoreBuilderBase() {
        initPublicKeyStore(keyList);
    };

    /**
     * Constructs a read-write keystore from a serialized keystore created
     * by this class.
     * @param in stream to read a keystore serialized by
     *        {@link #serialize(OutputStream)} from
     * @exception IOException if the key storage was corrupted
     */
    public PublicKeyStoreBuilderBase(InputStream in) throws IOException {
        initPublicKeyStore(in, keyList);
    }

    /**
     * Serializes the keystore to the given stream.
     * @param out stream to serialize the keystore to
     * @exception IOException is thrown, if an I/O error occurs
     */
    public void serialize(OutputStream out) throws IOException {
        OutputStorage storage = new OutputStorage(out);
        Enumeration e;
        PublicKeyInfo keyInfo;
  
        e = keyList.elements();
        while (e.hasMoreElements()) {
            keyInfo = (PublicKeyInfo)e.nextElement();
            keyInfo.putKeyInStorage(storage);
        }
    }

    /**
     * Adds a public key.
     * @param keyInfo the key to add
     * @return true if successful, or false if a key for the owner is
     *         already in the store
     */
    public synchronized boolean addKey(PublicKeyInfo keyInfo) {
        if (keyInfo == null) {
            return false;
        }

        // do not allow duplicates of owners.
        if (findKey(keyInfo.getOwner()) != null) {
            return false;
        }

        keyList.addElement(keyInfo);
        return true;
    }

    /**
     * Updates all of an key's information except for the security domain.
     * information in the certificate.
     * @param owner distinguished name of the key's owner
     * @param newKeyInfo new key information
     * @return true if successful, or false if not
     */
    public synchronized boolean updateKey(String owner,
                                          PublicKeyInfo newKeyInfo) {
        PublicKeyInfo oldKeyInfo;
        int index;

        oldKeyInfo = findKey(owner);
        if (oldKeyInfo == null) {
            return false;
        }

        index = keyList.indexOf(oldKeyInfo);

        newKeyInfo.setDomain(oldKeyInfo.getDomain());

        keyList.setElementAt(newKeyInfo, index);

        return true;
    }

    /**
     * Deletes a public key from this keystore.
     * @param owner distinguished name of the key's owner
     * @return true if successful, or false if not
     */
    public boolean deleteKey(String owner) {
        PublicKeyInfo keyInfo;

        keyInfo = findKey(owner);
        if (keyInfo == null) {
            return false;
        }

        keyList.removeElement(keyInfo);

        return true;
    }
}