jdk/src/share/classes/javax/smartcardio/CardTerminals.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/smartcardio/CardTerminals.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,219 @@
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.smartcardio;
+
+import java.util.*;
+
+/**
+ * The set of terminals supported by a TerminalFactory.
+ * This class allows applications to enumerate the available CardTerminals,
+ * obtain a specific CardTerminal, or wait for the insertion or removal of
+ * cards.
+ *
+ * <p>This class is multi-threading safe and can be used by multiple
+ * threads concurrently. However, this object keeps track of the card
+ * presence state of each of its terminals. Multiple objects should be used
+ * if independent calls to {@linkplain #waitForChange} are required.
+ *
+ * <p>Applications can obtain instances of this class by calling
+ * {@linkplain TerminalFactory#terminals}.
+ *
+ * @see TerminalFactory
+ * @see CardTerminal
+ *
+ * @since   1.6
+ * @author  Andreas Sterbenz
+ * @author  JSR 268 Expert Group
+ */
+public abstract class CardTerminals {
+
+    /**
+     * Constructs a new CardTerminals object.
+     *
+     * <p>This constructor is called by subclasses only. Application should
+     * call {@linkplain TerminalFactory#terminals}
+     * to obtain a CardTerminals object.
+     */
+    protected CardTerminals() {
+        // empty
+    }
+
+    /**
+     * Returns an unmodifiable list of all available terminals.
+     *
+     * @return an unmodifiable list of all available terminals.
+     *
+     * @throws CardException if the card operation failed
+     */
+    public List<CardTerminal> list() throws CardException {
+         return list(State.ALL);
+    }
+
+    /**
+     * Returns an unmodifiable list of all terminals matching the specified
+     * state.
+     *
+     * <p>If state is {@link State#ALL State.ALL}, this method returns
+     * all CardTerminals encapsulated by this object.
+     * If state is {@link State#CARD_PRESENT State.CARD_PRESENT} or
+     * {@link State#CARD_ABSENT State.CARD_ABSENT}, it returns all
+     * CardTerminals where a card is currently present or absent, respectively.
+     *
+     * <p>If state is {@link State#CARD_INSERTION State.CARD_INSERTION} or
+     * {@link State#CARD_REMOVAL State.CARD_REMOVAL}, it returns all
+     * CardTerminals for which an insertion (or removal, respectively)
+     * was detected during the last call to {@linkplain #waitForChange}.
+     * If <code>waitForChange()</code> has not been called on this object,
+     * <code>CARD_INSERTION</code> is equivalent to <code>CARD_PRESENT</code>
+     * and <code>CARD_REMOVAL</code> is equivalent to <code>CARD_ABSENT</code>.
+     * For an example of the use of <code>CARD_INSERTION</code>,
+     * see {@link #waitForChange}.
+     *
+     * @param state the State
+     * @return an unmodifiable list of all terminals matching the specified
+     *   attribute.
+     *
+     * @throws NullPointerException if attr is null
+     * @throws CardException if the card operation failed
+     */
+    public abstract List<CardTerminal> list(State state) throws CardException;
+
+    /**
+     * Returns the terminal with the specified name or null if no such
+     * terminal exists.
+     *
+     * @return the terminal with the specified name or null if no such
+     * terminal exists.
+     *
+     * @throws NullPointerException if name is null
+     */
+    public CardTerminal getTerminal(String name) {
+        if (name == null) {
+            throw new NullPointerException();
+        }
+        try {
+            for (CardTerminal terminal : list()) {
+                if (terminal.getName().equals(name)) {
+                    return terminal;
+                }
+            }
+            return null;
+        } catch (CardException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Waits for card insertion or removal in any of the terminals of this
+     * object.
+     *
+     * <p>This call is equivalent to calling
+     * {@linkplain #waitForChange(long) waitForChange(0)}.
+     *
+     * @throws IllegalStateException if this <code>CardTerminals</code>
+     *   object does not contain any terminals
+     * @throws CardException if the card operation failed
+     */
+    public void waitForChange() throws CardException {
+        waitForChange(0);
+    }
+
+    /**
+     * Waits for card insertion or removal in any of the terminals of this
+     * object or until the timeout expires.
+     *
+     * <p>This method examines each CardTerminal of this object.
+     * If a card was inserted into or removed from a CardTerminal since the
+     * previous call to <code>waitForChange()</code>, it returns
+     * immediately.
+     * Otherwise, or if this is the first call to <code>waitForChange()</code>
+     * on this object, it blocks until a card is inserted into or removed from
+     * a CardTerminal.
+     *
+     * <p>If <code>timeout</code> is greater than 0, the method returns after
+     * <code>timeout</code> milliseconds even if there is no change in state.
+     * In that case, this method returns <code>false</code>; otherwise it
+     * returns <code>true</code>.
+     *
+     * <p>This method is often used in a loop in combination with
+     * {@link #list(CardTerminals.State) list(State.CARD_INSERTION)},
+     * for example:
+     * <pre>
+     *  TerminalFactory factory = ...;
+     *  CardTerminals terminals = factory.terminals();
+     *  while (true) {
+     *      for (CardTerminal terminal : terminals.list(CARD_INSERTION)) {
+     *          // examine Card in terminal, return if it matches
+     *      }
+     *      terminals.waitForChange();
+     *  }</pre>
+     *
+     * @param timeout if positive, block for up to <code>timeout</code>
+     *   milliseconds; if zero, block indefinitely; must not be negative
+     * @return false if the method returns due to an expired timeout,
+     *   true otherwise.
+     *
+     * @throws IllegalStateException if this <code>CardTerminals</code>
+     *   object does not contain any terminals
+     * @throws IllegalArgumentException if timeout is negative
+     * @throws CardException if the card operation failed
+     */
+    public abstract boolean waitForChange(long timeout) throws CardException;
+
+    /**
+     * Enumeration of attributes of a CardTerminal.
+     * It is used as a parameter to the {@linkplain CardTerminals#list} method.
+     *
+     * @since 1.6
+     */
+    public static enum State {
+        /**
+         * All CardTerminals.
+         */
+        ALL,
+        /**
+         * CardTerminals in which a card is present.
+         */
+        CARD_PRESENT,
+        /**
+         * CardTerminals in which a card is not present.
+         */
+        CARD_ABSENT,
+        /**
+         * CardTerminals for which a card insertion was detected during the
+         * latest call to {@linkplain State#waitForChange waitForChange()}
+         * call.
+         */
+        CARD_INSERTION,
+        /**
+         * CardTerminals for which a card removal was detected during the
+         * latest call to {@linkplain State#waitForChange waitForChange()}
+         * call.
+         */
+        CARD_REMOVAL,
+    }
+
+}