SimulatorSystem.java

/*
 * Copyright 2011 Licel LLC.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.licel.jcardsim.base;

import javacard.framework.*;

import java.lang.reflect.Constructor;

/**
 * Base implementation of <code>JCSystem</code>.
 * @see JCSystem
 */
public class SimulatorSystem {
    /**
     * Response status : Applet creation failed = 0x6444
     */
    public static final short SW_APPLET_CREATION_FAILED = 0x6444;

    /**
     * Response status : Exception occurred = 0x6424
     */
    public static final short SW_EXCEPTION_OCCURRED = 0x6424;

    /** @deprecated Use <code>SW_APPLET_CREATION_FAILED</code> */
    public static final short SW_APPLET_CRATION_FAILED = SW_APPLET_CREATION_FAILED;

    /** @deprecated Use <code>SW_EXCEPTION_OCCURRED</code> */
    public static final short SW_EXCEPTION_OCCURED = SW_EXCEPTION_OCCURRED;


    /**
     * Holds the currently active instance
     */
    private static final ThreadLocal<SimulatorRuntime> currentRuntime = new ThreadLocal<SimulatorRuntime>();

    /**
     * the default instance. Used by <code>Simulator</code>
     */
    public static final SimulatorRuntime DEFAULT_RUNTIME;

    static {
        SimulatorRuntime sim;
        
        try {
            sim = setCurrentInstance((SimulatorRuntime)Class.forName("com.licel.globalplatform.GpSimulatorRuntime").newInstance());
        } catch (Throwable ex) {
            sim = setCurrentInstance(new SimulatorRuntime());
        }
        
        DEFAULT_RUNTIME = sim;
    }
    
    /**
     * Get the currently active SimulatorRuntime instance
     *
     * This method should be only called by JCE implementation classes like
     * <code>JCSystem</code>
     *
     * @return current instance
     */
    public static SimulatorRuntime instance() {
        SimulatorRuntime simulatorRuntime = currentRuntime.get();
        if (simulatorRuntime == null) {
            throw new AssertionError("No current simulator instance");
        }
        return simulatorRuntime;
    }

    /**
     * Internal method to set the currently active SimulatorRuntime
     * @param simulatorRuntime simulatorRuntime to set
     * @return <code>simulatorRuntime</code>
     */
    static SimulatorRuntime setCurrentInstance(SimulatorRuntime simulatorRuntime) {
        currentRuntime.set(simulatorRuntime);
        return simulatorRuntime;
    }
}