devmidletsuiteimpl.java

有关j2me的很好的例子可以研究一下

/**
 *
 * @(#)DevMIDletSuiteImpl.java	1.13 01/08/29
 *
 * Copyright 2001 by Sun Microsystems, Inc.,
 * 901 San Antonio Road, Palo Alto, California, 94303, U.S.A.
 * All rights reserved.
 */

package com.sun.midp.dev;

import java.io.*;

import javax.microedition.io.Connector;

import com.sun.midp.security.SecurityDomain;
import com.sun.midp.security.Actions;

import com.sun.midp.midlet.MIDletSuite;
import com.sun.midp.midlet.Scheduler;
import com.sun.midp.midlet.MIDletInfo;

import com.sun.midp.io.j2me.storage.RandomAccessStream;
import com.sun.midp.io.j2me.storage.File;

import com.sun.midp.midletsuite.JadProperties;
import com.sun.midp.midletsuite.ManifestProperties;
import com.sun.midp.midletsuite.MIDletSuiteImpl;
import com.sun.midp.midletsuite.InvalidJadException;

/**
 * Implements a the required MIDletSuite functionality needed by the
 * Scheduler. The class is only need for development environments.
 */
public class DevMIDletSuiteImpl extends MIDletSuiteImpl {
    /** Buffered properties from the application descriptor */
    private JadProperties bufferedJadProps = null;

    /** Initial midlet class name. */
    private String initialMIDletClassName = null;

    /** Storage path for this MIDlet suite */
    private String storageRoot = null;

    /**
     * number of midlets in this suite. less than 0 mean they need to
     * counted
     */
    private int numberOfMidlets = -1;

    /**
     * Constructs MIDletSuiteImpl from a raw JAD.
     * Assumes the suite is super trusted.
     *
     * @param jadFilename filename of the descriptor for the suite
     * @param midletClassName class name of the MIDlet to run when this
     *                        suite is scheduled
     * @param storageName name to separate this suite's storage from others
     * @exception IOException is thrown if any error prevents the installation
     *   of the MIDlet suite
     * @exception InvalidJadException if the downloaded application descriptor
     *   is invalid
     */
    public DevMIDletSuiteImpl(String jadFilename, String midletClassName,
                              String storageName) throws IOException,
            InvalidJadException {
        initialize(jadFilename, midletClassName, storageName);

        // without a jad we must assume at least one MIDlet
        if (jadFilename == null) {
            numberOfMidlets = 1;
        }
    }

    /**
     * Constructs MIDletSuiteImpl from a raw JAD.
     * Assumes the suite is super trusted.
     *
     * @param jadFilename filename of the descriptor for the suite
     * @param midletClassName class name of the MIDlet to run when this
     *                        suite is scheduled
     * @exception IOException is thrown if any error prevents the installation
     *   of the MIDlet suite
     * @exception InvalidJadException if the downloaded application descriptor
     *   is invalid
     */
    public DevMIDletSuiteImpl(String jadFilename, String midletClassName)
            throws IOException, InvalidJadException {
        initialize(jadFilename, midletClassName, "run_by_class_storage_");
    }

    /**
     * Initialize the MIDletSuite.
     * Assumes the suite is super trusted.
     *
     * @param jadFilename filename of the descriptor for the suite
     * @param midletClassName class name of the MIDlet to run when this
     *                        suite is scheduled
     * @param storageName name to separate this suite's storage from others
     */
    private void initialize(String jadFilename, String midletClassName,
                       String storageName) throws IOException,
            InvalidJadException {

        MIDletSuite midletSuite;
        RandomAccessStream storage;
        InputStream jadStream;

        midletSuite = Scheduler.getScheduler().getMIDletSuite();

        // if a MIDlet suite is not scheduled, assume the JAM is calling.
        if (midletSuite != null) {
            midletSuite.checkIfPermitted(Actions.DEVICE_CORE_FUNCTION);
        }

        if (jadFilename != null) {
            storage = new RandomAccessStream();
            storage.connect(jadFilename, Connector.READ);
            try {
                jadStream = storage.openInputStream();
                bufferedJadProps = new JadProperties();
                bufferedJadProps.load(jadStream);
            } finally {
                storage.disconnect();
            }
        }

        storageRoot = File.getStorageRoot() + storageName;

        initialMIDletClassName = midletClassName;

        numberOfMidlets = countMIDlets();
    }

    /**
     * Get a property of the suite. A property is an attribute from
     * the application descriptor.
     *
     * @param key the name of the property
     * @return A string with the value of the property.
     * 		<code>null</code> is returned if no value is available for
     *          the key.
     */
    public String getProperty(String key) {
        String prop;

        if (bufferedJadProps == null) {
            return null;
        }

        return bufferedJadProps.getProperty(key);
    }

    /**
     * Provides the number of of MIDlets in this suite.
     *
     * @return number of MIDlet in the suite
     */
    public int getNumberOfMIDlets() {
        return numberOfMidlets;
    }

    /**
     * Loads the initial midlet to run.
     *
     * @exception ClassNotFoundException if one of the MIDlet classes cannot
     * be found
     * @exception InstantiationException if an instance cannot be created
     * @exception IllegalAccessException if an instance cannot be accessed
     */  
    public void loadInitialMIDlet() throws
            ClassNotFoundException, InstantiationException,
            IllegalAccessException {
        loadInitialMIDlet(initialMIDletClassName, false);
    }

    /**
     * Gets the name of the security domain for the suite.
     * This method will always return "untrusted".
     *
     * @return name of security domain
     */
    public String getSecurityDomainName() {
        return "untrusted";
    }

    /**
     * Check to see the domain permitted to perform a specific action.
     * This method will always throw a security exception.
     *
     * @param action an action code from com.sun.midp.security.Action
     * @exception SecurityException if the domain is not
     *            permitted to perform the specified action.
     */
    public void checkIfPermitted(int action) {
        throw new SecurityException();
    }

    /**
     * Schedules this MIDlet suite to run.
     * Returns after the last midlet has been destroyed.
     * @exception ClassNotFoundException if one of the MIDlet classes cannot
     * be found.
     * @exception InstantiationException if an instance can not be created.
     */
    public void schedule() throws
            ClassNotFoundException, InstantiationException,
            IllegalAccessException {
        // assume the default scheduler
        Scheduler.getScheduler().schedule(this);
    }

    /**
     * Gets the path root of any file this suite.
     * Has any needed file separators appended.
     *
     * @return storage path root
     */
    public String getStorageRoot() {
        return storageRoot;
    }

    /**
     * Get a named resource out of the JAR of this MIDlet suite.
     *
     * @param name name of the resource
     * @return raw bytes of the resource or null if not available
     */
    public byte[] getResource(String name) {
        return null;
    }

    /**
     * Get the amount of storage on the device that this suite is using.
     * This includes the JAD, JAR, management data, and RMS.
     *
     * @return number of bytes of storage the suite is using.
     */
    public int getStorageUsed() {
        return 0;
    }

    /**
     * The URL that the JAD of the suite was downloaded from.
     *
     * @return URL of the JAD, never null, even in development environments
     */
    public String getJadUrl() {
        return "None";
    }
}