breakpoint.java

j2me的基于http协议的断点续传。支持多线程的断点续传。

package NetFox;

import javax.microedition.midlet.*;
import javax.microedition.io.*;
import javax.microedition.lcdui.*;
import LogUtils;

import java.io.*;

public class BreakPoint extends MIDlet {
    private FileSelector fileSelector;

    public BreakPoint() {
        fileSelector = new FileSelector(this);
    }

    /**
     * Start creates the thread to do the MessageConnection receive
     * text.
     * It should return immediately to keep the dispatcher
     * from hanging.
     */
    public void startApp() 
    {
        Displayable current = Display.getDisplay(this).getCurrent();
        LogUtils.setLevel(LogUtils.LEVEL_INFO);
        
        if (current == null) {
            if (0 != Utility.init()) {
                Alert splashScreen = new Alert(null, "init log error", null, null);
                Display.getDisplay(this).setCurrent(splashScreen);
            }
            Utility.log("startApp ... \n");
            
            // Checks whether the API is available
            boolean isAPIAvailable = System.getProperty(
                "microedition.io.file.FileConnection.version") != null;
            
            // shows splash screen
            String text = "File Conn test";
        
            if (!isAPIAvailable) {
                text += "\nFile Connection API is not available";
            }
        
            Alert splashScreen = new Alert(null, text, null, null);
            if (isAPIAvailable) {
                splashScreen.setTimeout(1000);
                Display.getDisplay(this).setCurrent(splashScreen, fileSelector);
            } else {
                Display.getDisplay(this).setCurrent(splashScreen);
            }
        } else {
            Display.getDisplay(this).setCurrent(current);
        }
    }

    /**
     * Pause signals the thread to stop by clearing the thread field.
     * If stopped before done with the iterations it will
     * be restarted from scratch later.
     */
    public void pauseApp() {
        Utility.log("pauseApp ... \n");
        Utility.close();
    }

    /**
     * Destroy must cleanup everything.  The thread is signaled
     * to stop and no result is produced.
     * @param unconditional true if a forced shutdown was requested
     */
    public void destroyApp(boolean unconditional) {
        Utility.log("destroyApp ... \n");
        Utility.close();
        notifyDestroyed();
    }

    void fileSelectorExit() {
       destroyApp(false);
    }
    
    /**
     * A method used to show errors.
     * @param e Exception
     */
    void showError(Exception e) {
       ErrorScreen.showError(e.getMessage(), fileSelector);
    }

    /**
     * A method used to show messages.
     * @param text String
     */
    void showMsg(String text) {
        Alert infoScreen = new Alert(null, text, null, null);
        infoScreen.setTimeout(3000);
        Display.getDisplay(this).setCurrent(infoScreen, fileSelector);
    }
}