filebrowserexample.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

/*
 * FileBrowserExample.java
 * 
 * Created on Aug 20, 2007, 10:22:30 AM
 * 
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package filebrowserexample;

import java.io.IOException;
import java.io.InputStream;
import javax.microedition.io.file.FileConnection;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import org.netbeans.microedition.lcdui.SplashScreen;
import org.netbeans.microedition.lcdui.pda.FileBrowser;

/**
 * @author devil
 */
public class FileBrowserExample extends MIDlet implements CommandListener {

    private boolean midletPaused = false;

    //<editor-fold defaultstate="collapsed" desc=" Generated Fields ">//GEN-BEGIN:|fields|0|
    private Command backCommand;
    private Command exitCommand;
    private TextBox textBox;
    private FileBrowser fileBrowser;
    private SplashScreen splashScreen;
    //</editor-fold>//GEN-END:|fields|0|

    /**
     * The FileBrowserExample constructor.
     */
    public FileBrowserExample() {
    }

    //<editor-fold defaultstate="collapsed" desc=" Generated Methods ">//GEN-BEGIN:|methods|0|
    //</editor-fold>//GEN-END:|methods|0|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: initialize ">//GEN-BEGIN:|0-initialize|0|0-preInitialize
    /**
     * Initilizes the application.
     * It is called only once when the MIDlet is started. The method is called before the <code>startMIDlet</code> method.
     */
    private void initialize() {//GEN-END:|0-initialize|0|0-preInitialize
        // write pre-initialize user code here
//GEN-LINE:|0-initialize|1|0-postInitialize
        // write post-initialize user code here
    }//GEN-BEGIN:|0-initialize|2|
    //</editor-fold>//GEN-END:|0-initialize|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: startMIDlet ">//GEN-BEGIN:|3-startMIDlet|0|3-preAction
    /**
     * Performs an action assigned to the Mobile Device - MIDlet Started point.
     */
    public void startMIDlet() {//GEN-END:|3-startMIDlet|0|3-preAction
        // write pre-action user code here
        switchDisplayable(null, getSplashScreen());//GEN-LINE:|3-startMIDlet|1|3-postAction
        // write post-action user code here
    }//GEN-BEGIN:|3-startMIDlet|2|
    //</editor-fold>//GEN-END:|3-startMIDlet|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: resumeMIDlet ">//GEN-BEGIN:|4-resumeMIDlet|0|4-preAction
    /**
     * Performs an action assigned to the Mobile Device - MIDlet Resumed point.
     */
    public void resumeMIDlet() {//GEN-END:|4-resumeMIDlet|0|4-preAction
        // write pre-action user code here
//GEN-LINE:|4-resumeMIDlet|1|4-postAction
        // write post-action user code here
    }//GEN-BEGIN:|4-resumeMIDlet|2|
    //</editor-fold>//GEN-END:|4-resumeMIDlet|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: switchDisplayable ">//GEN-BEGIN:|5-switchDisplayable|0|5-preSwitch
    /**
     * Switches a current displayable in a display. The <code>display</code> instance is taken from <code>getDisplay</code> method. This method is used by all actions in the design for switching displayable.
     * @param alert the Alert which is temporarily set to the display; if <code>null</code>, then <code>nextDisplayable</code> is set immediately
     * @param nextDisplayable the Displayable to be set
     */
    public void switchDisplayable(Alert alert, Displayable nextDisplayable) {//GEN-END:|5-switchDisplayable|0|5-preSwitch
        // write pre-switch user code here
        Display display = getDisplay();//GEN-BEGIN:|5-switchDisplayable|1|5-postSwitch
        if (alert == null) {
            display.setCurrent(nextDisplayable);
        } else {
            display.setCurrent(alert, nextDisplayable);
        }//GEN-END:|5-switchDisplayable|1|5-postSwitch
        // write post-switch user code here
    }//GEN-BEGIN:|5-switchDisplayable|2|
    //</editor-fold>//GEN-END:|5-switchDisplayable|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Getter: backCommand ">//GEN-BEGIN:|23-getter|0|23-preInit
    /**
     * Returns an initiliazed instance of backCommand component.
     * @return the initialized component instance
     */
    public Command getBackCommand() {
        if (backCommand == null) {//GEN-END:|23-getter|0|23-preInit
            // write pre-init user code here
            backCommand = new Command("Back", Command.BACK, 0);//GEN-LINE:|23-getter|1|23-postInit
            // write post-init user code here
        }//GEN-BEGIN:|23-getter|2|
        return backCommand;
    }
    //</editor-fold>//GEN-END:|23-getter|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Getter: exitCommand ">//GEN-BEGIN:|26-getter|0|26-preInit
    /**
     * Returns an initiliazed instance of exitCommand component.
     * @return the initialized component instance
     */
    public Command getExitCommand() {
        if (exitCommand == null) {//GEN-END:|26-getter|0|26-preInit
            // write pre-init user code here
            exitCommand = new Command("Exit", Command.EXIT, 0);//GEN-LINE:|26-getter|1|26-postInit
            // write post-init user code here
        }//GEN-BEGIN:|26-getter|2|
        return exitCommand;
    }
    //</editor-fold>//GEN-END:|26-getter|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Displayables ">//GEN-BEGIN:|7-commandAction|0|7-preCommandAction
    /**
     * Called by a system to indicated that a command has been invoked on a particular displayable.
     * @param command the Command that was invoked
     * @param displayable the Displayable where the command was invoked
     */
    public void commandAction(Command command, Displayable displayable) {//GEN-END:|7-commandAction|0|7-preCommandAction
        // write pre-action user code here
        if (displayable == fileBrowser) {//GEN-BEGIN:|7-commandAction|1|19-preAction
            if (command == FileBrowser.SELECT_FILE_COMMAND) {//GEN-END:|7-commandAction|1|19-preAction
                readFile();
                switchDisplayable(null, getTextBox());//GEN-LINE:|7-commandAction|2|19-postAction
                // write post-action user code here
            } else if (command == exitCommand) {//GEN-LINE:|7-commandAction|3|27-preAction
                // write pre-action user code here
                exitMIDlet();//GEN-LINE:|7-commandAction|4|27-postAction
                // write post-action user code here
            }//GEN-BEGIN:|7-commandAction|5|15-preAction
        } else if (displayable == splashScreen) {
            if (command == SplashScreen.DISMISS_COMMAND) {//GEN-END:|7-commandAction|5|15-preAction
                // write pre-action user code here
                switchDisplayable(null, getFileBrowser());//GEN-LINE:|7-commandAction|6|15-postAction
                // write post-action user code here
            }//GEN-BEGIN:|7-commandAction|7|24-preAction
        } else if (displayable == textBox) {
            if (command == backCommand) {//GEN-END:|7-commandAction|7|24-preAction
                // write pre-action user code here
                switchDisplayable(null, getFileBrowser());//GEN-LINE:|7-commandAction|8|24-postAction
                // write post-action user code here
            }//GEN-BEGIN:|7-commandAction|9|7-postCommandAction
        }//GEN-END:|7-commandAction|9|7-postCommandAction
        // write post-action user code here
    }//GEN-BEGIN:|7-commandAction|10|
    //</editor-fold>//GEN-END:|7-commandAction|10|

    //<editor-fold defaultstate="collapsed" desc=" Generated Getter: splashScreen ">//GEN-BEGIN:|13-getter|0|13-preInit
    /**
     * Returns an initiliazed instance of splashScreen component.
     * @return the initialized component instance
     */
    public SplashScreen getSplashScreen() {
        if (splashScreen == null) {//GEN-END:|13-getter|0|13-preInit
            // write pre-init user code here
            splashScreen = new SplashScreen(getDisplay());//GEN-BEGIN:|13-getter|1|13-postInit
            splashScreen.setTitle("splashScreen");
            splashScreen.setCommandListener(this);
            splashScreen.setText("File Browser Example");//GEN-END:|13-getter|1|13-postInit
            // write post-init user code here
        }//GEN-BEGIN:|13-getter|2|
        return splashScreen;
    }
    //</editor-fold>//GEN-END:|13-getter|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Getter: fileBrowser ">//GEN-BEGIN:|17-getter|0|17-preInit
    /**
     * Returns an initiliazed instance of fileBrowser component.
     * @return the initialized component instance
     */
    public FileBrowser getFileBrowser() {
        if (fileBrowser == null) {//GEN-END:|17-getter|0|17-preInit
            // write pre-init user code here
            fileBrowser = new FileBrowser(getDisplay());//GEN-BEGIN:|17-getter|1|17-postInit
            fileBrowser.setTitle("fileBrowser");
            fileBrowser.setCommandListener(this);
            fileBrowser.addCommand(FileBrowser.SELECT_FILE_COMMAND);
            fileBrowser.addCommand(getExitCommand());//GEN-END:|17-getter|1|17-postInit
            // write post-init user code here
        }//GEN-BEGIN:|17-getter|2|
        return fileBrowser;
    }
    //</editor-fold>//GEN-END:|17-getter|2|

    //<editor-fold defaultstate="collapsed" desc=" Generated Getter: textBox ">//GEN-BEGIN:|21-getter|0|21-preInit
    /**
     * Returns an initiliazed instance of textBox component.
     * @return the initialized component instance
     */
    public TextBox getTextBox() {
        if (textBox == null) {//GEN-END:|21-getter|0|21-preInit
            // write pre-init user code here
            textBox = new TextBox("textBox", null, 100, TextField.ANY);//GEN-BEGIN:|21-getter|1|21-postInit
            textBox.addCommand(getBackCommand());
            textBox.setCommandListener(this);//GEN-END:|21-getter|1|21-postInit
            // write post-init user code here
        }//GEN-BEGIN:|21-getter|2|
        return textBox;
    }
    //</editor-fold>//GEN-END:|21-getter|2|
    
    /**
     * Loads text file
     */ 
    private void readFile() {
        try {
            FileConnection textFile = fileBrowser.getSelectedFile();
            getTextBox().setString("");
            InputStream fis = textFile.openInputStream();
            byte[] b = new byte[1024];
            int length = fis.read(b, 0, 1024);
            fis.close();
            if (length > 0) {
                textBox.setString(new String(b, 0, length));
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
    
    /**
     * Returns a display instance.
     * @return the display instance.
     */
    public Display getDisplay () {
        return Display.getDisplay(this);
    }

    /**
     * Exits MIDlet.
     */
    public void exitMIDlet() {
        switchDisplayable (null, null);
        destroyApp(true);
        notifyDestroyed();
    }

    /**
     * Called when MIDlet is started.
     * Checks whether the MIDlet have been already started and initialize/starts or resumes the MIDlet.
     */
    public void startApp() {
        if (midletPaused) {
            resumeMIDlet ();
        } else {
            initialize ();
            startMIDlet ();
        }
        midletPaused = false;
    }

    /**
     * Called when MIDlet is paused.
     */
    public void pauseApp() {
        midletPaused = true;
    }

    /**
     * Called to signal the MIDlet to terminate.
     * @param unconditional if true, then the MIDlet has to be unconditionally terminated and all resources has to be released.
     */
    public void destroyApp(boolean unconditional) {
    }

}