J2ME測試小工具（camera）

攝像頭操作往往是比較煩人的內容，往往不能用一個統一的代碼來使用所有的手機。
這個測試目前僅包含了基本的功能（預覽和快照）。

但是，我注釋掉的代碼中，還包含了其它一些JSR234中關於攝像頭操作的高級功能，比如自動聚焦，縮放，自動感光等等。有興趣的朋友，可以恢復那些代碼並結合JSR234的文檔，仔細研究研究。此外，我還寫了一個保存照片的DeviceWirteFile函數，可以用來檢測攝像頭的真實拍攝效果（我們的軟件需要對獲取的圖像進行解碼，所以有這樣的需求）。

 

import Java.util.Vector;

import Javax.microedition.lcdui.Canvas;
import Javax.microedition.lcdui.Command;
import Javax.microedition.lcdui.CommandListener;
import Javax.microedition.lcdui.Display;
import Javax.microedition.lcdui.Displayable;
import Javax.microedition.lcdui.Form;
import Javax.microedition.lcdui.Graphics;
import Javax.microedition.lcdui.Image;
import Javax.microedition.media.Manager;
import Javax.microedition.media.Player;
import Javax.microedition.media.control.VideoControl;
import Javax.microedition.midlet.MIDlet;

public class CameraMID extends MIDlet implements CommandListener ...{

    private MyCanvas canvas;

    private Player myPlayer;
    private VideoControl videoControl = null;
//    private FocusControl focusControl = null;
//    private ZoomControl zoomControl = null;
//    private ExposureControl exposureControl = null;

    private Vector er = new Vector();

    private Form form;

    private Command cmdPlay;
    private Command cmdError;
    private Command cmdQuit;

    public static CameraMID mid;

    public byte[] data;
    public Image img;

    public CameraMID() ...{
        form = new Form("test");
        cmdPlay = new Command("play", Command.OK, 0);
        cmdError = new Command("show error", Command.ITEM, 1);
        cmdQuit = new Command("quit", Command.EXIT, 2);
        form.addCommand(cmdPlay);
        form.addCommand(cmdError);
        form.addCommand(cmdQuit);
        form.setCommandListener(this);
        Display.getDisplay(this).setCurrent(form);

        canvas = new MyCanvas();
        mid = this;
        
        try ...{
            String str = System.getProperty("video.snapshot.encodings");
            if (null == str) ...{
                str = "SSN";
            } else ...{
                str = "SSY";
            }
            er.addElement(str);
        } catch (Exception e) ...{
            er.addElement(e.toString());
        }
    }

    public void commandAction(Command c, Displayable d) ...{
        if (c.equals(cmdPlay)) ...{
            Display.getDisplay(this).setCurrent(canvas);
            initPlayer();
        } else if (c.equals(cmdError)) ...{
            form.deleteAll();
            for (int i = 0; i < er.size(); i++) ...{
                form.append((String) er.elementAt(i));
            }
        } else if (c.equals(cmdQuit)) ...{
            notifyDestroyed();
        }
    }

    private void initPlayer() ...{
        new Thread() ...{
            public void run() ...{
                freePlayer();
                try ...{
                    myPlayer = Manager.createPlayer("capture://video");
                    myPlayer.realize();
                    videoControl = (VideoControl) myPlayer
                            .getControl("VideoControl");
                    videoControl.initDisplayMode(VideoControl.USE_DIRECT_VIDEO,
                            canvas);
                    myPlayer.start();
                    videoControl.setVisible(true);
                    videoControl.setDisplayLocation(20, 18);
                    videoControl.setDisplaySize(200, 230);
                } catch (Exception e) ...{
                    er.addElement(e.toString());
                }
//                try {
//                    focusControl = (FocusControl) myPlayer
                          .getControl("FocusControl");
//                    if (focusControl.isMacroSupported()) {
//                        focusControl.setMacro(true);
//                    }
//                    if (focusControl.isAutoFocusSupported()) {
//                        autoFocusFlg = true;
//                    } else {
//                        autoFocusFlg = false;
//                    }
//                } catch (Exception e) {
//                    er.addElement("focus " + e.toString());
//                }
//
//                try {
//                    zoomControl = (ZoomControl) myPlayer
//                            .getControl("ZoomControl");
//
//                    zoomControl.setDigitalZoom(100);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
                 zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                    zoomControl.setDigitalZoom(ZoomControl.NEXT);
//                } catch (Exception e) {
//                    er.addElement("zoom " + e.toString());
//                }
//
//                try {
//                    exposureControl = (ExposureControl) myPlayer
//                            .getControl("ExposureControl");
            exposureControl.setISO(0);
//                } catch (Exception e) {
//                    er.addElement("exposure " + e.toString());
//                }
            }
        }.start();
    }

    private void freePlayer() ...{
        try ...{
            myPlayer.stop();
            myPlayer.deallocate();
        } catch (Exception e) ...{
        }
        try ...{
            myPlayer.close();
        } catch (Exception e) ...{
        }
    }

    private void snapshot() ...{
        new Thread() ...{
            public void run() ...{
                try ...{
                    er.addElement("getSnapshot ");
                    data = videoControl.getSnapshot("encoding=jpeg&width=640&height=480");
                    er.addElement("getSnapshot end ");
                    img = Image.createImage(data, 0, data.length);
                    form.deleteAll();
                    form.append(img);
                    Display.getDisplay(mid).setCurrent(form);
                    er.addElement("end ");

                    String time = Long.toString(System.currentTimeMillis());
                    String path = "file:///C:/pictures/" + time + ".png";
                    DeviceWirteFile(data, path);
                } catch (Exception e) ...{
                    er.addElement("snapshot " + e.toString());
                }
            }
        }.start();
    }

    private void zoomIn() ...{
//        if (zoomControl != null) {
//            zoomControl.setDigitalZoom(ZoomControl.NEXT);
//        }
    }

    private void zoomOut() ...{
//        if (zoomControl != null) {
//            zoomControl.setDigitalZoom(ZoomControl.PREVIOUS);
//        }
    }

    public void autoFocus() ...{
        if (autoFocusFlg) ...{
//            try {
//                focusControl.setFocus(-1000);
//            } catch (Exception e) {
//                er.addElement("autofocus " + e.toString());
//            }
        }
    }

    private boolean autoFocusFlg = false;

    private class MyCanvas extends Canvas implements CommandListener ...{

        private Command cmdOK;
        private Command cmdBack;
        private Command cmdFocus;

        public MyCanvas() ...{
            cmdOK = new Command("snapshot", Command.OK, 0);
            cmdBack = new Command("back", Command.BACK, 1);
            cmdFocus = new Command("auto focus", Command.ITEM, 2);
            addCommand(cmdOK);
            addCommand(cmdBack);
            addCommand(cmdFocus);
            setCommandListener(this);
        }

        public void paint(Graphics g) ...{
        }

        public void commandAction(Command c, Displayable d) ...{
            if (c.equals(cmdOK)) ...{
                autoFocus();
                snapshot();
            } else if (c.equals(cmdBack)) ...{
                freePlayer();
                Display.getDisplay(mid).setCurrent(form);
            } else if (c.equals(cmdFocus)) ...{
                autoFocus();
            }
        }

        public void keyRepeated(int key) ...{
            int nk = getGameAction(key);
            switch (nk) ...{
           & nbsp;case UP:
            case LEFT:
                zoomIn();
                break;
            case DOWN:
            case RIGHT:
                zoomOut();
                break;
            }
        }

    }

    private void DeviceWirteFile(byte[] data, String fileName) throws Exception ...{
        // FileConnection conn = (FileConnection) Connector.open(fileName,
        // Connector.READ_WRITE);
        // if (conn.exists()) {
        // conn.delete();
        // conn.create();
        // } else {
        // conn.create();
        // }
        // OutputStream os = conn.openOutputStream();
        //
        // os.write(data);
        // os.flush();
        // os.close();
        // conn.close();
    }

     protected void destroyApp(boolean arg0) ...{
    }

    protected void pauseApp() ...{
    }

    protected void startApp() ...{
    }

}