formconf.java

j2me 图象缩小和放大。自动适应屏幕大小

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import javax.microedition.lcdui.ChoiceGroup;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.rms.RecordStore;
import javax.microedition.rms.RecordStoreException;
import javax.microedition.rms.RecordStoreNotOpenException;

public class FormConf extends Form implements CommandListener {

	private Command okCommand = new Command("保存", Command.OK, 2);

	private ChoiceGroup proxyCG = new ChoiceGroup("选择连接方式",
			ChoiceGroup.EXCLUSIVE, new String[] { "cmwap", "cmnet" }, null);

	public FormConf() {
		super("连接方式");
		super.addCommand(okCommand);
		super.append(this.proxyCG);
		if (ImageAlbum.getConnectionMethod()==null){
			this.proxyCG.setSelectedIndex(0,true);
		}else{
			if (ImageAlbum.getConnectionMethod().equals("cmwap")){
				this.proxyCG.setSelectedIndex(0,true);
			}else{
				this.proxyCG.setSelectedIndex(1,true);
			}
		}

	}

	public void commandAction(Command c, Displayable d) {
		String proxy = null;
		if (this.proxyCG.getSelectedIndex() == 0) {
			proxy = "cmwap";
		} else {
			proxy = "cmnet";
		}
		if (c == this.okCommand) {
            save(proxy);
            ImageAlbum.setConnectionMethod(proxy);
			ImageAlbum.setCurrentForm(ImageAlbum.getPreviousForm());
			ImageAlbum.getDisplay().setCurrent(ImageAlbum.getPreviousForm());
		}
	}

	/*
	 * 
	 * 将连接方式存入RMS
	 */
	public static boolean save(String connectonMethod) {

		RecordStore rStore = null;
		ByteArrayOutputStream baos = null;
		DataOutputStream dos = null;

		try {

			baos = new ByteArrayOutputStream();
			dos = new DataOutputStream(baos);
			dos.writeUTF(connectonMethod);
			// 打开RecordStore,如果不存在，则创建一个
			rStore = RecordStore.openRecordStore("CONNECTION_METHOD", true);
			if (rStore.getNumRecords() == 0) {
				rStore.addRecord(baos.toByteArray(), 0,
						baos.toByteArray().length); // Add
			} else {
				rStore.setRecord(1, baos.toByteArray(), 0,
						baos.toByteArray().length); // Add
			}

		} catch (Error oe) {
			// oe.printStackTrace();
			return false;
		} catch (Exception e) {
			 e.printStackTrace();
			return false;
		} finally {
			try {
				if (rStore != null) {
					rStore.closeRecordStore();
					rStore = null;
				}
				baos = null;
				dos = null;
			} catch (RecordStoreNotOpenException recordstorenotopenexception) {
				recordstorenotopenexception.printStackTrace();
			} catch (RecordStoreException recordstoreexception) {
				recordstoreexception.printStackTrace();
			}

		}

		return true;
	}

	/*
	 * 
	 * 将连接方式从RMS里读出来
	 */
	public static String loadConnectionMethod() {

		RecordStore rStore = null;
		byte[] b = null;
		ByteArrayInputStream bin = null;
		DataInputStream din = null;
		String connectionMethod = null;

		try {
			rStore = RecordStore.openRecordStore("CONNECTION_METHOD", true);
			if (rStore.getNumRecords() == 0) {
				return null;
			} else {
				b = rStore.getRecord(1);

				bin = new ByteArrayInputStream(b);

				din = new DataInputStream(bin);

				connectionMethod = din.readUTF();
			}
			bin.reset();
			din.close();

		} catch (IOException e) {

			e.printStackTrace();

		} catch (RecordStoreException recordstoreexception) {

			recordstoreexception.printStackTrace();

		} finally {
			try {
				rStore.closeRecordStore();
				rStore = null;
				b = null;
				din = null;
				bin = null;
			} catch (RecordStoreNotOpenException recordstorenotopenexception) {
				recordstorenotopenexception.printStackTrace();
			} catch (RecordStoreException recordstoreexception) {
				recordstoreexception.printStackTrace();
			}

		}

		return connectionMethod;
	}

}