imagepersistence.java

J2ME图像处理演示程序,演示图像转换个效果

/**
 * 
 * @author Sam Huang
 * 这个类是我临时的实现，结构非常不好，因为不是本例的重点，所以先这样了，有兴趣的朋友请改进
 * 在产品代码里，大家应该参考其它好的例子进行RMS操作
 */
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import javax.microedition.lcdui.Image;
import javax.microedition.rms.RecordStore;
import javax.microedition.rms.RecordStoreException;
import javax.microedition.rms.RecordStoreNotFoundException;
import javax.microedition.rms.RecordStoreNotOpenException;


public class ImagePersistence {

	/*
	 * 
	 * 将RMS编号为index的图片从RMS里读出来
	 * 因为没有加删除图片的方法，因此号码是连续的，
	 * 如果添加了删除图片的方法，这个得修改
	 */
	public static Image load(int index) {
		int width = 0;
		int height = 0;
		RecordStore rStore = null;
		byte[] b = null;
		String imagename = null;
		Image image = null;
		int[] rawdata = null;
		ByteArrayInputStream bin = null;
		DataInputStream din = null;

		try {
			rStore = RecordStore.openRecordStore("imagefile", true);
			int i = rStore.getNumRecords();
			if (i < index)
				return null;

			if (rStore.getRecord(index) != null) {

				b = rStore.getRecord(index);

				bin = new ByteArrayInputStream(b);

				din = new DataInputStream(bin);

				imagename = din.readUTF();
				width = din.readInt();
				height = din.readInt();

				int remaining = (b.length
						- imagename.getBytes("ISO8859_1").length - 2 - 8) / 4;

				rawdata = new int[remaining];

				for (int k = 0; k < rawdata.length; k++) {
					rawdata[k] = din.readInt();
				}

				image = Image.createRGBImage(rawdata, width, height, false);

				bin.reset();
				din.close();

			}

		} catch (IOException e) {

			//e.printStackTrace();

		} catch (RecordStoreException recordstoreexception) {

			//recordstoreexception.printStackTrace();

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

		}

		return image;
	}

	/*
	 * 
	 * 从RMS里加载名字为imgName的图片,速度真的很慢呀
	 */
	public static Image load(String imgName) {
		int width = 0;
		int height = 0;
		RecordStore rStore = null;
		byte[] b = null;
		String imagename = null;
		Image image = null;
		int[] rawdata = null;
		ByteArrayInputStream bin = null;
		DataInputStream din = null;

		try {
			rStore = RecordStore.openRecordStore("imagefile", true);
			int i = rStore.getNumRecords();

			for (int j = 1; j < i + 1; j++) {

				if (rStore.getRecord(j) != null) {

					b = rStore.getRecord(j);

					bin = new ByteArrayInputStream(b);

					din = new DataInputStream(bin);

					imagename = din.readUTF();

					if (!imagename.equals(imgName)) {
						bin.reset();
						bin = null;
						din = null;
						b = null;
						continue;
					}

					width = din.readInt();
					height = din.readInt();

					int remaining = (b.length
							- imagename.getBytes("ISO8859_1").length - 2 - 8) / 4;

					rawdata = new int[remaining];

					for (int k = 0; k < rawdata.length; k++) {
						rawdata[k] = din.readInt();
					}

					image = Image.createRGBImage(rawdata, width, height, false);

					bin.reset();
					din.close();

				}
			}
		} catch (IOException e) {

			e.printStackTrace();

		} catch (RecordStoreException recordstoreexception) {

			recordstoreexception.printStackTrace();

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

		}

		return image;
	}

	/*
	 * 
	 * 将名字为imgName的图片保存到RMS里
	 */
	public static boolean save(Image img, String imgName) {

		RecordStore rStore = null;
		ByteArrayOutputStream baos = null;
		DataOutputStream dos = null;
		int width = img.getWidth();
		int height = img.getHeight();

		if (img == null || imgName == null) {

			throw new IllegalArgumentException("参数错误");

		}
		int[] imgRgbData = null;
		try {
			imgRgbData = new int[width * height];
			img.getRGB(imgRgbData, 0, width, 0, 0, width, height);
			baos = new ByteArrayOutputStream();
			dos = new DataOutputStream(baos);
			dos.writeUTF(imgName);
			dos.writeInt(width);
			dos.writeInt(height);
			for (int i = 0; i < imgRgbData.length; i++) {
				dos.writeInt(imgRgbData[i]);
			}

			// 打开RecordStore,如果不存在，则创建一个
			rStore = RecordStore.openRecordStore("imagefile", true);
			rStore.addRecord(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;
				}
				imgRgbData = null;
				baos = null;
				dos = null;
			} catch (RecordStoreNotOpenException recordstorenotopenexception) {
				recordstorenotopenexception.printStackTrace();
			} catch (RecordStoreException recordstoreexception) {
				recordstoreexception.printStackTrace();
			}

		}

		return true;
	}
	
	public static boolean clearRms(String recordStoreName) {
		try {
			RecordStore.deleteRecordStore(recordStoreName);
		} catch (RecordStoreNotFoundException e) {
			//e.printStackTrace();
			return false;

		} catch (RecordStoreException e) {
			//e.printStackTrace();
			return false;
		}
		return true;
	}

}