graphicsredliningtaskutil.java

esri的ArcGIS Server超级学习模板程序（for java）

package com.esri.solutions.jitk.web.tasks.redlining.graphics;

import java.io.InputStream;
import java.io.FileInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.util.List;
import net.sf.image4j.codec.ico.ICODecoder;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import java.text.DateFormat;
import java.util.Date;

public class GraphicsRedliningTaskUtil {
	public GraphicsRedliningTaskUtil() {
	}

	private static byte[] getBytesFromFile(File file) {
		try{
			InputStream is = new FileInputStream(file);
			ByteArrayOutputStream bytestream = new ByteArrayOutputStream();

			final int DEFAULT_BUFFER_SIZE = 1024 * 4;
			byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
			int count = 0;
			int num = 0;

			while ((num = is.read(buffer)) != -1){
				bytestream.write(buffer, 0, num);
				count += num;
			}
			return bytestream.toByteArray();
		}
		catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	public static byte[] getBytesFromFile(String strInFile, String sessionId){
		try{
			File inFile = new File(strInFile);
			List<BufferedImage> images = ICODecoder.read(inFile);

			BufferedImage img = (BufferedImage)images.get(images.size()-1);
			
			// bytearray doesn't work, so, save the bytes to png
			String dstr = DateFormat.getDateTimeInstance().format(new Date());
			String filename = dstr.replaceAll(" ", "_");
			filename = "jitk_" + sessionId + "_" + filename.replaceAll(":", "_") + ".png";

			String pngFileName = System.getProperty("java.io.tmpdir") + System.getProperty("file.separator") + filename;
			File pngFile = new File(pngFileName);
			javax.imageio.ImageIO.write(img, "png", pngFile);
			byte[] data = getBytesFromFile(pngFile);
			pngFile.delete();
			return data;
		}
		catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}	

	public static String checkSize(byte[] data, int widthParam, int heightParam, int sizeParam){
		try{
			if (data.length > sizeParam * 1024) return "File size is too large. File can not be uploaded.";
			BufferedImage img = ImageIO.read(new ByteArrayInputStream(data));
			int width = img.getWidth();
			int height = img.getHeight();
			if (width > widthParam || height > heightParam) return "File width or height is too large. File can not be uploaded.";
		}catch(Exception e){
			e.printStackTrace();
		}
		return "OK";
	}
}