import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;import javax.imageio.IIOException;
import javax.imageio.ImageIO;public class ImageUtils {/*** 对图片进行放大或者压缩* * @param srcPath*            原始图片路径(绝对路径)* @param newPath*            处理后图片路径（绝对路径）* @param w*            目标宽度* @param h*            目标高度* @return 是否处理成功*/public static boolean zoomInImage(String srcPath, String newPath,Integer w, Integer h) {BufferedImage bufferedImage = null;try {File file = new File(srcPath);if (file.canRead()) {try{bufferedImage = ImageIO.read(file);}catch(IIOException e){e.printStackTrace();return false;}} else {System.out.println("文件不存在或没有权限读取：" + srcPath);return false;}} catch (IOException e) {// TODO: 打印日志e.printStackTrace();return false;}if (bufferedImage != null) {bufferedImage = zoomInImage(bufferedImage, w, h);try {// 保存修改后的图像,全部保存为JPG格式ImageIO.write(bufferedImage, "JPG", new File(newPath)); System.out.println("压缩后的图片已保存到磁盘");} catch (IOException e) {// TODO 打印错误信息e.printStackTrace();return false;}}return true;}/*** 对图片进行放大或者压缩处理* * @param originalImage*            原始图片* @param times*            放大倍数* @return*/public static BufferedImage zoomInImage(BufferedImage originalImage,Integer width, Integer height) {BufferedImage newImage = new BufferedImage(width, height,originalImage.getType());Graphics g = newImage.getGraphics();g.drawImage(originalImage, 0, 0, width, height, null);System.out.println("图片压缩成功");g.dispose();return newImage;}/*** 将图片写入到磁盘* * @param img*            图片数据流* @param fileName*            文件保存时的名称*/public static void writeImageToDisk(byte[] img, String fileSrc) {try {File file = new File( fileSrc);FileOutputStream fops = new FileOutputStream(file);fops.write(img);fops.flush();fops.close();System.out.println("原图已下载到本地磁盘");} catch (Exception e) {e.printStackTrace();}}/*** 根据地址获得数据的字节流* * @param strUrl*            网络连接地址* @return*/public static byte[] getImageFromNetByUrl(String strUrl) {try {URL url = new URL(strUrl);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setConnectTimeout(5 * 1000);InputStream inStream = conn.getInputStream();// 通过输入流获取图片数据byte[] btImg = readInputStream(inStream);// 得到图片的二进制数据return btImg;} catch (Exception e) {e.printStackTrace();}return null;}/*** 从输入流中获取数据* * @param inStream*            输入流* @return* @throws Exception*/public static byte[] readInputStream(InputStream inStream) throws Exception {ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while ((len = inStream.read(buffer)) != -1) {outStream.write(buffer, 0, len);}inStream.close();return outStream.toByteArray();}public static void main(String[] args) {// 图片url，压缩后的宽和高String url = "/upload/c671c57023e6eb83a1fa492babf0779e.jpg";int w = 700;int h = 500;//获取图片访问真实urlif(url.startsWith("/")){url = "http://localhost"+url;}String newDir = "/var/imgcompress/";String newName = MD5Util.encodeMD5(url);//从网络下载图片并保存到本地磁盘String srcPath = newDir + newName + url.substring(url.indexOf("."));writeImageToDisk(getImageFromNetByUrl(url),srcPath);//压缩后的图片路径String filePath = newDir + newName + "_" + w + "_" + h+ url.substring(url.indexOf("."));System.out.println(filePath);// 测试boolean test = zoomInImage(srcPath, filePath, w, h);if (test) {System.out.println("ok");}}}