import java.awt.Image; import java.awt.Toolkit; import java.awt.image.BufferedImage; import java.awt.image.MemoryImageSource; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import javax.imageio.ImageIO; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; /** *//** * @将文件转化为缩略图 * */ public class jpgThumbnail { private static final String BMP = "bmp"; private static final String PNG = "png"; private static final String GIF = "gif"; private static final String JPEG = "jpeg"; private static final String JPG = "jpg"; public static void getThumbnail( String source, String output, int width, int height) { boolean adjustSize=true; if (source == null || source.equals("") || width < 1 || height < 1) { return; } if(output==null || output.equals("")) { return; } source = source.toLowerCase(); if (source.endsWith(BMP)) { BMPThumbnailHandler(source, output,width, height, adjustSize); } else if (source.endsWith(PNG) || source.endsWith(GIF) || source.endsWith(JPEG) || source.endsWith(JPG)) { thumbnailHandler(source, output,width, height, adjustSize); } } private static void thumbnailHandler( String source, String output, int width, int height, boolean adjustSize) { try { File sourceFile = new File(source); if (sourceFile.exists()) { Image image = ImageIO.read(sourceFile); int theImgWidth = image.getWidth(null); int theImgHeight = image.getHeight(null); int[] size = { theImgWidth, theImgHeight }; if (adjustSize) { size = adjustImageSize(theImgWidth, theImgHeight, width,height); } StringBuffer thumbnailFile=new StringBuffer(); //thumbnailFile.append(sourceFile.getParent()); //thumbnailFile.append(File.separatorChar); thumbnailFile.append(output); writeFile(image, size[0], size[1], thumbnailFile.toString()); } } catch (Exception e) { e.printStackTrace(); return; } } private static void BMPThumbnailHandler( String source, String output, int width, int height, boolean adjustSize) { try { File sourceFile = new File(source); if (sourceFile.exists()) { Image image = getBMPImage(source); int theImgWidth = image.getWidth(null); int theImgHeight = image.getHeight(null); int[] size = { theImgWidth, theImgHeight }; if (adjustSize) { size = adjustImageSize(theImgWidth, theImgHeight, width, height); } StringBuffer thumbnailFile=new StringBuffer(); //thumbnailFile.append(sourceFile.getParent()); //thumbnailFile.append(File.separatorChar); thumbnailFile.append(output); writeFile(image, size[0], size[1], thumbnailFile.toString()); } } catch (Exception e) { e.printStackTrace(); return; } } private static Image getBMPImage(String source) throws Exception { FileInputStream fs = null; Image image = null; try { fs = new FileInputStream(source); int bfLen = 14; byte bf[] = new byte[bfLen]; fs.read(bf, 0, bfLen); // 读取14字节BMP文件头 int biLen = 40; byte bi[] = new byte[biLen]; fs.read(bi, 0, biLen); // 读取40字节BMP信息头 // 源图宽度 int nWidth = (((int) bi[7] & 0xff) << 24) | (((int) bi[6] & 0xff) << 16) | (((int) bi[5] & 0xff) << 8) | (int) bi[4] & 0xff; // 源图高度 int nHeight = (((int) bi[11] & 0xff) << 24) | (((int) bi[10] & 0xff) << 16) | (((int) bi[9] & 0xff) << 8) | (int) bi[8] & 0xff; // 位数 int nBitCount = (((int) bi[15] & 0xff) << 8) | (int) bi[14] & 0xff; // 源图大小 int nSizeImage = (((int) bi[23] & 0xff) << 24) | (((int) bi[22] & 0xff) << 16) | (((int) bi[21] & 0xff) << 8) | (int) bi[20] & 0xff; // 对24位BMP进行解析 if (nBitCount == 24) { int nPad = (nSizeImage / nHeight) - nWidth * 3; int nData[] = new int[nHeight * nWidth]; byte bRGB[] = new byte[(nWidth + nPad) * 3 * nHeight]; fs.read(bRGB, 0, (nWidth + nPad) * 3 * nHeight); int nIndex = 0; for (int j = 0; j < nHeight; j++) { for (int i = 0; i < nWidth; i++) { nData[nWidth * (nHeight - j - 1) + i] = (255 & 0xff) << 24 | (((int) bRGB[nIndex + 2] & 0xff) << 16) | (((int) bRGB[nIndex + 1] & 0xff) << 8) | (int) bRGB[nIndex] & 0xff; nIndex += 3; } nIndex += nPad; } Toolkit kit = Toolkit.getDefaultToolkit(); image = kit.createImage(new MemoryImageSource(nWidth, nHeight, nData, 0, nWidth)); } } catch (Exception e) { e.printStackTrace(); throw new Exception(e); } finally { if (fs != null) { fs.close(); } } return image; } private static void writeFile( Image image, int width, int height, String thumbnailFile) throws Exception { if (image == null) return; BufferedImage tag = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB); tag.getGraphics().drawImage(image, 0, 0, width, height, null); FileOutputStream out = null; try { out = new FileOutputStream(thumbnailFile); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); encoder.encode(tag); } catch (Exception e) { e.printStackTrace(); throw new Exception(e); } finally { if (out != null) { out.close(); } } } private static int[] adjustImageSize(int theImgWidth, int theImgHeight, int defWidth, int defHeight) { int[] size = { 0, 0 }; float theImgHeightFloat=Float.parseFloat(String.valueOf(theImgHeight)); float theImgWidthFloat=Float.parseFloat(String.valueOf(theImgWidth)); if (theImgWidth<theImgHeight){ float scale=theImgHeightFloat/theImgWidthFloat; size[0]=Math.round(defHeight/scale); size[1]=defHeight; }else{ float scale=theImgWidthFloat/theImgHeightFloat; size[0]=defWidth; size[1]=Math.round(defWidth/scale); } return size; } public static void main(String[] agrs) { //zoomPicture("E:\\1.jpg","E:\\test.jpg",60, 80); getThumbnail("E:\\1.jpg","E:\\test.jpg",60, 80); } }
