设置图片品质 大小

 public static void toJPG(String source, String dest, int quality) throws JimiException {

  if (dest == null || dest.trim().equals(""))

   dest = source;

  if (!dest.toLowerCase().trim().endsWith("jpg")) {

   dest += ".jpg";

   System.out.println("Overriding to JPG, output file: " + dest);

  }

  if (quality < 0 || quality > 100 || (quality + "") == null

  || (quality + "").equals("")) {

   System.out.println("quality must between ’0’ and ’100’");

   System.out.println("set to DEFAULT value:’75’");

   quality = 100;

  }

  try {

   JPGOptions options = new JPGOptions();

   options.setQuality(quality);

   ImageProducer image = Jimi.getImageProducer(source);

   JimiWriter writer = Jimi.createJimiWriter(dest);

   writer.setSource(image);

   // 加入属性设置，非必要

   // /*

   writer.setOptions(options);

   // */
   writer.putImage(dest);
   
   OutputStream os = new ByteArrayOutputStream();
   
   writer.putImage(os);

  } catch (JimiException je) {

   throw je;

  }

 }
 
 public static void toJPG(InputStream input, String dest, int quality) throws JimiException {

  /*if (dest == null || dest.trim().equals(""))

   dest = source;*/

  if (!dest.toLowerCase().trim().endsWith("jpg")) {

   dest += ".jpg";

   System.out.println("Overriding to JPG, output file: " + dest);

  }

  if (quality < 0 || quality > 100 || (quality + "") == null

  || (quality + "").equals("")) {

   System.out.println("quality must between ’0’ and ’100’");

   System.out.println("set to DEFAULT value:’75’");

   quality = 100;

  }

  try {

   JPGOptions options = new JPGOptions();

   options.setQuality(quality);

   //ImageProducer image = Jimi.getImageProducer(source);
   ImageProducer image = Jimi.getImageProducer(input);

   JimiWriter writer = Jimi.createJimiWriter(dest);

   writer.setSource(image);

   // 加入属性设置，非必要

   // /*

   writer.setOptions(options);

   // */
   writer.putImage(dest);

  } catch (JimiException je) {

   throw je;

  }

 }

 /**
  *
  * 线性改变图片尺寸
  *
  * @param source
  *
  * 源文件完整路径
  *
  * @param desc
  *
  * 目标文件完整路径
  *
  * @param descWidth
  *
  * 图片期望宽度
  *
  * @param descHeight
  *
  * 图片期望高度
  * @throws Exception
  *
  */

 public void changeDimension(String source, String desc, int descWidth,
   int descHeight)

 throws Exception {

  String temp = desc;

  File _file = null;

  if (desc == null || desc.trim().equals(""))

   desc = source;

  if (!desc.toLowerCase().trim().endsWith("jpg")) {

   temp = desc.trim() + ".jpg";

  }

  this.toJPG(source, temp, 100);

  _file = new File(temp); // 读入文件

  Image src = javax.imageio.ImageIO.read(_file); // 构造Image对象

  double wideth = (double) src.getWidth(null); // 得到源图宽

  double height = (double) src.getHeight(null); // 得到源图长

  int iWideth = descWidth;

  int iHeight = descHeight;

  BufferedImage tag = new BufferedImage(iWideth, iHeight,

  BufferedImage.TYPE_INT_RGB);

  tag.getGraphics().drawImage(src, 0, 0, iWideth, iHeight, null); // 绘制缩小后的图

  if (!temp.trim().equals(desc))

   _file.deleteOnExit();

  if (desc.toLowerCase().trim().endsWith("jpg")) {

   JimiWriter writer = Jimi.createJimiWriter(desc);

   writer.setSource(tag);

   writer.putImage(desc);
  } else {
   throw new Exception("不支持此格式的图片尺寸的转换");
  }
 }

 /**
  *
  * 线性改变图片尺寸(可同时改变图片格式)
  *
  *
  *
  * @param source
  *
  * 源文件完整路径
  *
  * @param desc
  *
  * 目标文件完整路径
  *
  * @param ins
  *
  * 放大/缩小比率
  * @throws Exception
  *
  */
 public void changeDimension(String source, String desc, double percent)

 throws Exception {

  String temp = desc;

  File _file = null;

  if (desc == null || desc.trim().equals(""))

   desc = source;

  if (!desc.toLowerCase().trim().endsWith("jpg")) {

   temp = desc.trim() + ".jpg";

  }

  this.toJPG(source, temp, 100);

  _file = new File(temp); // 读入文件

  Image src = javax.imageio.ImageIO.read(_file); // 构造Image对象

  double wideth = (double) src.getWidth(null); // 得到源图宽

  double height = (double) src.getHeight(null); // 得到源图长

  int iWideth = (int) (wideth * percent);

  int iHeight = (int) (height * percent);

  BufferedImage tag = new BufferedImage(iWideth, iHeight,

  BufferedImage.TYPE_INT_RGB);

  tag.getGraphics().drawImage(src, 0, 0, iWideth, iHeight, null); // 绘制缩小后的图

  if (!temp.trim().equals(desc))

   _file.deleteOnExit();

  if (desc.toLowerCase().trim().endsWith("jpg")) {

   JimiWriter writer = Jimi.createJimiWriter(desc);

   writer.setSource(tag);

   writer.putImage(desc);
  } else {
   throw new Exception("不支持此格式的图片尺寸的转换");
  }

 }
 public byte [] toJPG(String source) throws IOException {
  ByteArrayOutputStream os = new ByteArrayOutputStream();
  File fin = new File(source);
  BufferedImage input = ImageIO.read(fin);
  ImageIO.write(input, "jpg", os);
  byte [] bytes = os.toByteArray();
  return bytes;
 }
 
 public byte[] toJPG(byte[] tempbytes) throws IOException {
  ByteArrayOutputStream os = new ByteArrayOutputStream();
  InputStream in = new ByteArrayInputStream(tempbytes);
  BufferedImage input = ImageIO.read(in);
  ImageIO.write(input, "jpg", os);
  byte [] bytes = os.toByteArray();
  return bytes;
 }
 
 public byte [] changeDimension(InputStream is,int expectWidth,int expectHeight) throws IOException {
  ByteArrayOutputStream os = new ByteArrayOutputStream();
  BufferedImage input = ImageIO.read(is);
  
  BufferedImage scaledBI = new BufferedImage(expectWidth, expectHeight,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g = scaledBI.createGraphics();
        g.setComposite(AlphaComposite.Src);
        g.drawImage(input, 0, 0, expectWidth, expectHeight, null);
        g.dispose();
        ImageIO.write(scaledBI, "jpg", os);
        byte [] descBytes = os.toByteArray();
  return descBytes;
 }
 
 public static boolean isJPG(byte[] bytes) {
  if (String.valueOf(bytes[0]).equals("-1") && String.valueOf(bytes[1]).equals("-40") && String.valueOf(bytes[2]).equals("-1") /*&& String.valueOf(bytes[3]).equals("-32")*/)
   return true;
  else
   return false;
 }
 public static boolean isPNG(byte[] bytes) {
  if(String.valueOf(bytes[0]).equals("-119") && String.valueOf(bytes[1]).equals("80") && String.valueOf(bytes[2]).equals("78") && String.valueOf(bytes[3]).equals("71"))
   return true;
  else
   return false;
 }
 public static boolean isGIF(byte[] bytes) {
  
  if (String.valueOf(bytes[0]).equals("71") && String.valueOf(bytes[1]).equals("73") && String.valueOf(bytes[2]).equals("70"))
   return true;
  else
   return false;
 }
 
 public static boolean isBMP(byte[] bytes) {
  if (String.valueOf(bytes[0]).equals("66") && String.valueOf(bytes[1]).equals("77"))
   return true;
  else
   return false;
 }
 
 public static byte[] getBytes(String filePath) throws Exception {
  File file = new File(filePath);
  InputStream input = new FileInputStream(file);
  ByteArrayOutputStream baos = new ByteArrayOutputStream();
  byte [] bytes = new byte [4096];
  int length = input.read(bytes);
  while(length != -1) {
   baos.write(bytes,0,length);
   length = input.read(bytes);
  }
  byte [] tempByte = baos.toByteArray();
  baos.close();
  input.close();
  return tempByte;
 }
 
 public double getPicLength(InputStream input) throws IOException {
  long lBytes = input.available();
  return ((double)lBytes/1024)/1024;
 }