Java 图片与byte数组互相转换实例

//图片到byte数组
 public byte[] image2byte(String path){
  byte[] data = null;
  FileImageInputStream input = null;
  try {
   input = new FileImageInputStream(new File(path));
   ByteArrayOutputStream output = new ByteArrayOutputStream();
   byte[] buf = new byte[1024];
   int numBytesRead = 0;
   while ((numBytesRead = input.read(buf)) != -1) {
   output.write(buf, 0, numBytesRead);
   }
   data = output.toByteArray();
   output.close();
   input.close();
  }
  catch (FileNotFoundException ex1) {
   ex1.printStackTrace();
  }
  catch (IOException ex1) {
   ex1.printStackTrace();
  }
  return data;
 }
 //byte数组到图片
 public void byte2image(byte[] data,String path){
  if(data.length<3||path.equals("")) return;
  try{
  FileImageOutputStream imageOutput = new FileImageOutputStream(new File(path));
  imageOutput.write(data, 0, data.length);
  imageOutput.close();
  System.out.println("Make Picture success,Please find image in " + path);
  } catch(Exception ex) {
   System.out.println("Exception: " + ex);
   ex.printStackTrace();
  }
 }
 //byte数组到16进制字符串
 public String byte2string(byte[] data){
  if(data==null||data.length<=1) return "0x";
  if(data.length>200000) return "0x";
  StringBuffer sb = new StringBuffer();
  int buf[] = new int[data.length];
  //byte数组转化成十进制
  for(int k=0;k<data.length;k++){
   buf[k] = data[k]<0?(data[k]+256):(data[k]);
  }
  //十进制转化成十六进制
  for(int k=0;k<buf.length;k++){
   if(buf[k]<16) sb.append("0"+Integer.toHexString(buf[k]));
   else sb.append(Integer.toHexString(buf[k]));
  }
  return "0x"+sb.toString().toUpperCase();

 }