Java 图片与byte数组互相转换实例

实例如下：

//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();

}

文件解析：

FileImageOutputStream 换成了 FileOutputStream
FileImageInputStream 换成 FileInputStream