本地读取图片转化为byte[]

public void read(){
		String imagePath = "d:/lxp.bmp";
		byte[] tmp = new byte[4096]; 
		
		ByteArrayOutputStream buffer = new ByteArrayOutputStream();
		InputStream in = null;
		try {
			in = new FileInputStream(imagePath);
			int len;
			while((len = in.read(tmp)) != -1){
				buffer.write(tmp,0,len);
			}
			imageData = buffer.toByteArray();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			try {
				if(in != null)
				in.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}