【发布时间】：2012-01-27 07:04:03
【问题描述】：
我需要从接收到的 xml 文件中读取带有前导零的十六进制字符串，该字符串表示 JPEG 文件，并将其保存为图像文件。图像数据看起来像
0000005000000050FF191818FF151715FF111413FF0E1...........................FF2A2322FF292221
在xml文件中标签之间的字符串长度为51216我将Photo标签之间的十六进制数据作为字符串读取并将其转换为字节[]，并使用FileOutputStream我正在写入文件.但是当我尝试打开图像文件时，它告诉“文件似乎已损坏、损坏或文件太大”我尝试了很多方法来保存图像，但都没有成功。我列出了下面使用的方法。请帮我解决这个问题。
String photo="0000005000000050FF191818FF15"; //this is just a sample.The photo String actually contains the full Hex String which is 51216 long
//METHOD 1
String[] v = photo.split(" ");
byte[] arr = new byte[v.length];
int x = 0;
for(String val: v) {
arr[x++] = Integer.decode("0x" + val).byteValue();
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(arr);
fos.flush();
fos.close();
//METHOD 2
byte[] arr = new byte[photo.length()/2];
for ( int start = 0; start < photo.length(); start += 2 )
{
String thisByte = photo.substring(start, start+2);
arr[start/2] = Byte.parseByte(thisByte, 16);
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(arr);
fos.flush();
fos.close();
//METHOD 3
if ((photo.length() % 2) != 0)
throw new IllegalArgumentException("Input string must contain an even number of characters");
final byte result[] = new byte[photo.length()/2];
final char enc[] = photo.toCharArray();
for (int x = 0; x < enc.length; x += 2)
{
StringBuilder curr = new StringBuilder(2);
curr.append(enc[x]).append(enc[x + 1]);
result[x/2] = (byte) Integer.parseInt(curr.toString(), 16);
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(result);
fos.flush();
fos.close();
//METHOD 4
byte result[] = new byte[photo.length()/2];
char enc[] = photo.toUpperCase().toCharArray();
StringBuffer curr;
for (int x = 0; x < enc.length; x += 2)
{
curr = new StringBuffer("");
curr.append(String.valueOf(enc[x]));
curr.append(String.valueOf(enc[x + 1]));
result[x] = (byte) Integer.parseInt(curr.toString(), 16);
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(result);
fos.flush();
fos.close();
//METHOD 5
int len = photo.length();
byte[] data = new byte[len / 2];
for (int x = 0; x < len; x += 2)
{
data[x / 2] = (byte) ((Character.digit(photo.charAt(x), 16) << 4)
+ Character.digit(photo.charAt(x+1), 16));
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(data);
fos.flush();
fos.close();
//METHOD 6
byte[] bytes=new BigInteger(photo, 16).toByteArray();
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(bytes);
fos.flush();
fos.close();
//METHOD 7
byte[] bytes =DatatypeConverter.parseHexBinary(photo);
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(bytes);
fos.flush();
fos.close();
//METHOD 8
HexBinaryAdapter adapter = new HexBinaryAdapter();
byte[] bytes = adapter.unmarshal(photo);
FileOutputStream fos=new FileOutputStream("D:/Images/image6.png");
fos.write(bytes);
fos.flush();
fos.close();
//METHOD 9
byte data[] = new byte[photo.length()/2];
for(int x=0;i < photo.length();x+=2) {
data[x/2] = (Integer.decode("0x"+photo.charAt(x)+photo.charAt(x+1))).byteValue();
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(data);
fos.flush();
fos.close();
//METHOD 10
byte[] data = new byte[photo.length()/2];
for (int x=0;i<photo.length()/2;x++)
{
data[x] = (Integer.decode(
"0x"+photo.substring(x*2, (x+1)*2))).byteValue();
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(data);
fos.flush();
fos.close();
//METHOD 11
String hexVal ="0000005000000050FF";
//String hexVal = "0123456789ABCDEF";
byte[] out = new byte[photo.length() / 2];
int n = photo.length();
for( int x = 0; x < n; x += 2 ) {
int hn = hexVal.indexOf( photo.charAt( x ) );
int ln = hexVal.indexOf( photo.charAt( x + 1 ) );
out[x/2] = (byte)( ( hn << 4 ) | ln );
}
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(out);
fos.flush();
fos.close();
//METHOD 12
byte[] array=photo.getBytes();
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(array);
fos.flush();
fos.close();
//METHOD 13
byte[] array=photo.getBytes();
byte[] bytes = Base64.decode(array);
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(bytes);
fos.flush();
fos.close();
//METHOD 14
byte[] array=photo.getBytes();
Charset csets = Charset.forName("UTF-8");
ByteBuffer bb=ByteBuffer.wrap(array);
csets.decode(bb);
bb.rewind();
byte[] array1=bb.array();
FileOutputStream fos=new FileOutputStream("D:/Images/image6.jpg");
fos.write(array1);
fos.flush();
fos.close();
【问题讨论】：
-
如何“代表一个 JPG 文件”？它不是原始 JPG，也不是 JFIF 或 BASE64 或任何东西。
-
看起来它是十六进制编码的，但据我了解，JPG 不应该以 0x00、0x00 开头，而是以 0xff、0xd8 开头。见en.wikipedia.org/wiki/JPEG#Syntax_and_structure
-
嗨@Nick。你成功了吗？？