英文:
Java: Convert HEX byte array to 16 fixed length binary String
问题
private static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
public static String bytesToBinary(byte[] bytes) {
return hexToBin(bytesToHex(bytes));
}
public static String hexToBin(String s) {
if (StringUtils.isNotEmpty(s)) {
BigInteger bigInt = new BigInteger(s, 16);
int length = s.length() * 4; // Calculate the desired length of the binary string
String binaryString = bigInt.toString(2);
// Pad the binary string with leading zeros if necessary
while (binaryString.length() < length) {
binaryString = "0" + binaryString;
}
return binaryString;
}
return "";
}
public static String bytesToHex(byte[] bytes) {
if (bytes != null && bytes.length > 0) {
char[] hexChars = new char[bytes.length * 2];
for (int j = 0; j < bytes.length; j++) {
int v = bytes[j] & 0xFF;
hexChars[j * 2] = HEX_ARRAY[v >>> 4];
hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
}
return new String(hexChars);
}
return "";
}
英文:
I have a byte array obtained by automatically MYBATIS conversion.
Into ORACLE DB column (RAW type) I have HEX value (example: 0x0, 0x81, 0xC801).
This value is stored with maximum 2 bytes (example 1100100000000001 -> 0xC801, 0000000000000000 -> 0x0)
I have a problem when i read and convert this value.
I need to convert the byte array obtained by automatically conversion, to 16 fixed length binary string.
For example if the value in DB is 0x0:
- byte array is [0] (automatically MYBATIS conversion)
- binary string that I need must be 0000000000000000
For example if the value in DB is 0xC801:
- byte array is [0, -56, 1] (automatically MYBATIS conversion)
- binary string that I need must be 1100100000000001
How i can do that?
I tried with this solution but doesn't work with HEX value like 0x0 or 0x81 because 0x0 is mapped to "0" and 0x81 is mapped to "100000001". 0 padding is missing... and i don't know how to add the padding insite this script.
private static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
public static String bytesToBinary(byte[] bytes) {
return hexToBin(bytesToHex(bytes));
}
public static String hexToBin(String s) {
if (StringUtils.isNotEmpty(s)) {
return new BigInteger(s, 16).toString(2);
}
return "";
}
public static String bytesToHex(byte[] bytes) {
if (bytes != null && bytes.length > 0) {
char[] hexChars = new char[bytes.length * 2];
for (int j = 0; j < bytes.length; j++) {
int v = bytes[j] & 0xFF;
hexChars[j * 2] = HEX_ARRAY[v >>> 4];
hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
}
return new String(hexChars);
}
return "";
}
答案1
得分: 2
使用 BigInteger 尝试一下：
byte[] bytes = {0, -56, 1};
String result = new BigInteger(bytes).setBit(16).toString(2).substring(1);
System.out.println(result);
输出结果为：
1100100000000001
英文:
Try using BigInteger
byte[] bytes = {0, -56, 1};
// array, offset, length
String result = new BigInteger(bytes).setBit(16).toString(2).substring(1);
System.out.println(result);
Prints
1100100000000001
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