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Reading hexadecimal Unicode String from file and turn it into Java String?

I am writing currently a little parser for JSON documents.
UTF characters can be represented as \u0628.
How can I turn the string \u0628 into a real Java character?

you can use a piece of code like this:
String str = myString.split(" ")[0];
str = str.replace("\\","");
String[] arr = str.split("u");
String text = "";
for(int i = 1; i < arr.length; i++){
int hexVal = Integer.parseInt(arr[i], 16);
text += (char)hexVal;
}
or you can use Apache Commons Lang:
import org.apache.commons.lang.StringEscapeUtils;
#Test
public void testUnescapeJava() {
String sJava="\\u0048\\u0065\\u006C\\u006C\\u006F";
System.out.println("StringEscapeUtils.unescapeJava(sJava):\n" + StringEscapeUtils.unescapeJava(sJava));
}
output:
StringEscapeUtils.unescapeJava(sJava):
Hello

You can parse the bytes using the UTF_16 charset:
E.g.
byte[] data = {0x06, 0x28};
String string = new String(data, StandardCharsets.UTF_16);
You could find the escapes using a regex
private static Pattern ESCAPE_PATTERN = Pattern.compile("\\\\u([0-9a-fA-F]{2})([0-9a-fA-F]{2})");
public static String replaceCharEscapes(String input) {
Matcher m = ESCAPE_PATTERN.matcher(input);
if (!m.find()) {
return input;
}
StringBuilder outputBuilder = new StringBuilder(input.subSequence(0, m.start()));
int lastEnd = m.end();
outputBuilder.append(getChar(m));
while (m.find()) {
outputBuilder.append(input.subSequence(lastEnd, m.start()))
.append(getChar(m));
lastEnd = m.end();
}
if (lastEnd != input.length()) {
outputBuilder.append(input.subSequence(lastEnd, input.length()));
}
return outputBuilder.toString();
}
private static String getChar(Matcher m) {
return new String(new byte[] {
Byte.parseByte(m.group(1), 16),
Byte.parseByte(m.group(2), 16),
});
}
example:
replaceCharEscapes("\\u0043:\\\\u0050\\u0072\\u006f\\u0067\\u0072\\u0061\\u006ds")
returns C:\Programs

hex to string chinese,chinese hex 2 byte ,english hex 1byte?

this is stringToHexAsciiString.
//将字符串转成ASCII十六进制的java方法
public static String stringToHexAsciiString(String value)
{
StringBuffer sbu = new StringBuffer();
char[] chars = value.toCharArray();
for (int i = 0; i < chars.length; i++)
{
sbu.append(Integer.toHexString(chars[i]));
}
return sbu.toString();
}
this is asciiToString begin
//将ASCII转成字符串的java方法
public static String asciiToString(String value)
{
StringBuffer sbu = new StringBuffer();
//System.out.println("value.length()/2 = " + value.length()/2);
byte[] chars = new byte[value.length()/2];
chars = hexStringToByte(value);
//System.out.println("chars.length = " + chars.length);
for(int i=0; i<chars.length; i++){
//sbu.append((char) Integer.parseInt(chars[i]));
byte[] change = new byte[1];
change[0] = chars[i];
//System.out.println("change[0] = " + change[0]);
sbu.append((char) chars[i]);
//System.out.println("i = " + i + " " + sbu.toString());
}
return sbu.toString();
}
public static byte[] hexStringToByte(String hexString){
if (hexString == null || hexString.equals("")) {
return null;
}
hexString = hexString.toUpperCase();
int length = hexString.length() / 2;
char[] hexChars = hexString.toCharArray();
byte[] d = new byte[length];
for (int i = 0; i < length; i++) {
int pos = i * 2;
d[i] = (byte) (charToByte(hexChars[pos]) << 4 |charToByte(hexChars[pos + 1]));
// d[i] = (byte) (hexChars[pos] << 4 |hexChars[pos + 1]);
}
return d;
}
private static byte charToByte(char c) {
return (byte) "0123456789ABCDEF".indexOf(c);
}
use test english is ok,chinese is bad.
String strAscii = Encrypter.stringToHexAsciiString("汉1232").trim();
String asciiStr = Encrypter.asciiToString("6c4931323332".toUpperCase());
System.out.println("asciiStr:"+asciiStr);
System.out.println("strAscii:"+strAscii);
asciiToString result is chinese become messy code
asciiStr:lI1232
strAscii:6c4931323332
need to 汉1232.stringToHexAsciiString result :chinese char is 2 byte,english is 1 byte。how to div chinese hex and english hex。

I don't know what's the problem in your code... or what exactly you want, this is not clear in your question.
But if you just want convert a String to Hex format then you can try the following code:
import org.apache.commons.codec.binary.Hex;
public class StringToAscii
{
public static void main( String[] args )
{
try {
String s = "汉1232";
System.out.println(s);
String hexString = new String(Hex.encodeHexString(s.getBytes("UTF-8")));
System.out.println(hexString);
String unicode = new String(Hex.decodeHex(hexString.toCharArray()));
System.out.println(unicode);
}catch (Exception e)
{
e.printStackTrace();
}
}
}
The output on my laptop is:
汉1232
e6b18931323332
汉1232

Java equivalent of php pack('H*', str)

EDIT
I changed $checksum = md5($someString+$bkey); to $checksum = md5($someString.$bkey);
I need to perform the following operations in Java:
$hexString = '90aa';#sample value
$bkey = pack('H*',$hexString);
$someString='qwe';#sample value
$checksum = md5($someString.$bkey);
echo $checksum;
I can't convert hexString to bkey in Java to get the same result as php script. Except bkey everything is working properly.
If I remove bkey then:
PHP:
$someString='qwe';#sample value
$checksum = md5($someString);
echo $checksum;
result: 76d80224611fc919a5d54f0ff9fba446
Java:
String someString = "qwe";
MessageDigest messageDigest = MessageDigest.getInstance("MD5");
String checksum = new BigInteger(1, messageDigest.digest(someString
.getBytes())).toString(16);
System.out.println(checksum);
result: 76d80224611fc919a5d54f0ff9fba446
As you can see, it works
With bkey:
PHP:
$hexString = '90aa';#sample value
$bkey = pack('H*',$hexString);
$someString='qwe';#sample value
$checksum = md5($someString.$bkey);
echo $checksum;
result: 18f5f1a9bf898131945dd9e315759fe4
Java:
public static void main(String[] args) throws NoSuchAlgorithmException {
String hexString = "90aa";
String bkey = hexToString(hexString);
String someString = "qwe";
MessageDigest messageDigest = MessageDigest.getInstance("MD5");
String input = someString + bkey;
String checksum = new BigInteger(1, messageDigest.digest(input
.getBytes())).toString(16);
System.out.println(checksum);
}
public static String hexToString(String hex) {
StringBuilder output = new StringBuilder();
for (int i = 0; i < hex.length(); i += 2) {
String str = hex.substring(i, i + 2);
output.append((char) Integer.parseInt(str, 16));
}
return output.toString();
}
result: 44bb634dee436833dd65caa5043ffeb9
As you can see results are different.
How to convert hex String to String to get the same result?

The problem is not actually in your Java code, but in the PHP code.
The line $checksum = md5($someString+$bkey); does not do what you think it does, it should be:
$checksum = md5($someString . $bkey); # use concatenate, not sum
Although, that gives abetter PHP MD5, but does not help make the Java code match the PHP
EDIT
The problem on the Java side is in the character encoding. The Java char values for the inoacked versions of 90aa are not valid unicode characters. Thus the toByteArray() ,ethods ar enot doing great things. If you treat all of the Java code at a byte level (and ignore any high-bytes in any chars in the Java), then you get the same result as the PHP:
public static void main(String[] args) throws NoSuchAlgorithmException, UnsupportedEncodingException {
String hexString = "90aa";
byte[] bkey = hexToString(hexString);
String someString = "qwe";
MessageDigest messageDigest = MessageDigest.getInstance("MD5");
byte[] input = join(stringToBytes(someString), bkey);
String checksum = new BigInteger(1, messageDigest.digest(input)).toString(16);
System.out.println(checksum);
System.out.println(Charset.defaultCharset().displayName());
}
private static byte[] join(byte[] a, byte[] b) {
// join two byte arrays
final byte[] ret = new byte[a.length + b.length];
System.arraycopy(a, 0, ret, 0, a.length);
System.arraycopy(b, 0, ret, a.length, b.length);
return ret;
}
public static byte[] hexToString(String hex) {
// hexToString that works at a byte level, not a character level
byte[] output = new byte[(hex.length() + 1) / 2];
for (int i = hex.length() - 1; i >= 0; i -= 2) {
int from = i - 1;
if (from < 0) {
from = 0;
}
String str = hex.substring(from, i + 1);
output[i/2] = (byte)Integer.parseInt(str, 16);
}
return output;
}
public static byte[] stringToBytes(final String input) {
// unlike Stirng.toByteArray(), we ignore any high-byte values of the characters.
byte[] ret = new byte[input.length()];
for (int i = input.length() - 1; i >=0; i--) {
ret[i] = (byte)input.charAt(i);
}
return ret;
}
The above Java code produces the MD5sum 18f5f1a9bf898131945dd9e315759fe4 which is what PHP gives too

How to convert a binary representation of a string into byte in Java?

as the title says, how do I do it? Its easy to convert from string -> byte -> string binary, But how do I convert back? Below is a example.
The output is :
'f' to binary: 01100110
294984
I read somewhere that I could use the Integer.parseInt but clearly that is not the case :( Or am I doing something wrong?
Thanks,
:)
public class main{
public static void main(String[] args) {
String s = "f";
byte[] bytes = s.getBytes();
StringBuilder binary = new StringBuilder();
for (byte b : bytes)
{
int val = b;
for (int i = 0; i < 8; i++)
{
binary.append((val & 128) == 0 ? 0 : 1);
val <<= 1;
}
binary.append(' ');
}
System.out.println("'" + s + "' to binary: " + binary);
System.out.println(Integer.parseInt("01100110", 2));
}
}

You can use Byte.parseByte() with a radix of 2:
byte b = Byte.parseByte(str, 2);
Using your example:
System.out.println(Byte.parseByte("01100110", 2));
102

You can parse it to an integer in base 2, and convert to a byte array.
In your example you've got 16 bits you can also use short.
short a = Short.parseShort(b, 2);
ByteBuffer bytes = ByteBuffer.allocate(2).putShort(a);
byte[] array = bytes.array();
Just in case if you need it for a Very Big String.
String b = "0110100001101001";
byte[] bval = new BigInteger(b, 2).toByteArray();

I made like this, converted a string s -> byte[] and then used Integer.toBinaryString to get binaryStringRep. I converted bianryStringRep by using Byte.parseByte to get the bianryStringRep into byte and the String(newByte[]) to get the byte[] into a String! Hope it helps others then me aswell! ^^
public class main{
public static void main(String[] args) throws UnsupportedEncodingException {
String s = "foo";
byte[] bytes = s.getBytes();
byte[] newBytes = new byte[s.getBytes().length];
for(int i = 0; i < bytes.length; i++){
String binaryStringRep = String.format("%8s", Integer.toBinaryString(bytes[i] & 0xFF)).replace(' ', '0');
byte newByte = Byte.parseByte(binaryStringRep, 2);
newBytes[i] = newByte;
}
String str = new String(newBytes, "UTF-8");
System.out.println(str);
}
}

How can i change a string into the ascii values and back into a string?

I'm trying to make an simple encryption program that converts a string into the ASCII value equivalent and then decrypts it into the string again or char.
import java.io.*;
import javax.swing.*;
public class SimpleEncryption {
public static void main (String [] args) throws Exception
{
BufferedReader inKb = new BufferedReader (new InputStreamReader (System.in));
for(int i=0; i<10; i++)
{
String ans = JOptionPane.showInputDialog ("Hello User, would you like to encrypt or decrypt?");
ans = ans.toUpperCase();
int a = 0;
if (ans.contains("EN")||ans.contains("ENCRYPT"))
{
String pass = "";
pass = JOptionPane.showInputDialog ("Please type your phrase into input:");
for (int j=0; j<pass.length(); j++)
{
char c = pass.charAt(j);
a = (int) c;
System.out.print(a);
}
break;
}
if (ans.contains("DE")||ans.contains("DECRYPT"))
{
String pass = "";
pass = JOptionPane.showInputDialog ("Please type the encrypted code into input:");
for (int k=0; k<pass.length(); k++)
{
char c = pass.charAt(k);
a = (int)(c);
i = (char) a;
System.out.print(a);
}
break;
}
System.out.println("Sorry I don't understand, please retry.");
}
}
}

If what you're trying to have is in fact an encoding (before encryption ?) in ASCII of any java String (UTF-16 based), you might encode it in base64 : this encoding scheme was created just for that.
It's really easy to do this encoding/decoding in java (as in other languages).

What you seem to want is to get the byte array representing some kind of character encoding (not encryption) of the input string. Then you seem to want to show the octal value of the encoded characters. If you just need US ASCII then you would get all (printable) characters up to 177 octal. If you want special characters you need to choose a more specific character set (IBM OEM or Western-Latin are common ones). UTF-8 could also be used, but it may encode a single character into multiple bytes.
public static String toOctalString(final byte[] encoding) {
final StringBuilder sb = new StringBuilder(encoding.length * 4);
for (int i = 0; i < encoding.length; i++) {
if (i != 0) {
sb.append("|");
}
sb.append(Integer.toOctalString(encoding[i] & 0xFF));
}
return sb.toString();
}
public static byte[] fromOctalString(final String octalString) {
final ByteArrayOutputStream baos = new ByteArrayOutputStream(octalString.length() / 4 + 1);
final Matcher m = Pattern.compile("[0-7]{1,3}").matcher(octalString);
while (m.find()) {
baos.write(Integer.parseInt(m.group(), 8));
}
return baos.toByteArray();
}
public static void main(String[] args) {
final String userInput = "owlstæd";
// use the common Latin-1 encoding, standardized in ISO 8859 as character set 1
// you can replace with ASCII, but the ASCII characters will encode fine for both
final byte[] userInputEncoded = userInput.getBytes(Charset.forName("ISO8859-1"));
final String octalString = toOctalString(userInputEncoded);
System.out.println(octalString);
final byte[] userInputEncoded2 = fromOctalString(octalString);
final String userInput2 = new String(userInputEncoded2, Charset.forName("ISO8859-1"));
System.out.println(userInput2);
}