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Convert string representation of a hexadecimal byte array to a string with non ascii characters in Java

I have a String being sent in the request payload by a client as:
"[0xc3][0xa1][0xc3][0xa9][0xc3][0xad][0xc3][0xb3][0xc3][0xba][0xc3][0x81][0xc3][0x89][0xc3][0x8d][0xc3][0x93][0xc3][0x9a]Departms"
I want to get a String which is "áéíóúÁÉÍÓÚDepartms". How can I do this in Java?
The problem is that I have no control over the way client encodes this string. Seems like the client is just encoding the non-ascii characters in this format and sends the ascii chars as it is(see 'Departms' at the end).

The stuff within the square brackets, seems to be characters encoded in UTF-8 but converted into a hexadecimal string in a weird way. What you can do is find each instance that looks like [0xc3] and convert it into the corresponding byte, and then create a new string from the bytes.
Unfortunately there are no good tools for working with byte arrays. Here's a quick and dirty solution that uses regex to find and replace these hex codes with the corresponding character in latin-1, and then fixes that by re-interpreting the bytes.
String bracketDecode(String str) {
Pattern p = Pattern.compile("\\[(0x[0-9a-f]{2})\\]");
Matcher m = p.matcher(str);
StringBuilder sb = new StringBuilder();
while (m.find()) {
String group = m.group(1);
Integer decode = Integer.decode(group);
// assume latin-1 encoding
m.appendReplacement(sb, Character.toString(decode));
}
m.appendTail(sb);
// oh no, latin1 is not correct! re-interpret bytes in utf-8
byte[] bytes = sb.toString().getBytes(StandardCharsets.ISO_8859_1);
return new String(bytes, StandardCharsets.UTF_8);
}

Converting byte array to String Java

I wish to convert a byte array to String but as I do so, my String has 00 before every digit got from the array.
I should have got the following result: 49443a3c3532333437342e313533373936313835323237382e303e
But I have the following:
Please help me, how can I get the nulls away?
I have tried the following ways to convert:
xxxxId is the byteArray
String xxxIdString = new String(Hex.encodeHex(xxxxId));
Thank you!

Try something like this:
String s = new String(bytes);
s = s.replace("\0", "")
It's also posible, that the string will end after the first '\0' received, if thats the case, first iterate through the array and replace '\0' with something like '\n' and do this:
String s = new String(bytes);
s = s.replace("\n", "")
EDIT:
use this for a BYTE-ARRAY:
String s = new String(bytes, StandardCharsets.UTF_8);
use this for a CHAR:
String s = new String(bytes);

Try below code:
byte[] bytes = {...}
String str = new String(bytes, "UTF-8"); // for UTF-8 encoding
please have a look here- How to convert byte array to string and vice versa?

In order to convert Byte array into String format correctly, we have to explicitly create a String object and assign the Byte array to it.
String example = "This is an example";
byte[] bytes = example.getBytes();
String s = new String(bytes);

How to convert a string to another so that specific characters aren't allowed in the output?

I have a constraint: I cannot save some chars (like & and =) in a some special storage.
The problem is that I have strings (user input) that contain these not allowed special chars, which I'd like to save to that storage .
I'd like to convert such string to another string that wouldn't contain these special characters.
I'd like to still be able to convert back to the original string without creating ambiguity.
Any idea how to implement the de/convert? Thanks.

Convert the user input to Hex and save. And convert the hex value back to string. Use these methods.
public static String stringToHex(String arg) {
return String.format("%x", new BigInteger(1, arg.getBytes(Charset.forName("UTF-8"))));
}
public static String hexToString(String arg) {
byte[] bytes = DatatypeConverter.parseHexBinary(arg);
return new String(bytes, Charset.forName("UTF-8"));
}
Usage:
String h = stringToHex("Perera & Sons");
System.out.println(h);
System.out.println(hexToString(h));
OUTPUT
506572657261202620536f6e73
Perera & Sons

Already pointed out in the comments but URL Encoding looks like the way to go.
In Java done simply URLEncoder and URLDecoder
String encoded = URLEncoder.encode("My string &with& illegal = characters ", "UTF-8");
System.out.println("Encoded String:" + encoded);
String decoded = URLDecoder.decode(encoded, "UTF-8");
System.out.println("Decoded String:" + decoded);
URLEncoder
URLDecoder

Java Convert strange string to Burmese language string

Hi my example code is like ;
String ln="á€á€­á€•á€¹á€•á€¶á€”ဲ့";
try {
byte[] b = ln.getBytes("UTF-8");
String s = new String(b, "US-ASCII");
System.out.println(s);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
when I run it, it does not print Brumese, Is there a sloution for that ? Thanks

The real problem is that the server is sending back content either with the wrong charset, or double-encoded. If at all possible, you should get that fixed.
In the meantime, you have the right idea—converting the mis-encoded text to the correct charset.
Each character in your String was apparently supposed to be a single byte which was part of an UTF-8 byte sequence. What you're actually seeing is each of those single bytes being treated as a character in the Windows cp1252 charset, and converted to a Java char accordingly.
So, you first want to convert the chars from cp1252 back into the proper bytes:
byte[] b = ln.getBytes("cp1252");
Now you have a true UTF-8 byte sequence, which you can convert into the proper String:
String s = new String(b, StandardCharsets.UTF_8);
// In Java 6, you must use:
//String s = new String(b, "UTF-8");
You should never use US-ASCII if you are decoding, or trying to generate, Burmese characters, or any non-English characters. ASCII consists of codepoints 0 through 127 only.

Conversion from javascript-escaped Unicode to Java Unicode

I have a query string passed in through an HTTP request that has this character in it:
%u54E6
And I'd like to generate a string that contains the actual Chinese character so I can use it in a different part of the application, I've tried using this code:
String foo = "%u54E6";
String ufoo = new String(foo.replaceAll("%u([a-zA-Z0-9]{4})", "\\" + "u$1"));
System.out.println("ufoo: " + ufoo);
Unfortunately, all I'm getting is 'u54E6' printed to the console for the value, instead of the Chinese character.
Is there an easy way to convert the original string to a Unicode character in Java?

You're trying to use \u escapes at run time. These are compile-time only. Instead, you should be able to do something like:
String foo = "%u54E6";
Pattern p = Pattern.compile("%u([a-zA-Z0-9]{4})");
Matcher m = p.matcher(foo);
StringBuffer sb = new StringBuffer();
while (m.find()) {
m.appendReplacement(sb,
String.valueOf((char) Integer.parseInt(m.group(1), 16)));
}
m.appendTail(sb);
System.out.println(sb.toString());