I have a file that has strings hand typed as \u00C3. I want to create a unicode character that is being represented by that unicode in java. I tried but could not find how. Help.
Edit: When I read the text file String will contain "\u00C3" not as unicode but as ASCII chars '\' 'u' '0' '0' '3'. I would like to form unicode character from that ASCII string.
I picked this up somewhere on the web:
String unescape(String s) {
int i=0, len=s.length();
char c;
StringBuffer sb = new StringBuffer(len);
while (i < len) {
c = s.charAt(i++);
if (c == '\\') {
if (i < len) {
c = s.charAt(i++);
if (c == 'u') {
// TODO: check that 4 more chars exist and are all hex digits
c = (char) Integer.parseInt(s.substring(i, i+4), 16);
i += 4;
} // add other cases here as desired...
}
} // fall through: \ escapes itself, quotes any character but u
sb.append(c);
}
return sb.toString();
}
Dang, I was a bit slow. Here's my solution:
package ravi;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.regex.Pattern;
public class Ravi {
private static final Pattern UCODE_PATTERN = Pattern.compile("\\\\u[0-9a-fA-F]{4}");
public static void main(String[] args) throws Exception {
BufferedReader br = new BufferedReader(new FileReader("ravi.txt"));
while (true) {
String line = br.readLine();
if (line == null) break;
if (!UCODE_PATTERN.matcher(line).matches()) {
System.err.println("Bad input: " + line);
} else {
String hex = line.substring(2,6);
int number = Integer.parseInt(hex, 16);
System.out.println(hex + " -> " + ((char) number));
}
}
}
}
If you want to escape only unicode and nothing else, programmatically, you can create a function:
private String unicodeUnescape(String string) {
return new UnicodeUnescaper().translate(string);
}
This uses org.apache.commons.text.translate.UnicodeUnescaper.
Probably something along the lines:
Scanner s = new Scanner( new File("myNumbers") );
while( s.hasNextLine() ) {
System.out.println(
Character.valueOf(
(char)(int) Integer.valueOf(
s.nextLine().substring(2,6), 16
)
)
);
