Question

I’m searching for a library (Apache / BSD / EPL licensed) to convert native text to ASCII using \u for characters not available in ASCII (basically what java.util.Properties does).

I had a look and there don’t seem to be any readily available libraries. I found:

• JDK, tools.jar, native2ascii
• Properties.saveConvert() (private method)
• http://www.koders.com/java/fidD26ED81BEBE41932C405904AD53AEE8459BB8509.aspx (GPL)

Is anyone aware of a library under the above stated licenses?

Answer 1

You can do this with an CharsetEncoder. You have to read the ‘native’ Text with the correct encoding to unicode. Than you can use an ‘US-ASCII’-encoder to detect, which characters are to be translated into unicode escapes.

import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;

import org.junit.Test;

public class EncodeToEscapes {

@Test
public void testEncoding() {
    final String src = "Hallo äöü"; // this has to be read with the right encoding
    final CharsetEncoder asciiEncoder = Charset.forName("US-ASCII").newEncoder();
    final StringBuilder result = new StringBuilder();
    for (final Character character : src.toCharArray()) {
        if (asciiEncoder.canEncode(character)) {
            result.append(character);
        } else {
            result.append("\\u");
            result.append(Integer.toHexString(0x10000 | character).substring(1).toUpperCase());
        }
    }
    System.out.println(result);
 }
}

Additionally org.apache.commons:commons-lang contains StringEscapeUtils.escapeJava() which can escape and unescape native strings.