UTF-8 character encoding in Java

Question

I am having some problems getting some French text to convert to UTF8 so that it can be displayed properly, either in a console, text file or in a GUI element.

The original string is

HANDICAP╔ES

which is supposed to be

HANDICAPÉES

Here is a code snippet that shows how I am using the jackcess Database driver to read in the Acccess MDB file in an Eclipse/Linux environment.

Database database = Database.open(new File(filepath));
Table table = database.getTable(tableName, true);
Iterator rowIter = table.iterator();
while (rowIter.hasNext()) {
    Map<String, Object> row = this.rowIter.next();
    // convert fields to UTF
    Map<String, Object> rowUTF = new HashMap<String, Object>();
    try {
        for (String key : row.keySet()) {
            Object o = row.get(key);
            if (o != null) {
                String valueCP850 = o.toString();
                // String nameUTF8 = new String(valueCP850.getBytes("CP850"), "UTF8"); // does not work!
                String valueISO = new String(valueCP850.getBytes("CP850"), "ISO-8859-1");
                String valueUTF8 = new String(valueISO.getBytes(), "UTF-8"); // works!
                rowUTF.put(key, valueUTF8);
            }
        }
    } catch (UnsupportedEncodingException e) {
        System.err.println("Encoding exception: " + e);
    }   
}

In the code you'll see where I want to convert directly to UTF8, which doesn't seem to work, so I have to do a double conversion. Also note that there doesn't seem to be a way to specify the encoding type when using the jackcess driver.

Thanks, Cam

Answer 1

New analysis, based on new information.
It looks like your problem is with the encoding of the text before it was stored in the Access DB. It seems it had been encoded as ISO-8859-1 or windows-1252, but decoded as cp850, resulting in the string HANDICAP╔ES being stored in the DB.

Having correctly retrieved that string from the DB, you're now trying to reverse the original encoding error and recover the string as it should have been stored: HANDICAPÉES. And you're accomplishing that with this line:

String valueISO = new String(valueCP850.getBytes("CP850"), "ISO-8859-1");

getBytes("CP850") converts the character ╔ to the byte value 0xC9, and the String constructor decodes that according to ISO-8859-1, resulting in the character É. The next line:

String valueUTF8 = new String(valueISO.getBytes(), "UTF-8");

...does nothing. getBytes() encodes the string in the platform default encoding, which is UTF-8 on your Linux system. Then the String constructor decodes it with the same encoding. Delete that line and you should still get the same result.

More to the point, your attempt to create a "UTF-8 string" was misguided. You don't need to concern yourself with the encoding of Java's strings--they're always UTF-16. When bringing text into a Java app, you just need to make sure you decode it with the correct encoding.

And if my analysis is correct, your Access driver is decoding it correctly; the problem is at the other end, possibly before the DB even comes into the picture. That's what you need to fix, because that new String(getBytes()) hack can't be counted on to work in all cases.

---

Original analysis, based on no information. :-/
If you're seeing HANDICAP╔ES on the console, there's probably no problem. Given this code:

System.out.println("HANDICAPÉES");

The JVM converts the (Unicode) string to the platform default encoding, windows-1252, before sending it to the console. Then the console decodes that using its own default encoding, which happens to be cp850. So the console displays it wrong, but that's normal. If you want it to display correctly, you can change the console's encoding with this command:

CHCP 1252

To display the string in a GUI element, such as a JLabel, you don't have to do anything special. Just make sure you use a font that can display all the characters, but that shouldn't be problem for French.

As for writing to a file, just specify the desired encoding when you create the Writer:

OutputStreamWriter osw = new OutputStreamWriter(
    new FileOutputStream("myFile.txt"), "UTF-8");