How to convert UTF8 to Unicode - java

I try to convert a UTF8 string to a Java Unicode string.
String question = request.getParameter("searchWord");
byte[] bytes = question.getBytes();
question = new String(bytes, "UTF-8");
The input are Chinese Characters and when I compare the hex code of each caracter it is the same Chinses character. So I'm pretty sure that the charset is UTF8.
Where do I go wrong?

There's no such thing as a "UTF-8 string" in Java. Everything is in Unicode.
When you call String.getBytes() without specifying an encoding, that uses the platform default encoding - that's almost always a bad idea.
You shouldn't have to do anything to get the right characters here - the request should be handling it all for you. If it's not doing so, then chances are it's lost data already.
Could you give an example of what's actually going wrong? Specify the Unicode values of the characters in the string you're receiving (e.g. by using toCharArray() and then converting each char to an int) and what you expected to receive.
EDIT: To diagnose this, use something like this:
public static void dumpString(String text) {
for (int i = 0; i < text.length(); i++) {
System.out.println(i + ": " + (int) text.charAt(i));
}
}
Note that that will give the decimal value of each Unicode character. If you have a handy hex library method around, you may want to use that to give you the hex value. The main point is that it will dump the Unicode characters in the string.

First make sure that the data is actually encoded as UTF-8.
There are some inconsistency between browsers regarding the encoding used when sending HTML form data. The safest way to send UTF-8 encoded data from a web form is to put that form on a page that is served with the Content-Type: text/html; charset=utf-8 header or contains a <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> meta tag.
Now to properly decode the data call request.setCharacterEncoding("UTF-8") in your servlet before the first call to request.getParameter().
The servlet container takes care of the encoding for you. If you use setCharacterEncoding() properly you can expect getParameter() to return normal Java strings.

Also you may need a special filter which will take care of encoding of your requests. For example such filter exists in spring framework org.springframework.web.filter.CharacterEncodingFilter

String question = request.getParameter("searchWord");
is all you have to do in your servlet code. At this point you have not to deal with encodings, charsets etc. This is all handled by the servlet-infrastucture. When you notice problems like displaying �, ?, ü somewhere, there is maybe something wrong with request the client sent. But without knowing something of the infrastructure or the logged HTTP-traffic, it is hard to tell what is wrong.

possibly.
question = new String(bytes, "UNICODE");

Related

How to handle  (object replacement character) in URL

Using Jsoup to scrape URLS and one of the URLS I keep getting has this  symbol in it. I have tried decoding the URL:
url = URLDecoder.decode(url, "UTF-8" );
but it still remains in the code looking like this:
I cant find much online about this other than it is "The object replacement character, sometimes used to represent an embedded object in a document when it is converted to plain text."
But if this is the case I should be able to print the symbol if it is plain text but when I run
System.out.println("");
I get the following complication error:
and it reverts back to the last save.
Sample URL: https://www.breightgroup.com/job/hse-advisor-embedded-contract-roles%ef%bf%bc/
NOTE: If you decode the url then compare it to the decoded url it comes back as not the same e.g.:
String url = URLDecoder.decode("https://www.breightgroup.com/job/hse-advisor-embedded-contract-roles%ef%bf%bc/", "UTF-8");
if(url.contains("https://www.breightgroup.com/job/hse-advisor-embedded-contract-roles?/")){
System.out.println("The same");
}else {
System.out.println("Not the same");
}
That's not a compilation error. That's the eclipse code editor telling you it can't save the source code to a file, because you have told it to save the file in a cp1252 encoding, but that encoding can't express a .
Put differently, your development environment is currently configured to store source code in the cp1252 encoding, which doesn't support the character you want, so you either configure your development environment to store source code using a more flexible encoding (such as UTF-8 the error message suggests), or avoid having that character in your source code, for instance by using its unicode escape sequence instead:
System.out.println("\ufffc");
Note that as far as the Java language and runtime are concerned,  is a character like any other, so there may not be a particular need to "handle" it. Also, I am unsure why you'd expect URLDecoder to do anything if the URL hasn't been URL-encoded to begin with.
"ef bf bc" is a 3 bytes UTF-8 character so as the error says, there's no representation for that character in "CP1252" Windows page encoding.
An option could be to replace that percent encoding sequence with an ascii representation to make the filename for saving:
String url = URLDecoder.decode("https://www.breightgroup.com/job/hse-advisor-embedded-contract-roles%ef%bf%bc/".replace("%ef%bf%bc", "-xEFxBFxBC"), "UTF-8");
url ==> "https://www.breightgroup.com/job/hse-advisor-emb ... contract-roles-xEFxBFxBC/"
Another option using CharsetDecoder
String urlDec = URLDecoder.decode("https://www.breightgroup.com/job/hse-advisor-embedded-contract-roles%ef%bf%bc/", "UTF-8");
CharsetDecoder decoder = Charset.forName("CP1252").newDecoder().onMalformedInput(CodingErrorAction.REPLACE).onUnmappableCharacter(CodingErrorAction.REPLACE);
String urlDec = URLDecoder.decode("https://www.breightgroup.com/job/hse-advisor-embedded-contract-roles%ef%bf%bc/", "UTF-8");
ByteBuffer buffer = ByteBuffer.wrap(urlDec.getBytes(Charset.forName("UTF-8")));
decoder.decode(buffer).toString();
Result
"https://www.breightgroup.com/job/hse-advisor-embedded-contract-roles/"
I found the issue resolved by just replacing URLs with this symbol because there are other URLs with Unicode symbols that were invisible that couldnt be converted ect..
So I just compared the urls to the following regex if it returns false then I just bypass it. Hope this helps someone out:
boolean newURL = url.matches("^[a-zA-Z0-9_:;/.&|%!+=#?-]*$");

Charset trouble (ø as 00F8)

I am getting a string from our database (third party tool) - and I have a trouble with one
name - sometimes it is right "Tarsøy", and all runs smoothly but sometimes it is "Tars00F8y".
And this ruins the process - I have tried to write some validator function via URLDecoder.decode(name, "UTF-8") that gets a string and return validated one but not succeed.
this is how I get a sting from our base:
Database.WIKI.get(index); // the index is the ID of the string
// this is no sql DB
now about "sometimes" - it means that this code just works different =) I think that is connected with inner DB exceptions or so. So I am trying to do something like validate(Database.WIKI.get(index))
May be I should try something like Encode String to UTF-8
In Java, JavaScript and (especially interesting) JSON there exists the notation \u00F8 for ø. I think this was sent to the database, maybe from a specific browser on a specific computer locale. \u disappeared and voilà. Maybe it is still as invisible control character in the string. That would be nice for repairs.
My guess is JSON data; however normally JSON libraries should parse u-escaped characters. That is weird.
Check what happens when storing "x\\u00FDx". Is the char length 6 or maybe 7 (lucky).
Some sanity checks: assuming you work in UTF-8, especially if the data arrive by HTML or JS:
Content-Type header text/html; charset=UTF-8
(Optional) meta tag with charset=UTF-8
<form action="..." accept-charset="UTF-8">
JSON: contentType: "application/json; charset=UTF-8"

Converting from Java String to Windows-1252 Format

I want to send a URL request, but the parameter values in the URL can have french characters (eg. è). How do I convert from a Java String to Windows-1252 format (which supports the French characters)?
I am currently doing this:
String encodedURL = new String (unencodedUrl.getBytes("UTF-8"), "Windows-1252");
However, it makes:
param=Stationnement extèrieur into param=Stationnement extérieur .
How do I fix this? Any suggestions?
Edit for further clarification:
The user chooses values from a drop down. When the language is French, the values from the drop down sometimes include French characters, like 'è'. When I send this request to the server, it fails, saying it is unable to decipher the request. I have to figure out how to send the 'è' as a different format (preferably Windows-1252) that supports French characters. I have chosen to send as Windows-1252. The server will accept this format. I don't want to replace each character, because I could miss a special character, and then the server will throw an exception.
Use URLEncoder to encode parameter values as application/x-www-form-urlencoded data:
String param = "param="
+ URLEncoder.encode("Stationnement extr\u00e8ieur", "cp1252");
See here for an expanded explanation.
Try using
String encodedURL = new String (unencodedUrl.getBytes("UTF-8"), Charset.forName("Windows-1252"));
As per McDowell's suggestion, I tried encoding doing:
URLEncoder.encode("stringValueWithFrechCharacters", "cp1252") but it didn't work perfectly. I replayced "cp1252" with HTTP.ISO_8859_1 because I believe Android does not have the support for Windows-1252 yet. It does allow for ISO_8859_1, and after reading here, this supports MOST of the French characters, with the exception of 'Œ', 'œ', and 'Ÿ'.
So doing this made it work:
URLEncoder.encode(frenchString, HTTP.ISO_8859_1);
Works perfectly!

Java string encoding conversion within a webpage

I have a webpage that is encoded (through its header) as WIN-1255.
A Java program creates text string that are automatically embedded in the page. The problem is that the original strings are encoded in UTF-8, thus creating a Gibberish text field in the page.
Unfortunately, I can not change the page encoding - it's required by a customer propriety system.
Any ideas?
UPDATE:
The page I'm creating is an RSS feed that needs to be set to WIN-1255, showing information taken from another feed that is encoded in UTF-8.
SECOND UPDATE:
Thanks for all the responses. I've managed to convert th string, and yet, Gibberish. Problem was that XML encoding should be set in addition to the header encoding.
Adam
To the point, you need to set the encoding of the response writer. With only a response header you're basically only instructing the client application which encoding to use to interpret/display the page. This ain't going to work if the response itself is written with a different encoding.
The context where you have this problem is entirely unclear (please elaborate about it as well in future problems like this), so here are several solutions:
If it is JSP, you need to set the following in top of JSP to set the response encoding:
<%# page pageEncoding="WIN-1255" %>
If it is Servlet, you need to set the following before any first flush to set the response encoding:
response.setCharacterEncoding("WIN-1255");
Both by the way automagically implicitly set the Content-Type response header with a charset parameter to instruct the client to use the same encoding to interpret/display the page. Also see this article for more information.
If it is a homegrown application which relies on the basic java.net and/or java.io API's, then you need to write the characters through an OutputStreamWriter which is constructed using the constructor taking 2 arguments wherein you can specify the encoding:
Writer writer = new OutputStreamWriter(someOutputStream, "WIN-1255");
Assuming you have control of the original (properly represented) strings, and simply need to output them in win-1255:
import java.nio.charset.*;
import java.nio.*;
Charset win1255 = Charset.forName("windows-1255");
ByteBuffer bb = win1255.encode(someString);
byte[] ba = new byte[bb.limit()];
Then, simply write the contents of ba at the appropriate place.
EDIT: What you do with ba depends on your environment. For instance, if you're using servlets, you might do:
ServletOutputStream os = ...
os.write(ba);
We also should not overlook the possible approach of calling setContentType("text/html; charset=windows-1255") (setContentType), then using getWriter normally. You did not make completely clear if windows-1255 was being set in a meta tag or in the HTTP response header.
You clarified that you have a UTF-8 file that you need to decode. If you're not already decoding the UTF-8 strings properly, this should no big deal. Just look at InputStreamReader(someInputStream, Charset.forName("utf-8"))
What's embedding the data in the page? Either it should read it as text (in UTF-8) and then write it out again in the web page's encoding (Win-1255) or you should change the Java program to create the files (or whatever) in Win-1255 to start with.
If you can give more details about how the system works (what's generating the web page? How does it interact with the Java program?) then it will make things a lot clearer.
The page I'm creating is an RSS feed that needs to be set to WIN-1255, showing information taken from another feed that is encoded in UTF-8.
In this case, use a parser to load the UTF-8 XML. This should correctly decode the data to UTF-16 character data (Java Strings are always UTF-16). Your output mechanism should encode from UTF-16 to Windows-1255.
byte[] originalUtf8;//Here input
//utf-8 to java String:
String internal = new String(originalUtf8,Charset.forName("utf-8");
//java string to w1255 String
byte[] win1255 = internal.getBytes(Charset.forName("cp1255"));
//Here output

UTF-8 character encoding in Java

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
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");
String s = "HANDICAP╔ES";
System.out.println(new String(s.getBytes("CP850"), "ISO-8859-1")); // HANDICAPÉES
This shows the correct string value. This means that it was originally encoded/decoded with ISO-8859-1 and then incorrectly encoded with CP850 (originally CP1252 a.k.a. Windows ANSI as pointed in a comment is indeed also possible since the É has the same codepoint there as in ISO-8859-1).
Align your environment and binary pipelines to use all the one and same character encoding. You can't and shouldn't convert between them. You would risk losing information in the non-ASCII range that way.
Note: do NOT use the above code snippet to "fix" the problem! That would not be the right solution.
Update: you are apparently still struggling with the problem. I'll repeat the important parts of the answer:
Align your environment and binary pipelines to use all the one and same character encoding.
You can not and should not convert between them. You would risk losing information in the non-ASCII range that way.
Do NOT use the above code snippet to "fix" the problem! That would not be the right solution.
To fix the problem you need to choose character encoding X which you'd like to use throughout the entire application. I suggest UTF-8. Update MS Access to use encoding X. Update your development environment to use encoding X. Update the java.io readers and writers in your code to use encoding X. Update your editor to read/write files with encoding X. Update the application's user interface to use encoding X. Do not use Y or Z or whatever at some step. If the characters are already corrupted in some datastore (MS Access, files, etc), then you need to fix it by manually replacing the characters right there in the datastore. Do not use Java for this.
If you're actually using the "command prompt" as user interface, then you're actually lost. It doesn't support UTF-8. As suggested in the comments and in the article linked in the comments, you need to create a Swing application instead of relying on the restricted command prompt environment.
You can specify encoding when establishing connection. This way was perfect and solve my encoding problem:
DatabaseImpl open = DatabaseImpl.open(new File("main.mdb"), true, null, Database.DEFAULT_AUTO_SYNC, java.nio.charset.Charset.availableCharsets().get("windows-1251"), null, null);
Table table = open.getTable("FolderInfo");
Using "ISO-8859-1" helped me deal with the French charactes.

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