Develop Reference

Java with maven, netbeans

I'm currently developing a proyect about chess. Main idea is to use it on console as CMD.
It currently works with array[8][8], i store the "chess pieces" on it. But the main problem is:
When i want to print an emoji as "♜, ♞, ♝, and so on", output displays the emojis as ?.
I have already tried some things like UTF-8, Emoji-Java library, changing the Fonts of output console with compatible Fonts... I've tried for hours, i have searched around the internet, i can't find anything... If you help me i'd appreciate it.
[?][?][?][?][?][?][?][?]//♜, ♞, ♝, ♛, ♚, ♝, ♞, ♜.
[null][null][null][null][null][null][null][null]//Null= available space to move
[null][null][null][null][null][null][null][null]
[null][null][null][null][null][null][null][null]
[null][null][null][null][null][null][null][null]
[null][null][null][null][null][null][null][null]
[null][null][null][null][null][null][null][null]
[null][null][null][null][null][null][null][null]
//Please ignore the null values, it's going to be fixed when the problem is solved...

It's complicated, very complicated, and it differs by the OS and it also differs by the version (windows 7 vs 10), and it differs by the patch level (eg windows 10 before and after patch 2004 for example).
So let me save you hours of further heartache by suggesting that you use a UI instead where you can control the underlying character set. For example, using Swing or JavaFX.
However, if you insist on using the console then you need to take a number of steps.
The first being to use a PrintWriter in your code to write out characters using the correct encoding:
PrintWriter consoleOut = new PrintWriter(new OutputStreamWriter(System.out, StandardCharsets.UTF_8));
consoleOut.println("your character here");
The next step is to pre-configure the console to use your character set. For example in windows you might use the chcp command before starting your jar file:
chcp 65001
java -jar .....
But not only that, you should use the Dfile.encoding flag when you start your jar:
java -Dfile.encoding=UTF-8 -jar yourChessApplciation.jar
Now assuming you got all those steps right it might work, but it might not. You also need to ensure that all your source files are encoded in UTF-8. I won't go into that here because it differs by this IDE, but if you are using something like Netbeans then you can configure the source encoding in the project properties.
I would also encourage you to use the Unicode character definition rather than the actual symbol in your code:
//Avoid this, it may fail for a number of reasons (mostly encoding related)
consoleOut.println("♜");
//The better way to write the character using the unicode definition
consoleOut.println("\u265C");
Now even with all this you still need to ensure that your chosen console uses the correct character set. Here are the steps to follow for powershell: Using UTF-8 Encoding (CHCP 65001) in Command Prompt / Windows Powershell (Windows 10) Or for windows cmd you can take a look here: How to make Unicode charset in cmd.exe by default
So with all of those steps completed you can compile this code:
PrintWriter consoleOut = new PrintWriter(new OutputStreamWriter(System.out, StandardCharsets.UTF_8));
consoleOut.println("Using UTF_8 output with the character: ♜");
consoleOut.println("Using UTF_8 output with the unicode definition: \u265C");
consoleOut.close();
And then run your compiled jar file in your console (Powershell in this example) something like this (You wont need to use chcp 65001 if you configured the powershell console correctly):
chcp 65001
java -Dfile.encoding=UTF-8 -jar yourChessApplciation.jar
And the output should give the following result:
Using UTF_8 output with the character: ♜
Using UTF_8 output with the unicode definition: ♜
But it might still fail to show correctly, in which case see my opening section about using a UI, or try a different console... It's complicated.

ant build failed error: unmappable character for encoding UTF8

Have an ant build script which builds some java files. These files may have existed in a windows environment previously, though I am attempting to build and compile them on OSX. The file in question seems to be encoded with the following
u'Western (Windows 1252)'
The error I receive is
error: unmappable character for encoding UTF8
Does anyone have experience rectifying these types of issues?

Open the file with a text editor that allows good control over coding, such as Emacs, and save the file in UTF-8.

Java difference between running from netbeans and cmd

I have a program that writes text data to files. When I run it from netbeans the files are in a correct encoding and you can read them with a notepad. When I run it from cmd using java -cp ....jar the encoding is different.
What may be the issue??
ps. I've checked that the jre. versions are the same that executes (v 1.8.0_31)

Netbeans startup scripts may specify a different encoding than your system default. You can check in your netbeans.conf.
You can set the file.encoding property when invoking java. For example, java -Dfile.encoding=UTF8 -cp... jar.
If you do not want to be surprised when running your code on different environments, even better solution would be to specify the encoding in your source code.
Further reading:
file encoding: Character and Byte Streams
netbeans.conf encoding options: How To Display UTF8 In Netbeans 7?

Eclipse wrong Java properties UTF-8 encoding

I have a JavaEE project, in which I use message properties files. The encoding of those file is set to UTF-8. In the file I use the german umlauts like ä, ö, ü. The problem is, sometimes those characters are replaced with unicode like \uFFFD\uFFFD, but not for every character. Now, I have a case where ä and ü are both replaced with \uFFFD\uFFFD, but not for every occurring of ä and ü.
The Git diff shows me something like this:
mail.adresses=E-Mail hinzufügen:
-mail.adresses.multiple=E-Mails durch Kommata getrennt hinzufügen.
+mail.adresses.multiple=E-Mails durch Kommata getrennt hinzuf\uFFFD\uFFFDgen.
mail.title=Einladungs-E-Mail
box.preview=Vorschau
box.share.text=Sie können jetzt die ausgewählten Bilder mit Ihren Freunden teilen.
## -6880,7 +6880,7 ## browser.cancel=Abbrechen
browser.selectImage=übernehmen
browser.starImage=merken
browser.removeImage=Löschen
-browser.searchForSimilarImages=ähnliche
+browser.searchForSimilarImages=\uFFFD\uFFFDhnliche
browser.clear_drop_box=löschen
Also, there are lines changed, which I have not touched. I don't understand why I get such a behavior. What could be the cause for the above problem?
My system:
Antergos / Arch Linux
System encoding UTF-8
Python 3.5.0 (default, Sep 20 2015, 11:28:25)
[GCC 5.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.getdefaultencoding()
'utf-8'
Eclipse Mars 1
Text file encoding UTF-8
Properties file encoding UTF-8
Tomcat 8
Java JDK 8
If I use another Editor like Atom to edit those message properties files, I don't ran into this problem.
I also realized in a case, if I copy the original value browser.searchForSimilarImages=ähnliche from Git diff and replace the wrong value browser.searchForSimilarImages=\uFFFD\uFFFDhnliche in Eclipse with that, then I have the correct umlauts in the message properties file.

Root cause:
By default ISO 8859-1 character encoding is used for Eclipse properties file (read here), so if the file contains any character beyond ISO 8859-1 then it will not be processed as expected.
Solution 1
If you use Eclipse then you will notice that it implicitly converts the special character into \uXXXX equivalent. Try copying
会意字 / 會意字
into a properties file opened in Eclipse.
EDIT: As per comment from OP
Update the encoding of your Eclipse as shown below. If you set encoding as UTF-32 then even you can see Chinese character, which you cannot see generally.
How to change Encoding of properties file in Eclipse: See this Eclipse Bugzilla bug for more details, which talks about several other possibilities and in the end suggest what I have highlighted below.
Chinese characters can be seen in Eclipse after encoding is set properly:
Solution 2
If above doesn't work consistently for you (it does work for me and I never see encoding issues) then try this using some Eclipse plugin which handles encoding of properties or other files. For example Eclipse ResourceBundle Editor or Extended Resource-Bundle editor
I would recommend using Eclipse ResourceBundle Editor.
Solution 3
Another possibility to change encoding of file is using Edit --> Set Encoding option. It really matters because it changes the default character set and file encoding. Play around with by changing encoding using Edit --> Set Encoding option and do following Java sysout System.out.println("Default Charset=" + Charset.defaultCharset()); and System.out.println(System.getProperty("file.encoding"));
As an aside: 1
Process the properties file to have content with ISO 8859-1 character encoding by using native2ascii - Native-to-ASCII Converter
What native2ascii does: It converts all the non-ISO 8859-1 character in their equivalent \uXXXX. This is a good tool because you need not to search the \uXXXX equivalent of special character.
Usage for UTF-8: native2ascii -encoding utf8 e:\a.txt e:\b.txt
As an aside: 2
Every computer program whether an IDE, application server, web server, browser, etc. understands only bits, so it need to know how to interpret the bits to make expected sense out of it because depending upon encoding used, same bits can represent different characters. And that's where "Encoding" comes into picture by giving a unique identifier to represent a character so that all computer programs, diverse OS etc. knows exact right way to interpret it.
So, if you have written into a file using some encoding scheme, lets say UTF-8, and then reading using any editor but running with encoding scheme as UTF-8 then you can expect to get correct display.
Please do read my this answer to get more details but from browser-server perspective.

Add the following arguments to your eclipse.ini file.
-Dclient.encoding.override=UTF-8
-Dfile.encoding=UTF-8
By default Eclipse uses the encoding format picked up by the Java Virtual Machine (JVM). Also, you can set the file encoding to utf-8.

Resolved by doing the below changes :
Modified below properties in eclipse.ini and close and start the eclipse applications
-Dclient.encoding.override=UTF-8
-Dfile.encoding=UTF-8
Set the encoding to the UTF-8 [Navigation path : Edit -> Set encoding]

Properties Files are expected to be ISO-8859-1 (Latin-1) encoded.
Most likely this what eclipse was set to by default as well.
You have to make sure that every tool which is run in the build or whatever disregards the spec and uses UTF-8 instead.

This looks like a mixture of Eclipse and git encoding or rather not-encoding.
Git uses raw bytes and doesn't care about encoding. Using git diff you might get characters like shown here. An example there is R<C3><BC>ckg<C3><A4>ngig # should be "Rückgängig".
As you can see there's two funny bracket things showing per umlaut. And in your editor, there are always two \uFFFD for each umlaut in the lines starting with +.
So I assume that your UTF-8 editor tries to interpret the git notation and fails. This in turn leads to the representation \uFFFD, which basically meands that this is character whose value is unknown or unrepresentable (see here).
Like suggested in the first link, you can try setting LESSCHARSET=UTF-8 in your environment variable (Windows). Hmm, in Linux it should be in etc/profile ?

see: a marker such as FFFD (REPLACEMENT CHARACTER) in http://unicode.org/faq/utf_bom.html
and see native2ascii --help
-encoding encoding_name
Specifies the name of the character encoding to be used by the conversion procedure. If this option is not present, then the
default character encoding (as determined by the java.nio.charset.Charset.defaultCharset method) is used. The encoding_name
string must be the name of a character encoding that is supported by the JRE. See Supported Encodings at
http://docs.oracle.com/javase/8/docs/technotes/guides/intl/encoding.doc.html
a case
$ file yourfile.properties
yourfile.properties : ISO-8859 text, with very long lines
$ native2ascii -encoding ISO-8859-1 yourfile.properties yourfile.properties

Java source file encoding with Chinese character

I import a Java project from Windows platform to Ubuntu.
My Ubuntu is 10.10, Gnome environment: My LANGUAGE is set to en_US:en
My terminal's character encoding is: Unicode (UTF-8)
My IDE is eclipse and text file encoding is: GBK.
In source file, there are some Chinese constant character.
The project build successful on Windows with ant,
but on Ubuntu, I get compile error:
illegal character: \65533
I don't want to use \uxxxx format as the file is already there,
And I've tried the -encoding option for javac, but still can't compile.

I think the problem lies not with Ubuntu, Ubuntu's console, Javac or Eclipse but with the way you transfer the file from windows to Ubuntu. You have to store it as utf-8 before you copy it to Ubuntu otherwise the codepoint-information that is set in your Windows your locale is already lost.

Did you specify the encoding option of the <javac> task in your build.xml?
It should look like this:
<javac encoding="GBK" ...>
If you haven't specified it, then on Windows it will use the platform default encoding (which is GBK in your setup) and on Linux it will use the platform default encoding (which is UTF-8 in your setup).
Since you want the build to work on both platforms (preferably without changing the configuration of either platform), you need to specify the encoding when you compile.

You need to convert you source codes from you windows codepage to UTF-8. Use iconv for this.