379
votes

How do I properly set the default character encoding used by the JVM (1.5.x) programmatically?

I have read that -Dfile.encoding=whatever used to be the way to go for older JVMs. I don't have that luxury for reasons I wont get into.

I have tried:

System.setProperty("file.encoding", "UTF-8");

And the property gets set, but it doesn't seem to cause the final getBytes call below to use UTF8:

System.setProperty("file.encoding", "UTF-8");

byte inbytes[] = new byte[1024];

FileInputStream fis = new FileInputStream("response.txt");
fis.read(inbytes);
FileOutputStream fos = new FileOutputStream("response-2.txt");
String in = new String(inbytes, "UTF8");
fos.write(in.getBytes());
17
Excellent comments guys - and things I was already thinking myself. Unfortunately there is an underlying String.getBytes() call that I have no control over. The only way I currently see to get around it is to set the default encoding programmatically. Any other suggestions?Scott T
maybe irrelevant question but, is there difference when UTF8 is set with "UTF8", "UTF-8" or "utf8". Recently I found that IBM WAS 6.1 EJB and WEB containers differently treats (in way of case-sensitivity) strings used to define encoding.igor.beslic
Just a detail but: prefer UTF-8 to UTF8 (only the former is standard). This still applies in 2012...Christophe Roussy
Setting or reading the file.encoding property is not supported.McDowell
@erickson Am still not clear with the query, Is it not true that, "file.encoding" is relevant when character based I/O streams are used(all subclasses of class Reader & class Writer)? Because class FileInputStream is byte based I/O stream, so why one should care about character set in byte-based I/O stream?overexchange

17 Answers

334
votes

Unfortunately, the file.encoding property has to be specified as the JVM starts up; by the time your main method is entered, the character encoding used by String.getBytes() and the default constructors of InputStreamReader and OutputStreamWriter has been permanently cached.

As Edward Grech points out, in a special case like this, the environment variable JAVA_TOOL_OPTIONS can be used to specify this property, but it's normally done like this:

java -Dfile.encoding=UTF-8 … com.x.Main

Charset.defaultCharset() will reflect changes to the file.encoding property, but most of the code in the core Java libraries that need to determine the default character encoding do not use this mechanism.

When you are encoding or decoding, you can query the file.encoding property or Charset.defaultCharset() to find the current default encoding, and use the appropriate method or constructor overload to specify it.

177
votes

From the JVM™ Tool Interface documentation…

Since the command-line cannot always be accessed or modified, for example in embedded VMs or simply VMs launched deep within scripts, a JAVA_TOOL_OPTIONS variable is provided so that agents may be launched in these cases.

By setting the (Windows) environment variable JAVA_TOOL_OPTIONS to -Dfile.encoding=UTF8, the (Java) System property will be set automatically every time a JVM is started. You will know that the parameter has been picked up because the following message will be posted to System.err:

Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF8

72
votes

I have a hacky way that definitely works!!

System.setProperty("file.encoding","UTF-8");
Field charset = Charset.class.getDeclaredField("defaultCharset");
charset.setAccessible(true);
charset.set(null,null);

This way you are going to trick JVM which would think that charset is not set and make it to set it again to UTF-8, on runtime!

39
votes

I think a better approach than setting the platform's default character set, especially as you seem to have restrictions on affecting the application deployment, let alone the platform, is to call the much safer String.getBytes("charsetName"). That way your application is not dependent on things beyond its control.

I personally feel that String.getBytes() should be deprecated, as it has caused serious problems in a number of cases I have seen, where the developer did not account for the default charset possibly changing.

19
votes

I can't answer your original question but I would like to offer you some advice -- don't depend on the JVM's default encoding. It's always best to explicitly specify the desired encoding (i.e. "UTF-8") in your code. That way, you know it will work even across different systems and JVM configurations.

12
votes

Try this :

    new OutputStreamWriter( new FileOutputStream("Your_file_fullpath" ),Charset.forName("UTF8"))
7
votes

I have tried a lot of things, but the sample code here works perfect. Link

The crux of the code is:

String s = "एक गाव में एक किसान";
String out = new String(s.getBytes("UTF-8"), "ISO-8859-1");
6
votes

In case you are using Spring Boot and want to pass the argument file.encoding in JVM you have to run it like that:

mvn spring-boot:run -Drun.jvmArguments="-Dfile.encoding=UTF-8"

this was needed for us since we were using JTwig templates and the operating system had ANSI_X3.4-1968 that we found out through System.out.println(System.getProperty("file.encoding"));

Hope this helps someone!

6
votes

We were having the same issues. We methodically tried several suggestions from this article (and others) to no avail. We also tried adding the -Dfile.encoding=UTF8 and nothing seemed to be working.

For people that are having this issue, the following article finally helped us track down describes how the locale setting can break unicode/UTF-8 in Java/Tomcat

http://www.jvmhost.com/articles/locale-breaks-unicode-utf-8-java-tomcat

Setting the locale correctly in the ~/.bashrc file worked for us.

2
votes

I'm using Amazon (AWS) Elastic Beanstalk and successfully changed it to UTF-8.

In Elastic Beanstalk, go to Configuration > Software, "Environment properties". Add (name) JAVA_TOOL_OPTIONS with (value) -Dfile.encoding=UTF8

After saving, the environment will restart with the UTF-8 encoding.

2
votes

Solve this problem in my project. Hope it helps someone.

I use LIBGDX java framework and also had this issue in my android studio project. In Mac OS encoding is correct, but in Windows 10 special characters and symbols and also russian characters show as questions like: ????? and other incorrect symbols.

  1. Change in android studio project settings: File->Settings...->Editor-> File Encodings to UTF-8 in all three fields (Global Encoding, Project Encoding and Default below).

  2. In any java file set:

    System.setProperty("file.encoding","UTF-8");

  3. And for test print debug log:

    System.out.println("My project encoding is : "+ Charset.defaultCharset());

1
votes

Not clear on what you do and don't have control over at this point. If you can interpose a different OutputStream class on the destination file, you could use a subtype of OutputStream which converts Strings to bytes under a charset you define, say UTF-8 by default. If modified UTF-8 is suffcient for your needs, you can use DataOutputStream.writeUTF(String):

byte inbytes[] = new byte[1024];
FileInputStream fis = new FileInputStream("response.txt");
fis.read(inbytes);
String in = new String(inbytes, "UTF8");
DataOutputStream out = new DataOutputStream(new FileOutputStream("response-2.txt"));
out.writeUTF(in); // no getBytes() here

If this approach is not feasible, it may help if you clarify here exactly what you can and can't control in terms of data flow and execution environment (though I know that's sometimes easier said than determined). Good luck.

1
votes
mvn clean install -Dfile.encoding=UTF-8 -Dmaven.repo.local=/path-to-m2

command worked with exec-maven-plugin to resolve following error while configuring a jenkins task.

Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=512m; support was removed in 8.0
Error occurred during initialization of VM
java.nio.charset.IllegalCharsetNameException: "UTF-8"
    at java.nio.charset.Charset.checkName(Charset.java:315)
    at java.nio.charset.Charset.lookup2(Charset.java:484)
    at java.nio.charset.Charset.lookup(Charset.java:464)
    at java.nio.charset.Charset.defaultCharset(Charset.java:609)
    at sun.nio.cs.StreamEncoder.forOutputStreamWriter(StreamEncoder.java:56)
    at java.io.OutputStreamWriter.<init>(OutputStreamWriter.java:111)
    at java.io.PrintStream.<init>(PrintStream.java:104)
    at java.io.PrintStream.<init>(PrintStream.java:151)
    at java.lang.System.newPrintStream(System.java:1148)
    at java.lang.System.initializeSystemClass(System.java:1192)
0
votes

We set there two system properties together and it makes the system take everything into utf8

file.encoding=UTF8
client.encoding.override=UTF-8
0
votes

Following @Caspar comment on accepted answer, the preferred way to fix this according to Sun is :

"change the locale of the underlying platform before starting your Java program."

http://bugs.java.com/view_bug.do?bug_id=4163515

For docker see:

http://jaredmarkell.com/docker-and-locales/

0
votes

Recently I bumped into a local company's Notes 6.5 system and found out the webmail would show unidentifiable characters on a non-Zhongwen localed Windows installation. Have dug for several weeks online, figured it out just few minutes ago:

In Java properties, add the following string to Runtime Parameters

-Dfile.encoding=MS950 -Duser.language=zh -Duser.country=TW -Dsun.jnu.encoding=MS950

UTF-8 setting would not work in this case.

0
votes

My team encountered the same issue in machines with Windows.. then managed to resolve it in two ways:

a) Set enviroment variable (even in Windows system preferences)

JAVA_TOOL_OPTIONS
-Dfile.encoding=UTF8

b) Introduce following snippet to your pom.xml:

 -Dfile.encoding=UTF-8 

WITHIN

 <jvmArguments>
 -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8001
 -Dfile.encoding=UTF-8
 </jvmArguments>