[java] Where to get "UTF-8" string literal in Java?

I'm trying to use a constant instead of a string literal in this piece of code:

new InputStreamReader(new FileInputStream(file), "UTF-8")

"UTF-8" appears in the code rather often, and would be much better to refer to some static final variable instead. Do you know where I can find such a variable in JDK?

BTW, on a second thought, such constants are bad design: Public Static Literals ... Are Not a Solution for Data Duplication

In case this page comes up in someones web search, as of Java 1.7 you can now use java.nio.charset.StandardCharsets to get access to constant definitions of standard charsets.

Now I use org.apache.commons.lang3.CharEncoding.UTF_8 constant from commons-lang.

The Google Guava library (which I'd highly recommend anyway, if you're doing work in Java) has a Charsets class with static fields like Charsets.UTF_8, Charsets.UTF_16, etc.

Since Java 7 you should just use java.nio.charset.StandardCharsets instead for comparable constants.

Note that these constants aren't strings, they're actual Charset instances. All standard APIs that take a charset name also have an overload that take a Charset object which you should use instead.

This constant is available (among others as: UTF-16, US-ASCII, etc.) in the class org.apache.commons.codec.CharEncoding as well.

In Java 1.7+

Do not use "UTF-8" string, instead use Charset type parameter:

import java.nio.charset.StandardCharsets

...

new InputStreamReader(new FileInputStream(file), StandardCharsets.UTF_8);

If you are using OkHttp for Java/Android you can use the following constant:

import com.squareup.okhttp.internal.Util;

Util.UTF_8; // Charset
Util.UTF_8.name(); // String

Class org.apache.commons.lang3.CharEncoding.UTF_8 is deprecated after Java 7 introduced java.nio.charset.StandardCharsets

• @see JRE character encoding names
• @since 2.1
• @deprecated Java 7 introduced {@link java.nio.charset.StandardCharsets}, which defines these constants as
• {@link Charset} objects. Use {@link Charset#name()} to get the string values provided in this class.
• This class will be removed in a future release.

Constant definitions for the standard. These charsets are guaranteed to be available on every implementation of the Java platform. since 1.7

 package java.nio.charset;
 Charset utf8 = StandardCharsets.UTF_8;

There are none (at least in the standard Java library). Character sets vary from platform to platform so there isn't a standard list of them in Java.

There are some 3rd party libraries which contain these constants though. One of these is Guava (Google core libraries): http://guava-libraries.googlecode.com/svn/trunk/javadoc/com/google/common/base/Charsets.html

You can use Charset.defaultCharset() API or file.encoding property.

But if you want your own constant, you'll need to define it yourself.