JUnit Rule which allows to use specific locale for particular tests.

LocaleRule.java

import java.util.Locale;

/**
 * Rule allows to use specific locale for particular tests.
 * 
 * Default locale is stored before test and restored after.
 * Rule can be used on the method or class level. 
 * 
 * @author setkomac
 *
 */
public class LocaleRule extends InitializationRule {

    	private static final Locale defaultLocale = Locale.getDefault();
	private Locale locale;

	/**
	 * Object constructor.
	 * @param locale Local that will be used inside test.
	 */
	public LocaleRule(Locale locale){
		this.locale = locale;
	}

	@Override
	public void before() {
		Locale.setDefault(locale);
	}

	@Override
	public void after() {
		Locale.setDefault(defaultLocale);
	}

}

MyLocaleRule.java

import java.util.Locale;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;

public class MyLocaleRule implements TestRule {

	private static final Locale defaultLocale = Locale.getDefault();
	private final Locale locale;
	
	public MyLocaleRule(Locale locale) {
		this.locale = locale;
	}

	@Override
	public Statement apply(final Statement base, Description description) {
		return new Statement() {
			@Override
			public void evaluate() throws Throwable {
				Locale.setDefault(locale);
				try {
					base.evaluate();
				} catch (Throwable t) {
					throw t;
				} finally {
					Locale.setDefault(defaultLocale);
				}
			}
		};
	}

}

MyLocaleRuleUsingExternalResource.java

import java.util.Locale;
import org.junit.rules.ExternalResource;

public class MyLocaleRuleUsingExternalResource extends ExternalResource {

	private static final Locale defaultLocale = Locale.getDefault();
	private final Locale locale;
	
	public MyLocaleRuleUsingExternalResource(Locale locale) {
		this.locale = locale;
	}
	
	@Override
	protected void before() throws Throwable {
		Locale.setDefault(locale);
	}
	
	@Override
	protected void after() {
		Locale.setDefault(defaultLocale);
	}

}

This code was obtained from https://github.com/msetkowski/rules/blob/master/src/main/java/org/wowbagger/rules/LocaleRule.java

https://github.com/AlistairIsrael/junit-rules