Maven default locale not same with OS locale

Question

When I type

mvn --version

in command prompt I see:

Default Locale : en_US

However my System Locale is tr_TR

When I start a Java SE Project without maven and run Locale.getDefault() tr_TR returns fine. But when I run a Maven project and then Locale.getDefault() it returns en_US which I do not like.

How can I tell maven that my default locale is TR ?

Answer 1

You can use this command

set MAVEN_OPTS= -Duser.language=tr

Anyway the best solution is to put these informations in the POM file and never by command line. In particular you have to deal with the configuration of Maven-Surefire-Plugin

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.9</version>
        <configuration>
            <systemPropertyVariables>
                <user.language>tr</user.language>
                <user.region>TR</user.region>
            </systemPropertyVariables>
        </configuration> 
    </plugin>

Second Question: Another question if I may, I am running a web app in my locale but it supports lets say german, english.. And your system locale is DE. Can I get your system locale from your request? Or maybe the language you prefer by your browser?

You can take these informations from the request. Here is an example in a servlet.

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.Locale;

public class GetLocale extends HttpServlet{

  public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException, IOException
  {
      Locale locale = request.getLocale();
      String language = locale.getLanguage();
      String country = locale.getCountry();

      response.setContentType("text/html");
      PrintWriter out = response.getWriter();

      out.println(language + ":" + country);
  }
}

Answer 2

You can also use

<properties>
    <argLine>-Duser.language=tr</argLine>
</properties>

This case works better when the argument is needed at the start of the JVM, as using maven-surefire-plugin, your JVM is already running and the arguments won't be reloaded (that was my case using some initialization with @RunWith(SpringRunner.class) and @SpringBootTest to initialize a MockMvc).