How to change language at runtime in java swing

Question

I try to change the Locale at runtime in my swing application.
But I can't figure out how it supposed to work, or there are no master plan?

I can only think of two choices:
1. Restart the application, not the best user experience.
2. Create a localization manager that can register/unregister components, on a change it just iterate all components and change the text.

Both 1 and 2 feels awkward.

Other info:
For the moment the orientation is not a target.
The application is obfuscated.

Example:

LocRes_en.properties:


    text1 = English text

LocRes_ja.properties


    text1 = Japanese text

ChangeLocale.java:


    import java.awt.EventQueue;
    import java.awt.FlowLayout;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.util.Locale;
    import java.util.ResourceBundle;

    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;

    public class ChangeLocale {

        private JFrame frame;

        public static void main(String[] args) {
            EventQueue.invokeLater(new Runnable() {
                public void run() {
                    try {
                        ChangeLocale window = new ChangeLocale();
                        window.frame.setVisible(true);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            });
        }

        public ChangeLocale() {
            initialize();
        }

        private void initialize() {
            frame = new JFrame();
            frame.setBounds(100, 100, 450, 300);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            FlowLayout flowLayout = new FlowLayout(FlowLayout.CENTER, 5, 5);
            frame.getContentPane().setLayout(flowLayout);

            JButton btnChangeLoc = new JButton("Change Locale");
            frame.getContentPane().add(btnChangeLoc);

            final JLabel lblLabel1 = new JLabel("New label");
            frame.getContentPane().add(lblLabel1);
            Locale.setDefault(new Locale("en"));
            ResourceBundle r = ResourceBundle.getBundle("LocRes");
            lblLabel1.setText(r.getString("text1"));

            btnChangeLoc.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    Locale.setDefault(new Locale("ja"));
                    ResourceBundle r = ResourceBundle.getBundle("LocRes");
                    // Manually iterate through all components :(
                    lblLabel1.setText(r.getString("text1"));
                    //
                }
            });
        }
    }

never needed that, but there are must be some examples about loading properties to the HashMap or List — mKorbel

flash flash · Accepted Answer · 2012-10-31T06:43:57

I've implemented this with ResourceBundles and an EventBus.

When the locale is changed, the EventBus fires an localeChangedEvent. All JFrame windows which have localized strings then have to subscribe to this event. They must also implement a changeLocale() method which is executed when the event is received.

In this method all strings will be updated to the current locale.

public void changeLocale(ResourceBundle rb) {
    lblLabel1.setText(rb.getString("text1"));
    lblLabel2.setText(rb.getString("text2"));
    ...
}

How to change language at runtime in java swing

4 Answers