Prepare a Java Source File for Localization

public FormValidation doCheckName(@QueryParameter String value)
        throws IOException, ServletException {
    if (value.length() == 0)
        return FormValidation.error("Please set a name"); (1)
    if (value.length() < 4)
        return FormValidation.warning("Isn't the name too short?"); (2)
    return FormValidation.ok();
}

...

/**
 * This human readable name is used in the configuration screen.
 */
public String getDisplayName() {
    return "Say hello world"; (3)
}

@Override
public boolean configure(StaplerRequest req, JSONObject formData) throws FormException {
    // To persist global configuration information,
    // set that to properties and call save().
    useFrench = formData.getBoolean("useFrench"); (4)
    // ^Can also use req.bindJSON(this, formData);
    //  (easier when there are many fields; need set* methods for this, like setUseFrench)
    save();
    return super.configure(req,formData);
}

HelloWorldBuilder.NoName=Please set a name (1)
HelloWorldBuilder.ShortName=\(2)
  Isn''t the name too short? (3)
# Unicode variant of the line above: (4)
# Isn\u2019t the name too short? (5)
HelloWorldBuilder.DisplayName=Say hello world

public FormValidation doCheckName(@QueryParameter String value)
        throws IOException, ServletException {
    if (value.length() == 0)
        return FormValidation.error(Messages.HelloWorldBuilder_NoName());
    if (value.length() < 4)
        return FormValidation.warning(Messages.HelloWorldBuilder_ShortName());
    return FormValidation.ok();
}