spring boot web polish characters encoding problem

Question

In Spring Boot 2.6.0 java 8 application configuration class has content:

@Configuration
public class Internationalization implements WebMvcConfigurer {
 // localeResolver, localeChangeInterceptor, addInterceptors
 @Bean
 public ResourceBundleMessageSource messageSource() {
 ResourceBundleMessageSource messageSource
 = new ResourceBundleMessageSource();
 messageSource.setBasename("lang/messages");
 messageSource.setDefaultEncoding("ISO-8859-2");
 return messageSource;
 }
}

messages_pl.properties content

lang.change=Zmiana języka
switch.en=Przełącz na angielski
switch.pl=Przełącz na polski
pick.date=Wybierz rok i miesiąc
main.header=Nagłówek głównej strony

on the web page with ?lang=pl parameter and <meta charset="ISO-8859-2"> is presented with thymeleaf :

Nag?ówek g?ównej strony

Wybierz rok i miesi?c

Zmiana j?zyka: Prze??cz na angielski Prze??cz na polski

enter image description here

change to UTF-8 change doesn't help

Nag?�wek g?�wnej strony

Wybierz rok i miesi?c

Zmiana j?zyka: Prze??cz na angielski Prze??cz na polski

• g00se: Nag?ówek g?ównej strony looks more like a font problem. Have you got a font installed to show the required glyphs?
• haoz: I have not any font installed in Spring Boot java application. Html body has font-family: Tahoma, Verdana, sans-serif;
• haoz: All set to UTF-8 and added Polish Font: Lato to css acc. to: stackoverflow.com/questions/73161327/… , but still no Polish characters on the page.
• g00se: Are you using the same browser to view your own code output as the one you're viewing this question with? If yes, how does your posting of messages_pl.properties look?
• haoz: I've tested by Chrome and Firefox, as well. Build is performed by InteliJ.

Answer 1

spring.messages.basename=lang/messages
spring.messages.encoding=UTF-8
spring.mvc.locale-resolver=accept-header

try adding these, let spring boot handle the configuration automatically

also, i suggest to prevent using iso encoding since most browser doesnt support or kind of overrides this. Going with UTF-8 is much better as it does what ISO does (correct me if im wrong)

• haoz: maybe web.locale-resolver: accept_header ?
• I Am Staple: this could do, it will automatically modifies the language or any headers based on the client's preferences. docs.spring.io/spring-framework/reference/web/webmvc/… but downside of this is, you cant change the language through url, that's if you have a setting where users can change language or any preferences on your system. But with that property, it's automatic which is good too
• haoz: still no Polish characters :(
• I Am Staple: i see can you look at your current browser settings, may it be on your browser or operating system if your preferred language is polish? because this setting depends on the user's preferred language setting