Spring MVC UTF-8 Encoding

Ok guys I found the reason for my encoding issue.

The fault was in my build process. I didn't tell Maven in my pom.xml file to build the project with the UTF-8 encoding. Therefor Maven just took the default encoding from my system which is MacRoman and build it with the MacRoman encoding.

Luckily Maven is warning you about this when building your project (BUT there is a good chance that the warning disappears to fast from your screen because of all the other messages).

Here is the property you need to set in the pom.xml file:

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    ...
</properties>

Thank you guys for all your help. Without you guys I wouldn't be able to figure this out!


In addition to Benjamin's answer (which I've only skimmed), you need to make sure that your files are actually stored using the proper encoding (that would be UTF-8 for source code, JSPs etc., but note that Java Properties files must be encoded as ISO 8859-1 by definition).

The problem with this is that it's not possible to tell what encoding has been used to store a file. Your only option is to open the file using a specific encoding, and checking whether or not the content makes sense. You can also try to convert the file from the assumed encoding to the desired encoding using iconv - if that produces an error, your assumption was incorrect. So if you assume that hello.jsp is encoded as UTF-8, run "iconv -f UTF-16 -t UTF-8 hello.jsp" and check for errors.

If you should find out that your files are not properly encoded, you need to find out why. It's probably the editor or IDE you used to create the file. In case of Eclipse (and STS), make sure the Text File Encoding (Preferences / General / Workspace) is set to UTF-8 (it unfortunately defaults to your system's platform encoding).

What makes encoding problems so difficult to debug is that there's so many components involved (text editor, borwser, plus each and every software component in between, in some cases including a database), and each of them has the potential to introduce an error.


Make sure you register Spring's CharacterEncodingFilter in your web.xml (must be the first filter in that file).

<filter>  
    <filter-name>encodingFilter</filter-name>  
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>  
    <init-param>  
       <param-name>encoding</param-name>  
       <param-value>UTF-8</param-value>  
    </init-param>  
    <init-param>  
       <param-name>forceEncoding</param-name>  
       <param-value>true</param-value>  
    </init-param>  
</filter>  
<filter-mapping>  
    <filter-name>encodingFilter</filter-name>  
    <url-pattern>/*</url-pattern>  
</filter-mapping>

If you are on Tomcat you might not have set the URIEncoding in your server.xml. If you don't set it to UTF-8 it won't work. Definitely keep the CharacterEncodingFilter. Nevertheless, here's a concise checklist to follow. It will definitely guide you to make this work.


In addition to Benjamin's answer - in case if you are using Spring Security, placing the CharacterEncodingFilter in web.xml might not always work. In this case you need to create a custom filter and add it to the filter chain as the first filter. To make sure it's the first filter in the chain, you need to add it before ChannelProcessingFilter, using addFilterBefore in your WebSecurityConfigurerAdapter:

@Configuration
@EnableWebSecurity 
public class SecurityConfig extends WebSecurityConfigurerAdapter {


    @Override
    protected void configure(HttpSecurity http) throws Exception {

        //add your custom encoding filter as the first filter in the chain
        http.addFilterBefore(new EncodingFilter(), ChannelProcessingFilter.class);

        http.authorizeRequests()
            .and()
            // your code here ...
    }
}

The ordering of all filters in Spring Security is available here: HttpSecurityBuilder - addFilter()

Your custom UTF-8 encoding filter can look like following:

public class EncodingFilter extends GenericFilterBean {

    @Override
    public void doFilter(
            ServletRequest request, 
            ServletResponse response,
            FilterChain chain) throws IOException, ServletException {

        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");

        chain.doFilter(request, response);
    }
}

Don't forget to add in your jsp files:

<%@ page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8" %>

And remove the CharacterEncodingFilter from web.xml if it's there.

Tags:

Java

Character Encoding

Utf 8

Spring Mvc

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