Servlet encoding globally using maven + guice

Question

In my project, I'm using Maven + Google Guice + Java 8, and I checked that my webpage responses were not encoded and the problem is from the backend side.

The solution I found to fix it was to update the HttpServletResponse:

@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
...
resp.setContentType("text/html; charset=UTF-8");
resp.setCharacterEncoding("UTF-8");
}

But I would like to configure it globally and not only for one Servlet, to do it I tried what they explained here adding encoding to the pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>YOUR_COMPANY</groupId>
    <artifactId>YOUR_APP</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <properties>
        <project.java.version>1.8</project.java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>

    <dependencies>
        <!-- Your dependencies -->
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <source>${project.java.version}</source>
                    <target>${project.java.version}</target>
                    <encoding>${project.build.sourceEncoding}</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>3.0.2</version>
                <configuration>
                    <encoding>${project.build.sourceEncoding}</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

But it didn't work. Could someone help with it? Configuring it globally in my project?

The maven configuration only affects how strings present in your source code are read and written into the class files. You can't configure a servlet response encoding this way. — Robert, Jul 05 '21 at 12:26
May be in the used J2EE server. For setting a header globally see also https://stackoverflow.com/q/1676953/150978 — Robert, Jul 05 '21 at 12:33

score 0 · Accepted Answer · answered Jul 05 '21 at 13:18

Firstly, thank you @Robert for your answer and help.

As he pointed out:

The maven configuration only affects how strings present in your source code are read and written into the class files. You can't configure a servlet response encoding this way.

To solve it using Guice, we need to create a filter in our ServletModule as we can find in the documentation.

I did it adding the filter to configureServlets():

filter("/*").through(createServletFilter());

And the filter create was:

protected Filter createServletFilter() {
 return new Filter() {
   @Override
   public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
       throws IOException, ServletException {
     response.setContentType("text/html; charset=UTF-8");
     response.setCharacterEncoding("UTF-8");
     chain.doFilter(request, response);
   }

   @Override
   public void init(FilterConfig filterConfig) throws ServletException {}

   @Override
   public void destroy() {}
 };
}

Servlet encoding globally using maven + guice

1 Answers1