package common;

import javax.servlet.*;

import java.io.IOException;

public class EncodingFilter implements Filter {

    @Override

    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        servletRequest.setCharacterEncoding("utf-8");

        servletResponse.setCharacterEncoding("utf-8");

        filterChain.doFilter(servletRequest, servletResponse);

    }

    @Override

    public void destroy() {

    }

}

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"

         version="3.1">

    <filter>

        <filter-name>encodingFilter</filter-name>

        <filter-class>common.EncodingFilter</filter-class>

    </filter>

    <filter-mapping>

        <filter-name>encodingFilter</filter-name>

        <url-pattern>/*</url-pattern>

    </filter-mapping>

</web-app>