java - DispatcherServlet and web.xml in Spring Boot

Question

I'm currently trying to move my project from Java EE to Spring Boot project. However, i've been stucked and confused on the part with dispatcher servlet and web.xml and it seems like web.xml is no longer being read by the project anymore. The current project is running on tomcat 7.

In my web.xml file, I have lots of servlet, servlet-mapping, filter and filter mapping and I don't really understand how to do the mapping in the dispatcher.

I've attached a sample of my web.xml below and the version is 2.5.

<?xml version="1.0" encoding="UTF-8"?>
<web-app metadata-complete="true" version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <display-name>displayName</display-name>
  <description>description</description>
  <resource-ref>
    ...
  </resource-ref>
  <filter>
    <filter-name>Some Filter Name</filter-name>
    <filter-class>Some Filter Class</filter-class>
    <init-param>
      <param-name>Some Param Name</param-name>
      <param-value>Some Value</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>Some Filter Name</filter-name>
    <url-pattern>Some url-pattern</url-pattern>
  </filter-mapping>
  <context-param>
    <param-name>Some Param Name</param-name>
    <param-value>Some Param Value</param-value>
  </context-param>
  <servlet>
    <servlet-name>Some Servlet Name</servlet-name>
    <servlet-class>Some Servlet Class</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>Some Servlet Name</servlet-name>
    <url-pattern>Some Url Pattern</url-pattern>
  </servlet-mapping>
</web-app>

Answer 1

1. Yes, spring boot no longer relies on xml configuration and it configures an equivalent to the dispatcher servlet automatically. You can follow the following link to see how to register your filters: How to add a filter class in Spring Boot?
2. If you use maven and not gradle, the only XML in your spring boot project should be pom.xml. The way to go with spring boot is moving all your xml configuration, web.xml etc to spring boot's auto configuration + your java configuration.

Spring boot works very good when you do everything in java configuration and follow its principals. From my experience with it, when you start merging XML configuration and the legacy spring it starts breaking the auto configuration process and its much better to try as much as you can to comply with the new spring boot best practices.