When SpringBoot integrates web, the error Caused by: java.lang.ClassNotFoundException: javax.servlet.Filter

The following error occurred when using SpringBoot in Idea to integrate web startup:

java.lang.NoClassDefFoundError: javax/servlet/Filter
	at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_101]
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[na:1.8.0_101]
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[na:1.8.0_101]
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) ~[na:1.8.0_101]
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[na:1.8.0_101]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[na:1.8.0_101]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[na:1.8.0_101]
	at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_101]
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[na:1.8.0_101]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_101]
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_101]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_101]
	at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_101]
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[na:1.8.0_101]
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[na:1.8.0_101]
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) ~[na:1.8.0_101]
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[na:1.8.0_101]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[na:1.8.0_101]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[na:1.8.0_101]
	at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_101]
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[na:1.8.0_101]

Solution: remove scope dependency deployment

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <!--<scope>provided</scope>-->
 </dependency>

For details about the role of dependency -->scope-->provided in Maven, see: http://blog.csdn.net/qq_36135928/article/details/79126590 I am here