Caused by: java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory

Error assembling WAR: webxml attribute is required
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory

Problem Description

In the process of SpringMVC learning, using full annotation development, configuration file upload and download classes, such an error occurs

Cause Analysis and Solutions

1. Caused by: java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory

The problem shown is where the file upload parser is configured in the WebConfig class I configured

//配置文件上传解析器
    @Bean
    public CommonsMultipartResolver multipartResolver(){
    
    
        CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver();
        return commonsMultipartResolver;
    }

First of all, this problem is because in the pom.xml file, it is indeed related to the configuration of commons-fileupload. After adding this, reload it.

<!--添加fileupload依赖-->
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.3</version>
        </dependency>

2. Error assembling WAR: webxml attribute is required

After I solved the first step, this problem came out again. I wondered if it was because I added the pom.

So I am going to repackage, but, no, I don’t have a web.xml file at all. To
package a war project, it must point to a web.xml file. If there is no one, an error will be reported. The path of the web.xml file can be configured as follows:

<plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-war-plugin</artifactId>
   <configuration>
      <webXml>webapps\WEB-INF\web.xml</webXml>
   </configuration>
</plugin>

Since I use annotations for development and use annotation classes instead of configuration classes (web.xml, SpringMVC.xml), I need to use a plugin configuration in pom.xml

<build>
       <plugins>
           <plugin>
               <artifactId>maven-war-plugin</artifactId>
               <version>3.2.2</version>
           </plugin>
       </plugins>
    </build>