Spring Boot Maven - How is adding spring-mock breaking this project? - spring

Question

Disclaimer: I'm not a JVM expert, so I don't have a lot of experience with Maven or Spring. My apologies if there are any obvious mistakes.
I've inherited a Java+Kotlin project with a pom.xml as configured at the end of this question.
The problem I'm having is when I add a reference to spring-mock:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-mock</artifactId>
<version>2.0.8</version>
</dependency>
...I get this error:
***************************
APPLICATION FAILED TO START
***************************
Description:
An attempt was made to call a method that does not exist. The attempt was made from the following location:
org.apache.catalina.authenticator.AuthenticatorBase.startInternal(AuthenticatorBase.java:1321)
The following method did not exist:
javax.servlet.ServletContext.getVirtualServerName()Ljava/lang/String;
The method's class, javax.servlet.ServletContext, is available from the following locations:
jar:file:/home/atrauzzi/.m2/repository/javax/servlet/servlet-api/2.3/servlet-api-2.3.jar!/javax/servlet/ServletContext.class
jar:file:/home/atrauzzi/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/9.0.35/tomcat-embed-core-9.0.35.jar!/javax/servlet/ServletContext.class
It was loaded from the following location:
file:/home/atrauzzi/.m2/repository/javax/servlet/servlet-api/2.3/servlet-api-2.3.jar
Action:
Correct the classpath of your application so that it contains a single, compatible version of javax.servlet.ServletContext
Original pom.xml without spring-mock added
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.myproject</groupId>
<artifactId>pdf-things</artifactId>
<version>0.0.1-development</version>
<name>pdf-things</name>
<description>PDF Things</description>
<properties>
<java.version>1.8</java.version>
<maven.test.skip>true</maven.test.skip>
<kotlin.version>1.3.72</kotlin.version>
<kotlin.compiler.progressive>true</kotlin.compiler.progressive>
</properties>
<repositories>
<repository>
<id>AsposeJavaAPI</id>
<name>Aspose Java API</name>
<url>https://artifact.aspose.com/repo/</url>
</repository>
<repository>
<id>central</id>
<name>Maven Central</name>
<url>https://repo1.maven.org/maven2</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>html2pdf</artifactId>
<version>3.0.3</version>
</dependency>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itext7-core</artifactId>
<version>7.1.13</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.aspose</groupId>
<artifactId>aspose-pdf</artifactId>
<version>19.12</version>
</dependency>
<dependency>
<groupId>com.aspose</groupId>
<artifactId>aspose-words</artifactId>
<version>19.1</version>
<classifier>jdk16</classifier>
</dependency>
<dependency>
<groupId>com.aspose</groupId>
<artifactId>aspose-imaging</artifactId>
<version>17.9</version>
<classifier>jdk16</classifier>
</dependency>
<dependency>
<groupId>com.aspose</groupId>
<artifactId>aspose-cells</artifactId>
<version>19.1</version>
</dependency>
<dependency>
<groupId>com.aspose</groupId>
<artifactId>aspose-cells</artifactId>
<version>19.1</version>
<classifier>javadoc</classifier>
</dependency>
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk16</artifactId>
<version>1.46</version>
</dependency>
<dependency>
<groupId>io.minio</groupId>
<artifactId>minio</artifactId>
<version>7.0.1</version>
</dependency>
<dependency>
<groupId>com.azure</groupId>
<artifactId>azure-storage-blob</artifactId>
<version>12.6.0</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.6</version>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-stdlib-jdk8</artifactId>
<version>${kotlin.version}</version>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-test</artifactId>
<version>${kotlin.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springdoc</groupId>
<artifactId>springdoc-openapi-webmvc-core</artifactId>
<version>1.3.9</version>
</dependency>
<dependency>
<groupId>io.swagger.core.v3</groupId>
<artifactId>swagger-annotations</artifactId>
<version>2.1.2</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-maven-plugin</artifactId>
<version>${kotlin.version}</version>
<executions>
<execution>
<id>compile</id>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
<execution>
<id>test-compile</id>
<phase>test-compile</phase>
<goals>
<goal>test-compile</goal>
</goals>
</execution>
</executions>
<configuration>
<jvmTarget>1.8</jvmTarget>
<compilerPlugins>
<!-- Or "jpa" for JPA support -->
<plugin>no-arg</plugin>
</compilerPlugins>
<pluginOptions>
<option>no-arg:annotation=com.my.Annotation</option>
<!-- Call instance initializers in the synthetic constructor -->
<!-- <option>no-arg:invokeInitializers=true</option> -->
</pluginOptions>
</configuration>
<dependencies>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-maven-noarg</artifactId>
<version>${kotlin.version}</version>
</dependency>
</dependencies>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
<executions>
<execution>
<id>default-compile</id>
<phase>none</phase>
</execution>
<execution>
<id>default-testCompile</id>
<phase>none</phase>
</execution>
<execution>
<id>java-compile</id>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
<execution>
<id>java-test-compile</id>
<phase>test-compile</phase>
<goals>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>

Answer 1

You can use mvn dependency:tree to see all of your project's dependencies. With a dependency on spring-mock added to your project, part of that tree is the following:
[INFO] com.myproject:pdf-things:jar:0.0.1-development
[INFO] +- org.springframework:spring-mock:jar:2.0.8:compile
[INFO] | +- commons-logging:commons-logging:jar:1.1:compile
[INFO] | | +- log4j:log4j:jar:1.2.12:compile
[INFO] | | +- logkit:logkit:jar:1.0.1:compile
[INFO] | | +- avalon-framework:avalon-framework:jar:4.1.3:compile
[INFO] | | \- javax.servlet:servlet-api:jar:2.3:compile
It's showing that org.springframework:spring-mock:jar:2.0.8 depends on commons-logging:commons-logging:jar:1.1 which depends on javax.servlet:servlet-api:jar:2.3. You can avoid the problem by excluding the Servlet API:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-mock</artifactId>
<version>2.0.8</version>
<exclusions>
<exclusion>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
</exclusion>
</exclusions>
</dependency>
However, rather than doing this, I'd recommend taking a step back and questioning why you're adding spring-mock to your project. It was released in 2008 and has been out of support for many years. It was part of Spring Framework 2.0.8 and the version of Spring Boot that you're using, 2.3.0.RELEASE, requires Spring Framework 5.2.x.