I have a project that includes the commons-vfs2 library from org.apache.commons and I would like to "shade" it with the maven-shade-plugin, and also minimizing it.
The problem is that, after I shade the jar, I run it and it tells me it could not find the class org.apache.commons.vfs2.impl.StandardFileSystemManager.
In fact the created jar does not have that class. How comes the shade plugin removes that class? How can I say to the plugin to retain that class?
This is my pom
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>blah</groupId>
<artifactId>MyApp</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<!-- Maven Source Plugin -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<version>3.0.1</version>
<executions>
<execution>
<id>attach-sources</id>
<goals>
<goal>jar</goal>
</goals>
</execution>
</executions>
</plugin>
<!-- Maven JavaDoc Plugin -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>2.10.4</version>
<executions>
<execution>
<id>attach-javadocs</id>
<goals>
<goal>jar</goal>
</goals>
</execution>
</executions>
</plugin>
<!-- Maven Deploy Plugin -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<!-- Maven Shade Plugin -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.0.0</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
</execution>
</executions>
<configuration>
<minimizeJar>true</minimizeJar>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>blah.MyMainFrame</mainClass>
</transformer>
</transformers>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<!-- Apache -->
<org.apache.commons.lang3.version>3.6</org.apache.commons.lang3.version>
<org.apache.commons.collections4.version>4.1</org.apache.commons.collections4.version>
<org.apache.commons.vfs2.version>2.1</org.apache.commons.vfs2.version>
<org.apache.commons.io.version>2.5</org.apache.commons.io.version>
<!-- Lombok -->
<org.projectlombok.version>1.16.18</org.projectlombok.version>
<!-- Jackson -->
<com.fasterxml.jackson.version>2.8.9</com.fasterxml.jackson.version>
<!-- Logging -->
<org.slf4j.version>1.7.25</org.slf4j.version>
<ch.qos.logback.version>1.2.3</ch.qos.logback.version>
<!-- JUnit -->
<junit.version>4.12</junit.version>
</properties>
<dependencies>
<!-- Apache -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>${org.apache.commons.lang3.version}</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-collections4</artifactId>
<version>${org.apache.commons.collections4.version}</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-vfs2</artifactId>
<version>${org.apache.commons.vfs2.version}</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>${org.apache.commons.io.version}</version>
</dependency>
<!-- Lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${org.projectlombok.version}</version>
</dependency>
<!-- Jackson -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${com.fasterxml.jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${com.fasterxml.jackson.version}</version>
<exclusions>
<exclusion>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Logging -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${org.slf4j.version}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${ch.qos.logback.version}</version>
</dependency>
<!-- JUnit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
I use the VFS2 in this code:
import org.apache.commons.vfs2.FileListener;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemManager;
import org.apache.commons.vfs2.VFS;
import org.apache.commons.vfs2.impl.DefaultFileMonitor;
public class FileListenerManager{
private FileSystemManager fsManager;
private DefaultFileMonitor fm;
public FileListenerManager(FileListener fl) throws FileSystemException{
fsManager = VFS.getManager();
fm = new DefaultFileMonitor(fl);
start();
}
public void addFile(File file) throws FileSystemException{
fm.addFile(fsManager.resolveFile(file, file.getAbsolutePath()));
}
public final void start(){
fm.start();
}
public final void stop(){
fm.stop();
}
}
As you can see there is no (explicit) reference to StandardFileSystemManager.
I would like the plugin to take care of what classes or methods should be removed from the final uber jar.
From the VFS.class file I can see that the method VFS.getManager() I called is
public static synchronized FileSystemManager getManager() throws FileSystemException{
if(instance == null){
instance = createManager("org.apache.commons.vfs2.impl.StandardFileSystemManager");
}
return instance;
}
I wonder why the plugin cannot sense the usage of the StandardFileSystemManager class.
Thank you.
