java - ProGuard doesn't obfuscate JAR with dependencies

Question

I have a project with the pom.xml file given below. When I issue the command mvn clean compile assembly:single install I want Maven to generate a JAR, which contains

• all the dependencies and
• obfuscated version of my code.

It doesn't work - my code is not obfuscated in the "jar-with-dependencies" file.

When I run mvn clean compile install the resulting file contains obfuscated code of my application, but no dependencies.

What can I do in order to have a JAR file with all the dependencies and my obfuscated code?

<?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>com.mycompany</groupId>
    <artifactId>myproduct</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <restlet-version>2.3.5</restlet-version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.spongepowered</groupId>
            <artifactId>spongeapi</artifactId>
            <version>3.0.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>org.easytesting</groupId>
            <artifactId>fest-assert-core</artifactId>
            <version>2.0M8</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>1.10.19</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.restlet.jse</groupId>
            <artifactId>org.restlet</artifactId>
            <version>${restlet-version}</version>
        </dependency>
        <dependency>
            <groupId>org.restlet.jse</groupId>
            <artifactId>org.restlet.ext.jackson</artifactId>
            <version>${restlet-version}</version>
        </dependency>
        <dependency>
            <groupId>com.googlecode.json-simple</groupId>
            <artifactId>json-simple</artifactId>
            <version>1.1.1</version>
        </dependency>
    </dependencies>
    <build>
        <resources>
            <resource>
                <directory>${project.basedir}/src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>templating-maven-plugin</artifactId>
                <version>1.0-alpha-3</version>
                <executions>
                    <execution>
                        <id>filter-src</id>
                        <goals>
                            <goal>filter-sources</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
            </plugin>
            <plugin>
                <groupId>com.github.wvengen</groupId>
                <artifactId>proguard-maven-plugin</artifactId>
                <version>2.0.8</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals><goal>proguard</goal></goals>
                    </execution>
                </executions>
                <configuration>
                    <proguardVersion>5.2</proguardVersion>
                    <options>
                        <option>-allowaccessmodification</option>
                        <option>-dontoptimize</option>
                        <option>-dontshrink</option>
                        <option>-dontnote</option>
                        <option>-keepattributes Signature</option>
                        <option>-keep class com.mycompany.MyPlugin { *; }</option>
                    </options>
                    <libs>
                        <lib>${java.home}/lib/rt.jar</lib>
                    </libs>
                    <dependencies>
                        <dependency>
                            <groupId>net.sf.proguard</groupId>
                            <artifactId>proguard-base</artifactId>
                            <version>5.2</version>
                            <scope>runtime</scope>
                        </dependency>
                    </dependencies>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Update 1 (17.01.2016 19:54 MSK): Changed the ProGuard configuration like shown below, but mvn clean compile assembly:single still produces a JAR with unobfuscated class files.

<plugin>
    <groupId>com.github.wvengen</groupId>
    <artifactId>proguard-maven-plugin</artifactId>
    <version>2.0.8</version>
    <executions>
        <execution>
            <phase>package</phase>
            <goals><goal>proguard</goal></goals>
        </execution>
    </executions>
    <configuration>
        <proguardVersion>5.2</proguardVersion>
        <options>
            <option>-allowaccessmodification</option>
            <option>-dontoptimize</option>
            <option>-dontshrink</option>
            <option>-dontnote</option>
            <option>-keepattributes Signature</option>
            <option>-keep class com.mycompany.MyPlugin { *; }</option>
        </options>
        <injar>${project.build.finalName}-jar-with-dependencies.jar</injar>
        <libs>
            <lib>${java.home}/lib/rt.jar</lib>
        </libs>
        <dependencies>
            <dependency>
                <groupId>net.sf.proguard</groupId>
                <artifactId>proguard-base</artifactId>
                <version>5.2</version>
                <scope>runtime</scope>
            </dependency>
        </dependencies>
    </configuration>
</plugin>

Update 2 (17.01.2016 20:29 MSK): mvn clean compile assembly:single install fails. The last messages can be seen here.

Answer 1

proguard-maven-plugin will obfuscate the primary artifact of your project, not the secondary artifact jar-with-dependencies that the maven-assembly-plugin generated.

You need to configure the plugin to obfuscate the jar-with-dependencies by specifying the injar attribute:

Specifies the input jar name (or wars, ears, zips) of the application to be processed.

<injar>${project.build.finalName}-jar-with-dependencies.jar</injar>

Now, there is also a problem in the order of execution of plugins in your POM: we need to make sure that the maven-assembly-plugin is executed before the proguard-maven-plugin. As such, it is best to define an explicit execution for the maven-assembly-plugin bound to the package phase instead of manually invoking it from the command line with assembly:single. This would be the configuration:

<plugin>
    <artifactId>maven-assembly-plugin</artifactId>
    <executions>
        <execution>
            <id>assembly</id>
            <goals>
                <goal>single</goal>
            </goals>
            <phase>package</phase>
            <configuration>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
            </configuration>
        </execution>
    </executions>
</plugin>

and then, you just need to make sure that the proguard-maven-plugin plugin configuration is after that in your POM.

Having done that, invoking Maven with mvn clean install will result in an obfuscated jar with dependencies.

---

To test with your actual POM, I added two repositories:

• https://repo.spongepowered.org/maven to resolve the spongeapi dependency.
• http://maven.restlet.com to resolve the org.restlet.jse dependencies.

With those 2 dependencies, warnings were generated by ProGuard because the org.restlet.ext.jackson dependency utilizes com.sun.msv.* classes that are not on the buildpath. Since I figure that your code is currently working, it means those classes don't need to be included and that those warnings can be ignored. As such, I added the -dontwarn option so that ProGuard doesn't error when there is a warning.

The final POM for which I was able to successfully obfuscate the jar with dependencies is the following:

<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>com.mycompany</groupId>
    <artifactId>myproduct</artifactId>
    <version>1.0-SNAPSHOT</version>
    <repositories>
       <repository>
           <id>spongepowered</id>
           <url>https://repo.spongepowered.org/maven</url>
       </repository>
       <repository>
           <id>restlet</id>
           <url>http://maven.restlet.com</url>
       </repository>
    </repositories>
    <properties>
        <restlet-version>2.3.5</restlet-version>
    </properties>
    <build>
       <resources>
            <resource>
                <directory>${project.basedir}/src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>templating-maven-plugin</artifactId>
                <version>1.0-alpha-3</version>
                <executions>
                    <execution>
                        <id>filter-src</id>
                        <goals>
                            <goal>filter-sources</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <executions>
                    <execution>
                        <id>assembly</id>
                        <goals>
                            <goal>single</goal>
                        </goals>
                        <phase>package</phase>
                        <configuration>
                            <descriptorRefs>
                                <descriptorRef>jar-with-dependencies</descriptorRef>
                            </descriptorRefs>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>com.github.wvengen</groupId>
                <artifactId>proguard-maven-plugin</artifactId>
                <version>2.0.8</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals><goal>proguard</goal></goals>
                        <configuration>
                            <injar>${project.build.finalName}-jar-with-dependencies.jar</injar> <!-- make sure to obfuscate the jar with dependencies -->
                            <proguardVersion>5.2</proguardVersion>
                            <options>
                                <option>-allowaccessmodification</option>
                                <option>-dontoptimize</option>
                                <option>-dontshrink</option>
                                <option>-dontnote</option>
                                <option>-dontwarn</option> <!-- added option to ignore com.sun missing classes -->
                                <option>-keepattributes Signature</option>
                                <option>-keep class com.mycompany.MyPlugin { *; }</option>
                            </options>
                            <libs>
                                <lib>${java.home}/lib/rt.jar</lib>
                            </libs>
                            <dependencies>
                                <dependency>
                                    <groupId>net.sf.proguard</groupId>
                                    <artifactId>proguard-base</artifactId>
                                    <version>5.2</version>
                                    <scope>runtime</scope>
                                </dependency>
                            </dependencies>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    <dependencies>
       <dependency>
            <groupId>org.spongepowered</groupId>
            <artifactId>spongeapi</artifactId>
            <version>3.0.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>org.easytesting</groupId>
            <artifactId>fest-assert-core</artifactId>
            <version>2.0M8</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>1.10.19</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.restlet.jse</groupId>
            <artifactId>org.restlet</artifactId>
            <version>${restlet-version}</version>
        </dependency>
        <dependency>
            <groupId>org.restlet.jse</groupId>
            <artifactId>org.restlet.ext.jackson</artifactId>
            <version>${restlet-version}</version>
        </dependency>
        <dependency>
            <groupId>com.googlecode.json-simple</groupId>
            <artifactId>json-simple</artifactId>
            <version>1.1.1</version>
        </dependency>
    </dependencies>
</project>