reduce size of jar with shade and proguard

pom-shade-proguard.xml

<?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>x</groupId>
    <artifactId>y</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>y</name>

    <dependencies>
        <dependency>
            <groupId>com.goebl</groupId>
            <artifactId>david-webb</artifactId>
            <version>1.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20140107</version>
        </dependency>
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.10</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>2.3</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <filters>
                        <filter>
                            <artifact>*:*</artifact>
                            <excludes>
                                <exclude>META-INF/maven/</exclude>
                                <exclude>META-INF/*.SF</exclude>
                                <exclude>META-INF/*.DSA</exclude>
                                <exclude>META-INF/*.RSA</exclude>
                            </excludes>
                        </filter>
                    </filters>
                    <minimizeJar>true</minimizeJar>
                    <shadedArtifactAttached>true</shadedArtifactAttached>
                    <transformers>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                            <manifestEntries>
                                <Main-Class>${mainClass}</Main-Class>
                            </manifestEntries>
                        </transformer>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.ApacheLicenseResourceTransformer"></transformer>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.ApacheNoticeResourceTransformer">
                            <addHeader>false</addHeader>
                        </transformer>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.DontIncludeResourceTransformer">
                            <resource>.txt</resource>
                        </transformer>
                    </transformers>
                    <relocations>
                        <relocation>
                            <pattern>com</pattern>
                            <shadedPattern>hidden.com</shadedPattern>
                        </relocation>
                        <relocation>
                            <pattern>org</pattern>
                            <shadedPattern>hidden.org</shadedPattern>
                        </relocation>
                    </relocations>
                </configuration>
            </plugin>
<!--            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.4</version>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>${mainClass}</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>-->
            <plugin>
                <groupId>com.github.wvengen</groupId>
                <artifactId>proguard-maven-plugin</artifactId>
                <version>2.0.9</version>
                <executions>
<!--                    <execution>
                        <id>small</id>
                        <phase>package</phase>
                        <goals>
                            <goal>proguard</goal>
                        </goals>
                        <configuration>
                            <proguardVersion>5.2</proguardVersion>
                            <attach>true</attach>
                            <options>
                                <option>-optimizationpasses 5</option>
                                <option>-overloadaggressively</option>
                                <option>-allowaccessmodification</option>
                                <option>-repackageclasses 'hidden'</option>
                                <option>-keep public class ${mainClass} { public static void main(java.lang.String[]); }</option>
                            </options>
                            <assembly>
                                <inclusions>
                                    <inclusion>
                                        <groupId>com.goebl</groupId>
                                        <artifactId>david-webb</artifactId>
                                    </inclusion>
                                    <inclusion>
                                        <groupId>org.json</groupId>
                                        <artifactId>json</artifactId>
                                    </inclusion>
                                    <inclusion>
                                        <groupId>commons-codec</groupId>
                                        <artifactId>commons-codec</artifactId>
                                        <filter>!**/*.txt</filter>
                                    </inclusion>
                                </inclusions>
                            </assembly>
                            <libs>
                                <lib>${java.home}/lib/rt.jar</lib>
                                <lib>${java.home}/lib/jce.jar</lib>
                            </libs>
                        </configuration>
                    </execution>-->
                    <execution>
                        <id>shaded-small</id>
                        <phase>package</phase>
                        <goals>
                            <goal>proguard</goal>
                        </goals>
                        <configuration>
                            <proguardVersion>5.2</proguardVersion>
                            <attach>true</attach>
                            <options>
                                <option>-optimizationpasses 5</option>
                                <option>-overloadaggressively</option>
                                <option>-allowaccessmodification</option>
                                <option>-repackageclasses 'hidden'</option>
                                <option>-keep public class ${mainClass} { public static void main(java.lang.String[]); }</option>
                            </options>
                            <injar>${project.build.finalName}-shaded.jar</injar>
                            <includeDependency>false</includeDependency>
                            <libs>
                                <lib>${java.home}/lib/rt.jar</lib>
                                <lib>${java.home}/lib/jce.jar</lib>
                            </libs>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>
        <maven.compiler.debug>true</maven.compiler.debug>
        <maven.compiler.debuglevel>lines,vars,source</maven.compiler.debuglevel>
        <maven.compiler.showDeprecation>true</maven.compiler.showDeprecation>
        <maven.compiler.showWarnings>true</maven.compiler.showWarnings>
        <argLine>-Dfile.encoding=${project.build.sourceEncoding}</argLine>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <mainClass>x.Main</mainClass>
    </properties>

</project>