can't read /usr/lib/jvm/jdk1.8.0_60/jre/lib/rj.jar proguard netbeans

i am using Ubuntu x64 15.04 and in netbeans ide i am trying to use proguard so created proguard.pro file:

-libraryjars /usr/lib/jvm/jdk1.8.0_60/jre/lib/rj.jar
-libraryjars libs/json-simple-1.1.1.jar
-libraryjars libs/sqlite-jdbc-3.8.10.1.jar
-injars      dist/MyApp.jar
-outjars     dist/MyApp-v1.jar

-keepclasseswithmembers public class * {
  public static void main(java.lang.String[]);
}

-optimizationpasses 3
-overloadaggressively
-repackageclasses ''
-allowaccessmodification

-printmapping proguard-mapping.txt

and modified the build.xml file:

<project name="MyApp" default="default" basedir=".">
<description>Builds, tests, and runs the project MyApp.</description>
<import file="nbproject/build-impl.xml"/>
<target name="-post-jar">
    <taskdef resource="proguard/ant/task.properties" classpath="libs/proguard/proguard.jar" />
    <proguard configuration="proguard.pro"/>
</target>
</project>

but when i try to compile and build MyApp i'm getting below errors:

ProGuard, version 5.2.1
Reading program jar [/home/muhammad/java/MyApp/dist/MyApp.jar]
Reading library jar [/usr/lib/jvm/jdk1.8.0_60/jre/lib/rj.jar]
/home/muhammad/java/MyApp/build.xml:8: 
Can't read [/usr/lib/jvm/jdk1.8.0_60/jre/lib/rj.jar] (No such file or directory)
BUILD FAILED (total time: 0 seconds)

it would be great if any one could help me out to solve this error, at this point i can only think to change the permission for /usr/lib/jvm/jdk1.8.0_60/jre/lib/rj.jar so that netbeans can access it, but want to know is it good to do this.. or is there a proper way to solve it..thanks in advance.

Perhaps a typo---did you mean rt.jar?