Adding com.sun.tools.jar in classpath of jar

I'm having trouble using tools.jar present in jdk1.8.0_121/lib/tools.jar.

My $JAVA_HOME is set to:

# echo $JAVA_HOME
/usr/local/java/jdk1.8.0_121

The path to tools.jar is :

# ls /usr/local/java/jdk1.8.0_121/lib/tools.jar
/usr/local/java/jdk1.8.0_121/lib/tools.jar

And I use the following java executable to run the code:

/usr/local/java/jdk1.8.0_161/bin/java

But, when I access the VirtualMachine class, it throws

Caused by: java.lang.ClassNotFoundException: com.sun.tools.attach.VirtualMachine
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_161]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_161]
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338) ~[na:1.8.0_161]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_161]
        ... 72 common frames omitted

Can someone explain why Java is not able to find lib/tools.jar in its classpath & What can I do to correct this behaviour?

To run on my local machine, I've added the following dependency in my pom:

<dependency>
    <groupId>com.sun</groupId>
    <artifactId>tools</artifactId>
    <version>1.8</version>
    <scope>system</scope>
    <systemPath>${java.home}/../lib/tools.jar</systemPath>
</dependency>

But, when I deploy it on the server, this jar is not packaged due to system scope & neither does it find the jar on the server's jdk path.

Isn't it supposed to find all the jdk jars automatically?

I've also tried to add env variable $JAVA_HOME in the class-path entry of jar's MANIFEST file as follows:

Manifest-Version: 1.0
Archiver-Version: Plexus Archiver
Built-By: pankajsinghal
Class-Path: $JAVA_HOME/lib/
Created-By: Apache Maven 3.5.4
Build-Jdk: 1.8.0_181

But, this is also not working. Also, I don't want to add this lib's jar in my code explicitly as it's a JDK lib and I guess the proper way to access this would be from the system's JDK path itself. So, looking for a solution in this direction itself.

Any help is really appreciated.

You have to add that jar in project properties. In eclipse, To Add this Jar to your build path Right click the Project > Build Path > Configure build path> Select Libraries tab > Click Add External Libraries > Select the Jar file.