Is any way to explore the GO packages?
In java, I have using "javap java.lang.String" command for viewing the method inside of the class. Something like this, Is any command is their in GO language ?
I have search the same in google. I didn't get expected result.
Go code is distributed with source and documentation tooling so you just need to search for sources in $GOROOT/src directory or use godoc tool or simply go to http://golang.org/pkg/ for standard library or https://godoc.org/ for many other libraries.
On command line run godoc <pkg name>, example godoc encoding/json.
By the way, you can also get Java library sources so using javap for this is definitely not the shortest path. It also have documentation available online https://docs.oracle.com/javase/8/docs/api/