Let’s use Path.toRealPath() to resolve a /usr/bin/java symlink, that points to /etc/alternatives/java, which is also a symlink, that points to:

Path path = Paths.get("/usr/bin/java");
System.out.printf("'%s'.toRealPath(): %s%n",
                  path, path.toRealPath());

Results:

'/usr/bin/java'.toRealPath(): /usr/lib/jvm/java-8-oracle/jre/bin/java

The same symbolic link, but without following links:

System.out.printf("'%s'.toRealPath(NOFOLLOW_LINKS): %s%n",
                  path, path.toRealPath(NOFOLLOW_LINKS));

Results:

'/usr/bin/java'.toRealPath(NOFOLLOW_LINKS): /usr/bin/java

Again, but this time with redundant elements in between:

Path path = Paths.get("/usr/./bin/java");
System.out.printf("'%s'.toRealPath(NOFOLLOW_LINKS): %s%n",
                  path, path.toRealPath(NOFOLLOW_LINKS));

Results – redundant dot has been removed:

'/usr/./bin/java'.toRealPath(NOFOLLOW_LINKS): /usr/bin/java

Note that toRealPath() also turns relative paths into absolute.

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