Sun Microsystems poured millions of dollars into marketing Java. During the dotcom bust billboards, posters, magazine ads, and online ads where common.
This massively accelerated it's adoption curve and built a valuable trademark which would be part of the reason Oracle paid $7 billion to buy it.
This is all true, and it should be noted that at the time of its release in mid 90s, Java was an incredibly fun toy to play with and adoption was enthusiastic, and at least in my case, it was an immediate decision to say goodbye to C++ ("forever" /g) and adopt Java, which also turned out to be a good bet in terms of jobs.
Let's also note that to this day I (or any Java professional) can go and earn a living writing Java and not feel like I'm writing COBOL for a mainframe modulo the Spring framework (which I have avoided, to date.)
SMI did not merely pour money in marketing Java. A lot of loving care by very competent software engineers, some of the best, went into creating Java and its virtual machine. The sweet spot of this language is phenomenally large, imo as an s/e, and accessible to an equally large subset of the programming community (even if they hate it, they can do it), from IT low end to investment banks and up to academic people doing super cool stuff like adding fibers to Java (Kilim). Same story holds for performance. Only on the GUI front did Java drop the ball.
Java is, entirely on its technical merits and utility record to date, one of the most practically effective languages created. Thank you Sun Microsystems.
Also thank you Oracle for buying Sun, when no one else cared about it, for improving Java beyond version 6, bringing MaximeVM out of Sun Labs research into GraalVM research labs, integrating JRockit JIT caching and VM monitoring into OpenJDK, and caring about AOT compilation when Sun left it for commercial 3rd party vendors.
This massively accelerated it's adoption curve and built a valuable trademark which would be part of the reason Oracle paid $7 billion to buy it.