Why java is not open source?

Many makers of software have a rather large financial investment into their software, the making of it as well as the invention of intellectual property that defines its core functionality. It's a business, and these businesses hope to gain back money from selling the software.

The open source market allows earning money through secondary channels, such as installation and runtime support, consultation, advertisement, and offers little protection of trade secrets, such as the secret and unique algorithm that lies at the center of the (hypothetical) lottery number prediction software.