PAL(Predictive Analysis Library) and Native Application development in SAP HANA

Hi,

I am new to SAP HANA and working on some application development using HANA. I have few question below:

Q1. Can we add my own algorithms to PAL(Predictive Analysis Library)  ? If yes, where I have to make the changes and what all programming  language support it provides?

Q2. According to the SAP HANA introductory guide, we can build "Native Applications" with SAP HANA. Suppose If I have written my middle ware logic in JAVA then where I have to keep this code?

Please help me. Thanks in advance.

Thanks,
Mayank