java - Spring data mongoDb Configuration explaination -

i started learning spring , mongodb integration, didn't catch how configuration should properly.

i use official spring docs using java config examples.

here in section 9.3 said can init mongofactorybean , use throw @autowired annotation.

but in section 9.3.4 see initialization of beans using new mongo().

question: can use '@autowired mongo mongo' in case of new mongo()? , should have 2 separate configurations or use configuration in section 9.4.1.

can explain me in easier words how make configuration?