Providing WS in ABAP and consuming the WS in JAVA and vice-versa

Hi Folks,

Pls help me in creating the below mentioned scenarios.

1) Providing Webservice in ABAP and Consuming in JAVA.

2) Providing Webservice in JAVA and consuming in ABAP.

Also...pls let me know what are the system requirements for the above 2 scenarios...

Cheers...

Ram.