I am working in java. I am totally new to Salesforce.
I have requirement of exporting data (scheduling a job) from Salesforce and putting it into one database table.
I tried reading http://www.salesforce.com/us/developer/docs/api_asynch/index.htm. But couldn't understand it, may be because of my lack of knowledge in this area.
Can anyone please help me in this. Can any one please provide me simple tutorial or sample example for it.
the link you provided is for the Bulk API documentation. Therefore you will see that in the first paragraph of the introduction "The Bulk API provides programmatic access to allow you to quickly load your organization's data into Salesforce. " This allows you to IMPORT not export. The simplest solution will be for you to use an additional tool called Data Loader that will allow you to export the org data in CSV format and then import this into your database.
You will need to decide is this a once off or regular export or will you be synching ultimately? Additonally here is a good resource for you: Additonal Import/Export Resources for Salesforce