@Entity
public class Department {

    @EmbeddedId
    private DepartmentId departmentId

    private String department;
    private String sub_Department;
    private String division;
}

@Embeddable
public class DepartmentId {
    @Column(name = "")
    private String cost_Center_Code;

    @Column(name = "")
    private String dep_Code;

    //getter, setter methods
}


How to Implement composite primary key with Hibernate Annonations
I am an Indian citizen who left US after completing my masters in Aug 2010. Since then I have never re-entered the US and I stayed only in India. I was in the US only on a student visa and did not have a green card or anything alike.

However, I have been working as an independent contractor for a US software company since Jun 2010. I generate invoices for them and they make payments in my Bank of America account. From there I transfer it back to India.

I had filed an income tax return and paid required taxes in US for the year 2010 when I did stay in US till Aug. For years 2011 and 2012, I was under the impression that I am required neither to pay taxes nor to file a return in US. But I got a notice from IRS saying that I haven't filed any return for year 2011. 

Am I still supposed to file return and pay taxes in US (whatever remains after foreign tax credit for what I pay in India) as my income originates in US?

I have been paying taxes and filing returns regularly in India.
