JDeveloper, Java & XML :: Insert All 20,000 Ename In Table?

inserting data in the table.

We are getting more than 20,000 rows (example: ename) from java and they want to insert all the 20,000 enames together in a table having single column ename. For ex:

create table emp(ename varchar2(10));

Currently they are doing
insert into emp values('raj');
insert into emp values('raja');
.
.
.
so on for 20,000.

They are saying that it hits the performance as we are doing insert for 20,000.

Do we have any way where we can insert all the 20,000 ename in one go.