Oracle 11.2 client connecting to Oracle 10.2 databases

Question

I have an application which currently uses 10.2.0.4 Oracle Client to connect to Oracle 10.2 databases using java (jdbc).
Now I have to do setup on another linux server and looking into whether I can use 11.2 Oracle clinet avaiable on tcehnet.oracle.com to connect to
10.2 databases. I will be using jdbc for connectivity.

Answer 1

Maybe showing my ignorance here, but doesn't the application itself have to be written to use the jdbc thin driver?
That would not be typical. A Java application will normally be modular as regards DB connections.
1. The app itself will be written to take an instance of the 'Connection' interface
http://docs.oracle.com/javase/6/docs/api/java/sql/Connection.html
2. The actual 'Connection' instance will be created by a factory method or other application independent code at startup and then passed to the application code.
Just like TNSNAMES.ORA contains the parameters for OCI connections an application will normally use a config file and/or command-line parameters for the JDBC connection parameters.
Naturally, just like everything else, developers can always screw things up by hard coding values. Nothing you can do about that.
See the 'Database URLs and Database Specifiers' section of the JDBC dev guide
http://docs.oracle.com/cd/E11882_01/java.112/e16548/urls.htm#BEIJFHHB
Database URLs are strings. The complete URL syntax is:
jdbc:oracle:driver_type:[username/password]@database_specifier 
Note:
  The brackets indicate that the username/password pair is optional.
  kprb, the internal server-side driver, uses an implicit connection. Database URLs for the server-side driver end after the driver_type.
The first part of the URL specifies which JDBC driver is to be used. The supported driver_type values are thin, oci, and kprb.
The remainder of the URL contains an optional user name and password separated by a slash, an @, and the
database specifier, which uniquely identifies the database to which the application is connected. Some database specifiers are valid only for the JDBC Thin driver, some only for the JDBC OCI driver, and some for both.
Then there are examples of each driver type in 'Table 8-3 Supported Database Specifiers'
Thin: "jdbc:oracle:thin:scott/tiger@//myhost:1521/myservicename"
See that table 8-3 for the different OCI options.