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The NsSample sample program
The NsSample demonstration program is a simple JDBC application
that interacts with the Network Server.
The NsSample program performs the following tasks:
- Starts the Network Server.
- Checks that the Network Server is running.
- Loads the Network Client driver. (Note that this step is not
necessary if you are running the client on JDK 1.6 or higher. In that
environment, the network client driver loads automatically.)
- Creates the NsSampledb database if not already created.
- Checks to see if the schema is already created, and if not, creates the
schema which includes the SAMPLETBL table and corresponding indexes.
- Connects to the database.
- Loads the schema by inserting data.
- Starts client threads to perform database related operations.
- Has each of the clients perform DML operations (select, insert, delete,
update) using JDBC calls. For example, one client thread establishes an embedded
connection to perform database operations, while another client thread establishes
a client connection to the Network Server to perform database operations.
- Waits for the client threads to finish the tasks.
- Shuts down the Network Server at the end of the demonstration.
You must install the following files in the %DERBY_HOME%\demo\nserverdemo\ directory before you can run the sample program:
- NsSample.java
This is the entry point into the
sample program. The program starts up two client threads. The first client
establishes an embedded connection to perform database operations, and the
second client establishes a client connection to the Network Server to perform
database operations.
You can change the following constants to modify
the sample program:
- NUM_ROWS
- The number of rows that must be initially loaded into the schema.
- ITERATIONS
- The number of iterations for which each client thread does database related
work.
- NUM_CLIENT_THREADS
- The number of clients that you want to run the program against.
- NETWORKSERVER_PORT
- The port on which the Network Server is running.
- NsSampleClientThread.java
This file contains two
Java classes:
- The NsSampleClientThread class extends Thread and instantiates a NsSampleWork
instance.
- The NsSampleWork class contains everything that is required to perform
DML operations using JDBC calls. The doWork method in the NsSampleWork
class represents all the work done as part of this sample program.
- NetworkServerUtil.java
This file contains helper
methods to start the Network Server and to shutdown the server.
The compiled class files for the NsSample program are:
- NsSample.class
- NsSampleClientThread.class
- NsSampleWork.class
- NetworkServerUtil.class
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