Java how to use cachedrowset in jdbc
The CachedRowSet
class is a RowSet
implementation that provides a way to cache its data in memory. It is a disconnected RowSet
which means it does not maintain an active connection to the database, but instead it stores the data in memory, which makes it more efficient and faster than other RowSet
implementations.
Here is an example code snippet that demonstrates how to use CachedRowSet
in JDBC:
import java.sql.*; import javax.sql.rowset.*; public class CachedRowSetExample { public static void main(String[] args) throws SQLException { String url = "jdbc:mysql://localhost:3306/mydb"; String username = "root"; String password = "mypassword"; try (Connection conn = DriverManager.getConnection(url, username, password)) { Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery("SELECT * FROM mytable"); // Create a new CachedRowSet CachedRowSet cachedRowSet = RowSetProvider.newFactory().createCachedRowSet(); cachedRowSet.populate(rs); // Close the ResultSet and Statement rs.close(); stmt.close(); // Modify the data in the CachedRowSet cachedRowSet.first(); cachedRowSet.updateString("name", "John Smith"); cachedRowSet.updateRow(); // Update the database with the changes in the CachedRowSet cachedRowSet.acceptChanges(conn); } } }
This code retrieves a ResultSet
from a database, populates a new CachedRowSet
with the data, modifies the data in the CachedRowSet
, and then updates the database with the changes made to the CachedRowSet
.
The RowSetProvider
class is a part of the javax.sql.rowset
package, which is used to obtain a factory for RowSet
objects. The createCachedRowSet()
method of this factory is used to create a new CachedRowSet
object.
The populate()
method of the CachedRowSet
class is used to populate the CachedRowSet
with the data from the ResultSet
. This method closes the ResultSet
and the statement used to create it. The CachedRowSet
object can be modified in the same way as a ResultSet
, by calling the appropriate update
and get
methods.
The acceptChanges()
method is called to update the database with the changes made to the CachedRowSet
. This method uses the Connection
object to update the database.
Note that CachedRowSet
can also be used to move the data between tiers or between different layers of an application, making it a powerful tool for managing data in a distributed application.