Baza danych
SQL
Sponge zapewnia wygodną abstrakcję dla ustanowienia połączeń bazy danych które radzą sobie ze złożonościami ustanowienia wydajnego połączenia z JDBC URL.
While the SQL service supports any JDBC connector, the Forge implementation of Sponge only ships with the most common:
MySQL
Sqlite
H2
Ostrzeżenie
Because Sqlite has many limitations, its usage is strongly discouraged except in cases where legacy compatibility is required. H2 is our recommended file-backed database implementation.
Sposób użycia
A data source can be accessed through the plugin’s service manager:
import org.spongepowered.api.Sponge;
import org.spongepowered.api.service.sql.SqlService;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
private SqlService sql;
public DataSource getDataSource(String jdbcUrl) throws SQLException {
if (sql == null) {
sql = Sponge.getServiceManager().provide(SqlService.class).get();
}
return sql.getDataSource(jdbcUrl);
}
// Later on
public void myMethodThatQueries() throws SQLException {
String uri = "jdbc:h2:imalittledatabaseshortandstout.db";
String sql = "SELECT * FROM test_tbl";
try (Connection conn = getDataSource(uri).getConnection();
PreparedStatement stmt = conn.prepareStatement(sql);
ResultSet results = stmt.executeQuery()) {
while (results.next()) {
// ...
}
}
}
JDBC URLs should be obtained from SqlService#getConnectionUrlFromAlias(String), with an alias that
matches one of the JDBC URL aliases listed in Sponge’s global configuration (config/sponge/global.conf
)
under the sponge.sql.aliases
key.
The SQL service provides a pooled connection, so getting a connection from the returned DataSource
is not expensive. Therefore, we recommended not keeping connections around, and closing them soon after use as shown
above. Any PreparedStatement
and ResultSet
created should also be closed after use, with object.close()
or, preferably, through a try-with-resources block.
NoSQL
Sponge does not currently provide any special abstraction over NoSQL databases (MongoDB etc.). Plugins that wish to use NoSQL databases must provide their own connectors.