java - oracle.jdbc.pool.OracleDataSource run a command for every new connection

Question

I would like to execute an ALTER SESSION command on every new connection coming from a particular oracle.jdbc.pool.OracleDataSource connection pool. Is there a way to do that?

Answer 1

如果要部署到应用服务器，请检查配置选项，在许多情况下，您可以在那里配置一些“初始 SQL”。

如果您不能这样做，请oracle.jdbc.pool.OracleDataSource在应用程序级别使用自定义 DataSource 进行包装，然后在应用程序的其余部分使用该自定义 DataSource。就像是：

public class InitialSqlDataSource implements DataSource {
    private DataSource delegate;
    private String initialSql;


    public InitialSqlDataSource(DataSource delegate, String initialSql) {
        this.delegate = delegate;
        this.initialSql = initialSql;
    }

    public void setDelegate(DataSource delegate) {
        this.delegate = delegate;
    }

    public void setInitialSql(String initialSql) {
        this.initialSql = initialSql;
    }

    @Override
    public Connection getConnection() {
        Connection connection = delegate.getConnection();
        if (connection != null && isNew(connection)) {
            issueInitialSql(connection);
        }
        return connection;
    }

    protected boolean isNew(Connection connection) {
        // Logic to find out if connection is a new one
        // or a previously pooled connection. In the worst
        // case you can approximate this logic by always returning 
        // true. This will issue the initial SQL on every retrieval 
        // of a connection from this DataSource. This will
        // add some overhead, but will work in many cases.
        return true;
    }

    protected void issueInitialSql(Connection connection) {
        // A typical JDBC statement execution, adapted to
        // your particular needs
        ...
    }

    // Delegate every other method to this.delegate
    ...
}

Answer 2

您可以在每个新连接上执行自定义代码（或者，在最坏的情况下，在连接池的每个“get”上）。另一方面，如果可行，您可以在特定模式上创建 LOGON TRIGGER。