oracle.jdbc.pool.OracleDataSource爲每個新連接運行一個命令

Question

我想對來自特定oracle.jdbc.pool.OracleDataSource連接池的每個新連接執行ALTER SESSION命令。有沒有辦法做到這一點？

Answer 1

您可以在每個新連接上執行自定義代碼（或者，在最壞的情況下，每個連接池中的「get」）。另一方面，如果可行，您可以在特定模式上創建登錄觸發器。

Answer 2

如果您正在部署到應用程序服務器，請檢查配置選項，在很多情況下，您可以在其中配置一些「初始SQL」。

如果您不能這樣做，請在應用程序級別將oracle.jdbc.pool.OracleDataSource換成自定義數據源，然後在應用程序的其餘部分使用該自定義數據源。像這樣的：

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 
    ... 
}