Hitachi

Hitachi Advanced Database Application Development Guide


12.2.1 List of the methods in the Wrapper interface

Organization of this subsection

(1) Main functions of the Wrapper interface

The Wrapper interface provides a standardized approach for calling methods that are not JDBC-compliant.

(2) Methods in the Wrapper interface that are supported by HADB

The following table lists and describes the methods in the Wrapper interface that are supported by HADB.

Table 12‒4: Methods in the Wrapper interface

No.

Method of the Wrapper interface

Function

1

isWrapperFor(Class<?> iface)

Returns a value indicating whether a specified class's object can be returned by the unwrap method.

2

unwrap(Class<T> iface)

Returns a specified class's object.

(3) Classes that can be specified

The following table lists the classes that can be specified in unwrap for an interface that has inherited Wrapper.

Table 12‒5: Classes that can be specified in unwrap

No.

Interface

Class that can be specified in unwrap

1

java.sql.Connection

AdbConnection

2

java.sql.DatabaseMetaData

AdbDatabaseMetaData

3

javax.sql.DataSource

AdbDataSource

4

java.sql.ResultSet

AdbResultSet

5

java.sql.ResultSetMetaData

AdbResultSetMetaData

6

java.sql.Statement

AdbStatement

7

java.sql.PreparedStatement

AdbPreparedStatement

8

java.sql.ParameterMetaData

AdbParameterMetaData

(4) Example coding

The following shows an example of Wrapper interface coding:

Connection con = DriverManager.getConnection(url,info);
Class<?> clazz = Class.forName("com.hitachi.hadb.jdbc.AdbConnection");
if(con.isWrapperFor(clazz)){
  AdbConnection acon = (AdbConnection)con.unwrap(clazz);
  acon.xxxx();
}