12.2.1 List of the methods in the Wrapper interface

(1) Main functions of the Wrapper interface

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

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(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.

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(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

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(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();
}

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