Support for Opaque Data Types

Certain JDBC 2.0 interfaces need to be extended to support opaque data types. Some of the methods need an additional length argument to read or write an opaque data type because the JDBC driver cannot look inside an opaque data type to determine the field lengths.

The Informix implementation of UDRs written in Java code provides the following extensions of the JDBC user-defined-type (UDT) support:

• java.sql.SQLUDTInput
• java.sql.SQLUDTOutput

For more information on using an opaque data type in a Java UDR, refer to Using Opaque User-Detfined Types.

java.sql.SQLUDTInput

This class extends java.sql.SQLInput with the following methods:

public String readString(int maxlen) throws SQLException;
public byte[] readBytes(int maxlen) throws SQLException;

java.sql.SQLUDTOutput

This class extends java.sql.SQLOutput with the following methods:

public void writeString(String str, int maxlen) throws SQLException;
public void writeBytes(byte[] b, int maxlen) throws SQLException;