Record-level access
Record-level access supports both Java programs and Java applets when the programs and applets are running on an AS/400 system that is at Version 4 Release 2 (V4R2) or later.
If you are running to an AS/400 system that is at an earlier level (V3R2,
V3R7,
or V4R1), record-level access supports only Java applications.
Applets do not work.
The record-level access classes provide the ability to do the following:
- Create an AS/400 physical file specifying one of the following:
- The record length
- An existing data description specifications (DDS) source file
- A RecordFormat object
- Retrieve the record format from an AS/400 physical or logical file,
or the record formats from an AS/400 multiple format logical file.
Note: The record format of the file is not retrieved in its entirety. The record formats retrieved are meant to be used when setting the record format for an AS400File object. Only enough information is retrieved to describe the contents of a record of the file. Record format information, such as column headings and aliases, is not retrieved.
- Access the records in an AS/400 file sequentially, by record number, or by key.
- Write records to an AS/400 file.
- Update records in an AS/400 file sequentially, by record number, or by key.
- Delete records in an AS/400 file sequentially, by record number, or by key.
- Lock an AS/400 file for different types of access.
- Use commitment control to allow a Java program to do the following:
- Start commitment control for the connection.
- Specify different commitment control lock levels for different files.
- Commit and rollback transactions.
- Delete AS/400 files.
- Delete a member from an AS/400 file.
Note:
The record-level access classes do not support logical join files or null key fields. |
The following classes perform these functions:
- The AS400File class is the abstract base class for the record-level access classes.
It provides the methods for sequential record access,
creation and deletion of files and members,
and commitment control activities.
- The KeyedFile class represents an AS/400 file whose access is by key.
- The SequentialFile class represents an AS/400 file whose access is by record number.
- The AS400FileRecordDescription class provides the methods for retrieving the record format of an AS/400 file.
The record-level access classes require an AS400
object that represents the AS/400 system that has the database files.
Using the record-level access classes causes the AS400 object to connect to the AS/400.
See managing connections for information about managing connections.
The record-level access classes require the integrated file system path name of the data base file.
See integrated file system path names for more information.
The record-level access classes use the following:
- The RecordFormat class to describe a record of the database file
- The Record class to provide access to the records of the database file
These classes are described in the data conversion section.
Examples
[ Legal | AS/400 Glossary ]
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