|
|||||||||
| Home >> All >> org >> apache >> derby >> iapi >> store >> [ access overview ] | PREV CLASS NEXT CLASS | ||||||||
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||
org.apache.derby.iapi.store.access
Interface FileResource
- public interface FileResource
Management of file resources within a database. Suitable for jar files, images etc.
A file resource is identified by the pair (name,generationId). Name is an arbitrary String supplied by the caller. GenerationId is a non-repeating sequence number constructed by the database. Within a database a (name,generationId) pair uniquely identifies a version of a file resource for all time. Newer generation numbers reflect newer versions of the file.
A database supports the concept of a designated current version of a fileResource. The management of the current version is transactional. The following rules apply
- Adding a FileResource makes the added version the current version
- Removing a FileResource removes the current version of the resource. After this operation the database holds no current version of the FileResoure.
- Replacing a FileResource removes the current version of the resource.
For the benefit of replication, a database optionally retains historic versions of stored files. These old versions are useful when processing old transactions in the stage.
| Method Summary | |
long |
add(java.lang.String name,
java.io.InputStream source)
Add a file resource, copying from the input stream. |
org.apache.derby.io.StorageFile |
getAsFile(java.lang.String name)
Get the File handle to a file resource. |
org.apache.derby.io.StorageFile |
getAsFile(java.lang.String name,
long generationId)
Get the File handle to a file resource. |
java.io.InputStream |
getAsStream(java.lang.String name)
Get the file resource as a stream. |
java.io.InputStream |
getAsStream(java.lang.String name,
long generationId)
Get the file resource as a stream. |
char |
getSeparatorChar()
|
void |
purgeOldGenerations(DatabaseInstant purgeTo)
Purge old generations that were removed or replaced before the database instant provided. |
void |
remove(java.lang.String name,
long currentGenerationId,
boolean purgeOnCommit)
Remove the current generation of a file resource from the database. |
long |
replace(java.lang.String name,
long currentGenerationId,
java.io.InputStream source,
boolean purgeOnCommit)
Replace a file resource with a new version. |
| Method Detail |
add
public long add(java.lang.String name, java.io.InputStream source) throws org.apache.derby.iapi.error.StandardException
- Add a file resource, copying from the input stream.
The InputStream will be closed by this method.
remove
public void remove(java.lang.String name, long currentGenerationId, boolean purgeOnCommit) throws org.apache.derby.iapi.error.StandardException
- Remove the current generation of a file resource from
the database.
replace
public long replace(java.lang.String name, long currentGenerationId, java.io.InputStream source, boolean purgeOnCommit) throws org.apache.derby.iapi.error.StandardException
- Replace a file resource with a new version.
The InputStream will be closed by this method.
getAsFile
public org.apache.derby.io.StorageFile getAsFile(java.lang.String name, long generationId)
- Get the File handle to a file resource. In some situations
higher level code can make optimisations if it can access
a file as a File, rather than an output stream. If this call
returns null then the resouce is not accessable as a file
(e.g. the database is in a zip file).
getAsFile
public org.apache.derby.io.StorageFile getAsFile(java.lang.String name)
- Get the File handle to a file resource. In some situations
higher level code can make optimisations if it can access
a file as a File, rather than an output stream. If this call
returns null then the resouce is not accessable as a file
(e.g. the database is in a zip file).
getAsStream
public java.io.InputStream getAsStream(java.lang.String name, long generationId) throws java.io.IOException
- Get the file resource as a stream.
getAsStream
public java.io.InputStream getAsStream(java.lang.String name) throws java.io.IOException
- Get the file resource as a stream.
purgeOldGenerations
public void purgeOldGenerations(DatabaseInstant purgeTo) throws org.apache.derby.iapi.error.StandardException
- Purge old generations that were removed or replaced
before the database instant provided.
getSeparatorChar
public char getSeparatorChar()
|
|||||||||
| Home >> All >> org >> apache >> derby >> iapi >> store >> [ access overview ] | PREV CLASS NEXT CLASS | ||||||||
|
SUMMARY: JAVADOC | SOURCE | DOWNLOAD | NESTED | FIELD | CONSTR | METHOD |
DETAIL: FIELD | CONSTR | METHOD | ||||||||