SnapshotService (Imixs-Archive API 2.3.0 API)

java.lang.Object
- org.imixs.archive.core.SnapshotService

```
@DeclareRoles(value="org.imixs.ACCESSLEVEL.MANAGERACCESS")
 @RunAs(value="org.imixs.ACCESSLEVEL.MANAGERACCESS")
public class SnapshotService
extends Object
```
This service component provides a mechanism to transfer the content of a workitem into a snapshot workitem. Attached files will be linked from the snapshot-workitem to the origin-workitem. The snapshot process includes the following stages:
1. create a copy of the origin workitem instance
2. compute a snapshot $uniqueId based on the origin workitem suffixed with a timestamp
3. change the type of the snapshot-workitem with the prefix 'snapshot-'
4. If an old snapshot already exists, Files are compared to the current $ files and, if necessary, stored in the Snapshot applied
5. remove the file content form the origin-workitem
6. store the snapshot uniqeId into the origin-workitem as a reference ($snapshotID)
7. remove deprecated snapshots
A snapshot workitem holds a reference to the origin workitem by its own $uniqueId which is always the $uniqueId from the origin workitem suffixed with a timestamp.
```
 7009e427-7078-4492-af78-0a1145a736df-[SNAPSHOT TIMESTAMP]
 
```
During the snapshot creation the snapshot-uniquId is stored into the origin workitem.
The SnapshotService implements the CDI Observer pattern provided from the DocumentService.
Model entries are not part of the snapshot concept
Note: The SnapshotService replaces the BlobWorkitems mechanism which was earlier part of the DMSPlugin from the imixs-marty project. The SnapshotService provides a migration mechanism for old BlobWorkitems. The old BlobWorkitems will not be deleted. If the DMSPlugin is still active and documents from the type 'workitemlob' will be saved, the SnapshotService throws a SnapshotException.
SyncService
Since version 2.0 the SnapshotService can be connected to the ImixsArchiveService. If the environment variable 'ARCHIVE_SERVICE_ENDPONT' is set, than the snapshot service creates a EventLog entry each time a snapshot was generated. The Archive SyncService scans for the EventLog entries in an asynchronous way and pulls the snaphots directly into the Archive (Cassandra).
Version:

2.0

Author:

rsoika

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`ARCHIVE_SERVICE_AUTHMETHOD`
`static String`	`ARCHIVE_SERVICE_DEADLOCK`
`static String`	`ARCHIVE_SERVICE_ENDPOINT`
`static String`	`ARCHIVE_SERVICE_INTERVAL`
`static String`	`ARCHIVE_SERVICE_PASSWORD`
`static String`	`ARCHIVE_SERVICE_USER`
`static String`	`EVENTLOG_TOPIC_ADD`
`static String`	`EVENTLOG_TOPIC_REMOVE`
`static String`	`ITEM_FILEDATA_FILE_COUNT`
`static String`	`ITEM_FILEDATA_FILE_NAMES`
`static String`	`ITEM_MD5_CHECKSUM`
`static String`	`ITEM_SNAPSHOT_OVERWRITEFILECONTENT`
`static String`	`NOSNAPSHOT`
`static String`	`PROPERTY_SNAPSHOT_HISTORY`
`static String`	`PROPERTY_SNAPSHOT_OVERWRITEFILECONTENT`
`static String`	`PROPERTY_SNAPSHOT_WORKITEMLOB_SUPPORT`
`static String`	`REGEX_URL_PATTERN`
`static String`	`SKIPSNAPSHOT`
`static String`	`SNAPSHOTID`
`static String`	`TYPE_PRAFIX`

Constructor Summary

Constructors
Constructor and Description

SnapshotService()

Constructors
Constructor and Description
`SnapshotService()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`List<org.imixs.workflow.ItemCollection>`	`findAllSnapshots(String uniqueid)` This method returns all existing Snapshot-workitems for a given $UNIQUEID.
`org.imixs.workflow.ItemCollection`	`findSnapshot(org.imixs.workflow.ItemCollection workitem)` This method loads the snapshot for a given origin workItem .
`org.imixs.workflow.FileData`	`getWorkItemFile(String uniqueid, String file)` This method returns the fileData from a snapshot by a given origin workItem uniqueid.
`void`	`onDelete(org.imixs.workflow.engine.DocumentEvent documentEvent)` All existing snapshot-workitems will be deleted when the workitem is removed.
`void`	`onSave(org.imixs.workflow.engine.DocumentEvent documentEvent)` The snapshot-workitem is created immediately after the workitem was processed and before the workitem is saved.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - REGEX_URL_PATTERN
```
public static final String REGEX_URL_PATTERN
```
    See Also:
    
    Constant Field Values
  - SNAPSHOTID
```
public static final String SNAPSHOTID
```
    See Also:
    
    Constant Field Values
  - TYPE_PRAFIX
```
public static final String TYPE_PRAFIX
```
    See Also:
    
    Constant Field Values
  - NOSNAPSHOT
```
public static final String NOSNAPSHOT
```
    See Also:
    
    Constant Field Values
  - SKIPSNAPSHOT
```
public static final String SKIPSNAPSHOT
```
    See Also:
    
    Constant Field Values
  - ITEM_FILEDATA_FILE_NAMES
```
public static final String ITEM_FILEDATA_FILE_NAMES
```
    See Also:
    
    Constant Field Values
  - ITEM_FILEDATA_FILE_COUNT
```
public static final String ITEM_FILEDATA_FILE_COUNT
```
    See Also:
    
    Constant Field Values
  - ITEM_SNAPSHOT_OVERWRITEFILECONTENT
```
public static final String ITEM_SNAPSHOT_OVERWRITEFILECONTENT
```
    See Also:
    
    Constant Field Values
  - PROPERTY_SNAPSHOT_WORKITEMLOB_SUPPORT
```
public static final String PROPERTY_SNAPSHOT_WORKITEMLOB_SUPPORT
```
    See Also:
    
    Constant Field Values
  - PROPERTY_SNAPSHOT_HISTORY
```
public static final String PROPERTY_SNAPSHOT_HISTORY
```
    See Also:
    
    Constant Field Values
  - PROPERTY_SNAPSHOT_OVERWRITEFILECONTENT
```
public static final String PROPERTY_SNAPSHOT_OVERWRITEFILECONTENT
```
    See Also:
    
    Constant Field Values
  - ARCHIVE_SERVICE_ENDPOINT
```
public static final String ARCHIVE_SERVICE_ENDPOINT
```
    See Also:
    
    Constant Field Values
  - ARCHIVE_SERVICE_INTERVAL
```
public static final String ARCHIVE_SERVICE_INTERVAL
```
    See Also:
    
    Constant Field Values
  - ARCHIVE_SERVICE_DEADLOCK
```
public static final String ARCHIVE_SERVICE_DEADLOCK
```
    See Also:
    
    Constant Field Values
  - ARCHIVE_SERVICE_USER
```
public static final String ARCHIVE_SERVICE_USER
```
    See Also:
    
    Constant Field Values
  - ARCHIVE_SERVICE_PASSWORD
```
public static final String ARCHIVE_SERVICE_PASSWORD
```
    See Also:
    
    Constant Field Values
  - ARCHIVE_SERVICE_AUTHMETHOD
```
public static final String ARCHIVE_SERVICE_AUTHMETHOD
```
    See Also:
    
    Constant Field Values
  - EVENTLOG_TOPIC_ADD
```
public static final String EVENTLOG_TOPIC_ADD
```
    See Also:
    
    Constant Field Values
  - EVENTLOG_TOPIC_REMOVE
```
public static final String EVENTLOG_TOPIC_REMOVE
```
    See Also:
    
    Constant Field Values
  - ITEM_MD5_CHECKSUM
```
public static final String ITEM_MD5_CHECKSUM
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - SnapshotService
```
public SnapshotService()
```
- Method Detail
  - onSave
```
public void onSave(@Observes
                   org.imixs.workflow.engine.DocumentEvent documentEvent)
```
    The snapshot-workitem is created immediately after the workitem was processed and before the workitem is saved.
  - onDelete
```
public void onDelete(@Observes
                     org.imixs.workflow.engine.DocumentEvent documentEvent)
```
    All existing snapshot-workitems will be deleted when the workitem is removed.
  - findAllSnapshots
```
public List<org.imixs.workflow.ItemCollection> findAllSnapshots(String uniqueid)
```
    This method returns all existing Snapshot-workitems for a given $UNIQUEID. The method queries the possible snapshot id-range for a given $UniqueId sorted by creation date descending.
    
    Parameters:
    
    uniqueid -
    
    Returns:
  - findSnapshot
```
public org.imixs.workflow.ItemCollection findSnapshot(org.imixs.workflow.ItemCollection workitem)
```
    This method loads the snapshot for a given origin workItem .
    
    Parameters:
    
    workitem -
    
    Returns:
    
    ItemCollection - snapshot object if found
  - getWorkItemFile
```
public org.imixs.workflow.FileData getWorkItemFile(String uniqueid,
                                                   String file)
```
    This method returns the fileData from a snapshot by a given origin workItem uniqueid.
    
    Parameters:
    
    uniqueid -
    
    file - - file name
    
    Returns:
    
    FileData object for the given filename.

Class SnapshotService

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

REGEX_URL_PATTERN

SNAPSHOTID

TYPE_PRAFIX

NOSNAPSHOT

SKIPSNAPSHOT

ITEM_FILEDATA_FILE_NAMES

ITEM_FILEDATA_FILE_COUNT

ITEM_SNAPSHOT_OVERWRITEFILECONTENT

PROPERTY_SNAPSHOT_WORKITEMLOB_SUPPORT

PROPERTY_SNAPSHOT_HISTORY

PROPERTY_SNAPSHOT_OVERWRITEFILECONTENT

ARCHIVE_SERVICE_ENDPOINT

ARCHIVE_SERVICE_INTERVAL

ARCHIVE_SERVICE_DEADLOCK

ARCHIVE_SERVICE_USER

ARCHIVE_SERVICE_PASSWORD

ARCHIVE_SERVICE_AUTHMETHOD

EVENTLOG_TOPIC_ADD

EVENTLOG_TOPIC_REMOVE

ITEM_MD5_CHECKSUM

Constructor Detail

SnapshotService

Method Detail

onSave

onDelete

findAllSnapshots

findSnapshot

getWorkItemFile