public class MqttDefaultFilePersistence extends java.lang.Object implements MqttClientPersistence
MqttClientPersistence
interface that provides
file based persistence.
A directory is specified when the Persistence object is created. When the persistence
is then opened (see open(String, String)
), a sub-directory is made beneath the base
for this client ID and connection key. This allows one persistence base directory
to be shared by multiple clients.
The sub-directory's name is created from a concatenation of the client ID and connection key
with any instance of '/', '\\', ':' or ' ' removed.Constructor and Description |
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MqttDefaultFilePersistence() |
MqttDefaultFilePersistence(java.lang.String directory)
Create an file-based persistent data store within the specified directory.
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Modifier and Type | Method and Description |
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void |
clear()
Clears persistence, so that it no longer contains any persisted data.
|
void |
close()
Close the persistent store that was previously opened.
|
boolean |
containsKey(java.lang.String key)
Returns whether or not data is persisted using the specified key.
|
MqttPersistable |
get(java.lang.String key)
Gets the specified data out of the persistent store.
|
java.util.Enumeration |
keys()
Returns all of the persistent data from the previously specified persistence directory.
|
void |
open(java.lang.String clientId,
java.lang.String theConnection)
Initialise the persistent store.
|
void |
put(java.lang.String key,
MqttPersistable message)
Writes the specified persistent data to the previously specified persistence directory.
|
void |
remove(java.lang.String key)
Deletes the data with the specified key from the previously specified persistence directory.
|
public MqttDefaultFilePersistence()
public MqttDefaultFilePersistence(java.lang.String directory)
directory
- the directory to use.public void open(java.lang.String clientId, java.lang.String theConnection) throws MqttPersistenceException
MqttClientPersistence
open
in interface MqttClientPersistence
clientId
- The client for which the persistent store should be opened.theConnection
- The connection string as specified when the MQTT client instance was created.MqttPersistenceException
- if there was a problem opening the persistent store.public void close() throws MqttPersistenceException
MqttClientPersistence
close
in interface MqttClientPersistence
MqttPersistenceException
public void put(java.lang.String key, MqttPersistable message) throws MqttPersistenceException
put
in interface MqttClientPersistence
message
- key
- the key for the data, which will be used later to retrieve it.MqttPersistenceException
public MqttPersistable get(java.lang.String key) throws MqttPersistenceException
MqttClientPersistence
get
in interface MqttClientPersistence
key
- the key for the data, which was used when originally saving it.MqttPersistenceException
- if there was a problem getting the data
from the persistent store.public void remove(java.lang.String key) throws MqttPersistenceException
remove
in interface MqttClientPersistence
MqttPersistenceException
public java.util.Enumeration keys() throws MqttPersistenceException
keys
in interface MqttClientPersistence
MqttPersistenceException
public boolean containsKey(java.lang.String key) throws MqttPersistenceException
MqttClientPersistence
containsKey
in interface MqttClientPersistence
key
- the key for data, which was used when originally saving it.MqttPersistenceException
public void clear() throws MqttPersistenceException
MqttClientPersistence
clear
in interface MqttClientPersistence
MqttPersistenceException