NetworkTableInstance

java.lang.Object
- edu.wpi.first.networktables.NetworkTableInstance

```
public final class NetworkTableInstance
extends java.lang.Object
```
NetworkTables Instance. Instances are completely independent from each other. Table operations on one instance will not be visible to other instances unless the instances are connected via the network. The main limitation on instances is that you cannot have two servers on the same network port. The main utility of instances is for unit testing, but they can also enable one program to connect to two different NetworkTables networks. The global "default" instance (as returned by getDefault()) is always available, and is intended for the common case when there is only a single NetworkTables instance being used in the program. Additional instances can be created with the create() function. A reference must be kept to the NetworkTableInstance returned by this function to keep it from being garbage collected.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`kDefaultPort` The default port that network tables operates on.
`static int`	`kNetModeClient`
`static int`	`kNetModeFailure`
`static int`	`kNetModeNone` Client/server mode flag values (as returned by `getNetworkMode()`).
`static int`	`kNetModeServer`
`static int`	`kNetModeStarting`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`addConnectionListener(java.util.function.Consumer<ConnectionNotification> listener, boolean immediateNotify)` Add a connection listener.
`int`	`addEntryListener(NetworkTableEntry entry, java.util.function.Consumer<EntryNotification> listener, int flags)` Add a listener for a particular entry.
`int`	`addEntryListener(java.lang.String prefix, java.util.function.Consumer<EntryNotification> listener, int flags)` Add a listener for all entries starting with a certain prefix.
`int`	`addLogger(java.util.function.Consumer<LogMessage> func, int minLevel, int maxLevel)` Add logger callback function.
`static NetworkTableInstance`	`create()` Create an instance.
`void`	`createRpc(NetworkTableEntry entry, java.util.function.Consumer<RpcAnswer> callback)` Create a callback-based RPC entry point.
`void`	`deleteAllEntries()` Deletes ALL keys in ALL subtables (except persistent values).
`boolean`	`equals(java.lang.Object o)`
`void`	`flush()` Flushes all updated values immediately to the network.
`void`	`free()` Destroys the instance (if created by `create()`).
`ConnectionInfo[]`	`getConnections()` Gets information on the currently established network connections.
`static NetworkTableInstance`	`getDefault()` Get global default instance.
`NetworkTableEntry[]`	`getEntries(java.lang.String prefix, int types)` Get entries starting with the given prefix.
`NetworkTableEntry`	`getEntry(java.lang.String name)` Gets the entry for a key.
`EntryInfo[]`	`getEntryInfo(java.lang.String prefix, int types)` Get information about entries starting with the given prefix.
`int`	`getHandle()` Gets the native handle for the entry.
`int`	`getNetworkMode()` Get the current network mode.
`NetworkTable`	`getTable(java.lang.String key)` Gets the table with the specified key.
`int`	`hashCode()`
`boolean`	`isConnected()` Return whether or not the instance is connected to another node.
`boolean`	`isValid()` Determines if the native handle is valid.
`java.lang.String[]`	`loadEntries(java.lang.String filename, java.lang.String prefix)` Load table values from a file.
`java.lang.String[]`	`loadPersistent(java.lang.String filename)` Loads persistent keys from a file.
`void`	`removeConnectionListener(int listener)` Remove a connection listener.
`void`	`removeEntryListener(int listener)` Remove an entry listener.
`void`	`removeLogger(int logger)` Remove a logger.
`void`	`saveEntries(java.lang.String filename, java.lang.String prefix)` Save table values to a file.
`void`	`savePersistent(java.lang.String filename)` Saves persistent keys to a file.
`void`	`setNetworkIdentity(java.lang.String name)` Set the network identity of this node.
`void`	`setServer(java.lang.String serverName)` Sets server address and port for client (without restarting client).
`void`	`setServer(java.lang.String[] serverNames)` Sets server addresses and port for client (without restarting client).
`void`	`setServer(java.lang.String[] serverNames, int port)` Sets server addresses and port for client (without restarting client).
`void`	`setServer(java.lang.String[] serverNames, int[] ports)` Sets server addresses and ports for client (without restarting client).
`void`	`setServer(java.lang.String serverName, int port)` Sets server address and port for client (without restarting client).
`void`	`setServerTeam(int team)` Sets server addresses and port for client (without restarting client).
`void`	`setServerTeam(int team, int port)` Sets server addresses and port for client (without restarting client).
`void`	`setUpdateRate(double interval)` Set the periodic update rate.
`void`	`startClient()` Starts a client.
`void`	`startClient(java.lang.String serverName)` Starts a client using the specified server and the default port
`void`	`startClient(java.lang.String[] serverNames)` Starts a client using the specified servers and default port.
`void`	`startClient(java.lang.String[] serverNames, int port)` Starts a client using the specified servers and port number.
`void`	`startClient(java.lang.String[] serverNames, int[] ports)` Starts a client using the specified (server, port) combinations.
`void`	`startClient(java.lang.String serverName, int port)` Starts a client using the specified server and port
`void`	`startClientTeam(int team)` Starts a client using commonly known robot addresses for the specified team using the default port number.
`void`	`startClientTeam(int team, int port)` Starts a client using commonly known robot addresses for the specified team.
`void`	`startDSClient()` Starts requesting server address from Driver Station.
`void`	`startDSClient(int port)` Starts requesting server address from Driver Station.
`void`	`startServer()` Starts a server using the networktables.ini as the persistent file, using the default listening address and port.
`void`	`startServer(java.lang.String persistFilename)` Starts a server using the specified persistent filename, using the default listening address and port.
`void`	`startServer(java.lang.String persistFilename, java.lang.String listenAddress)` Starts a server using the specified filename and listening address, using the default port.
`void`	`startServer(java.lang.String persistFilename, java.lang.String listenAddress, int port)` Starts a server using the specified filename, listening address, and port.
`void`	`stopClient()` Stops the client if it is running.
`void`	`stopDSClient()` Stops requesting server address from Driver Station.
`void`	`stopServer()` Stops the server if it is running.
`boolean`	`waitForConnectionListenerQueue(double timeout)` Wait for the connection listener queue to be empty.
`boolean`	`waitForEntryListenerQueue(double timeout)` Wait for the entry listener queue to be empty.
`boolean`	`waitForLoggerQueue(double timeout)` Wait for the incoming log event queue to be empty.
`boolean`	`waitForRpcCallQueue(double timeout)` Wait for the incoming RPC call queue to be empty.

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

- Field Detail
  - kNetModeNone
```
public static final int kNetModeNone
```
    Client/server mode flag values (as returned by getNetworkMode()). This is a bitmask.
    
    See Also:
    
    Constant Field Values
  - kNetModeServer
```
public static final int kNetModeServer
```
    See Also:
    
    Constant Field Values
  - kNetModeClient
```
public static final int kNetModeClient
```
    See Also:
    
    Constant Field Values
  - kNetModeStarting
```
public static final int kNetModeStarting
```
    See Also:
    
    Constant Field Values
  - kNetModeFailure
```
public static final int kNetModeFailure
```
    See Also:
    
    Constant Field Values
  - kDefaultPort
```
public static final int kDefaultPort
```
    The default port that network tables operates on.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - free
```
public void free()
```
    Destroys the instance (if created by create()).
  - isValid
```
public boolean isValid()
```
    Determines if the native handle is valid.
    
    Returns:
    
    True if the native handle is valid, false otherwise.
  - getDefault
```
public static NetworkTableInstance getDefault()
```
    Get global default instance.
    
    Returns:
    
    Global default instance
  - create
```
public static NetworkTableInstance create()
```
    Create an instance. Note: A reference to the returned instance must be retained to ensure the instance is not garbage collected.
    
    Returns:
    
    Newly created instance
  - getHandle
```
public int getHandle()
```
    Gets the native handle for the entry.
    
    Returns:
    
    Native handle
  - getEntry
```
public NetworkTableEntry getEntry(java.lang.String name)
```
    Gets the entry for a key.
    
    Parameters:
    
    name - Key
    
    Returns:
    
    Network table entry.
  - getEntries
```
public NetworkTableEntry[] getEntries(java.lang.String prefix,
                                      int types)
```
    Get entries starting with the given prefix. The results are optionally filtered by string prefix and entry type to only return a subset of all entries.
    
    Parameters:
    
    prefix - entry name required prefix; only entries whose name starts with this string are returned
    
    types - bitmask of types; 0 is treated as a "don't care"
    
    Returns:
    
    Array of entries.
  - getEntryInfo
```
public EntryInfo[] getEntryInfo(java.lang.String prefix,
                                int types)
```
    Get information about entries starting with the given prefix. The results are optionally filtered by string prefix and entry type to only return a subset of all entries.
    
    Parameters:
    
    prefix - entry name required prefix; only entries whose name starts with this string are returned
    
    types - bitmask of types; 0 is treated as a "don't care"
    
    Returns:
    
    Array of entry information.
  - getTable
```
public NetworkTable getTable(java.lang.String key)
```
    Gets the table with the specified key.
    
    Parameters:
    
    key - the key name
    
    Returns:
    
    The network table
  - deleteAllEntries
```
public void deleteAllEntries()
```
    Deletes ALL keys in ALL subtables (except persistent values). Use with caution!
  - addEntryListener
```
public int addEntryListener(java.lang.String prefix,
                            java.util.function.Consumer<EntryNotification> listener,
                            int flags)
```
    Add a listener for all entries starting with a certain prefix.
    
    Parameters:
    
    prefix - UTF-8 string prefix
    
    listener - listener to add
    
    flags - EntryListenerFlags bitmask
    
    Returns:
    
    Listener handle
  - addEntryListener
```
public int addEntryListener(NetworkTableEntry entry,
                            java.util.function.Consumer<EntryNotification> listener,
                            int flags)
```
    Add a listener for a particular entry.
    
    Parameters:
    
    entry - the entry
    
    listener - listener to add
    
    flags - EntryListenerFlags bitmask
    
    Returns:
    
    Listener handle
  - removeEntryListener
```
public void removeEntryListener(int listener)
```
    Remove an entry listener.
    
    Parameters:
    
    listener - Listener handle to remove
  - waitForEntryListenerQueue
```
public boolean waitForEntryListenerQueue(double timeout)
```
    Wait for the entry listener queue to be empty. This is primarily useful for deterministic testing. This blocks until either the entry listener queue is empty (e.g. there are no more events that need to be passed along to callbacks or poll queues) or the timeout expires.
    
    Parameters:
    
    timeout - timeout, in seconds. Set to 0 for non-blocking behavior, or a negative value to block indefinitely
    
    Returns:
    
    False if timed out, otherwise true.
  - addConnectionListener
```
public int addConnectionListener(java.util.function.Consumer<ConnectionNotification> listener,
                                 boolean immediateNotify)
```
    Add a connection listener.
    
    Parameters:
    
    listener - Listener to add
    
    immediateNotify - Notify listener of all existing connections
    
    Returns:
    
    Listener handle
  - removeConnectionListener
```
public void removeConnectionListener(int listener)
```
    Remove a connection listener.
    
    Parameters:
    
    listener - Listener handle to remove
  - waitForConnectionListenerQueue
```
public boolean waitForConnectionListenerQueue(double timeout)
```
    Wait for the connection listener queue to be empty. This is primarily useful for deterministic testing. This blocks until either the connection listener queue is empty (e.g. there are no more events that need to be passed along to callbacks or poll queues) or the timeout expires.
    
    Parameters:
    
    timeout - timeout, in seconds. Set to 0 for non-blocking behavior, or a negative value to block indefinitely
    
    Returns:
    
    False if timed out, otherwise true.
  - createRpc
```
public void createRpc(NetworkTableEntry entry,
                      java.util.function.Consumer<RpcAnswer> callback)
```
    Create a callback-based RPC entry point. Only valid to use on the server. The callback function will be called when the RPC is called. This function creates RPC version 0 definitions (raw data in and out).
    
    Parameters:
    
    entry - the entry
    
    callback - callback function
  - waitForRpcCallQueue
```
public boolean waitForRpcCallQueue(double timeout)
```
    Wait for the incoming RPC call queue to be empty. This is primarily useful for deterministic testing. This blocks until either the RPC call queue is empty (e.g. there are no more events that need to be passed along to callbacks or poll queues) or the timeout expires.
    
    Parameters:
    
    timeout - timeout, in seconds. Set to 0 for non-blocking behavior, or a negative value to block indefinitely
    
    Returns:
    
    False if timed out, otherwise true.
  - setNetworkIdentity
```
public void setNetworkIdentity(java.lang.String name)
```
    Set the network identity of this node. This is the name used during the initial connection handshake, and is visible through ConnectionInfo on the remote node.
    
    Parameters:
    
    name - identity to advertise
  - getNetworkMode
```
public int getNetworkMode()
```
    Get the current network mode.
    
    Returns:
    
    Bitmask of NetworkMode.
  - startServer
```
public void startServer()
```
    Starts a server using the networktables.ini as the persistent file, using the default listening address and port.
  - startServer
```
public void startServer(java.lang.String persistFilename)
```
    Starts a server using the specified persistent filename, using the default listening address and port.
    
    Parameters:
    
    persistFilename - the name of the persist file to use
  - startServer
```
public void startServer(java.lang.String persistFilename,
                        java.lang.String listenAddress)
```
    Starts a server using the specified filename and listening address, using the default port.
    
    Parameters:
    
    persistFilename - the name of the persist file to use
    
    listenAddress - the address to listen on, or empty to listen on any address
  - startServer
```
public void startServer(java.lang.String persistFilename,
                        java.lang.String listenAddress,
                        int port)
```
    Starts a server using the specified filename, listening address, and port.
    
    Parameters:
    
    persistFilename - the name of the persist file to use
    
    listenAddress - the address to listen on, or empty to listen on any address
    
    port - port to communicate over
  - stopServer
```
public void stopServer()
```
    Stops the server if it is running.
  - startClient
```
public void startClient()
```
    Starts a client. Use SetServer to set the server name and port.
  - startClient
```
public void startClient(java.lang.String serverName)
```
    Starts a client using the specified server and the default port
    
    Parameters:
    
    serverName - server name
  - startClient
```
public void startClient(java.lang.String serverName,
                        int port)
```
    Starts a client using the specified server and port
    
    Parameters:
    
    serverName - server name
    
    port - port to communicate over
  - startClient
```
public void startClient(java.lang.String[] serverNames)
```
    Starts a client using the specified servers and default port. The client will attempt to connect to each server in round robin fashion.
    
    Parameters:
    
    serverNames - array of server names
  - startClient
```
public void startClient(java.lang.String[] serverNames,
                        int port)
```
    Starts a client using the specified servers and port number. The client will attempt to connect to each server in round robin fashion.
    
    Parameters:
    
    serverNames - array of server names
    
    port - port to communicate over
  - startClient
```
public void startClient(java.lang.String[] serverNames,
                        int[] ports)
```
    Starts a client using the specified (server, port) combinations. The client will attempt to connect to each server in round robin fashion.
    
    Parameters:
    
    serverNames - array of server names
    
    ports - array of port numbers
  - startClientTeam
```
public void startClientTeam(int team)
```
    Starts a client using commonly known robot addresses for the specified team using the default port number.
    
    Parameters:
    
    team - team number
  - startClientTeam
```
public void startClientTeam(int team,
                            int port)
```
    Starts a client using commonly known robot addresses for the specified team.
    
    Parameters:
    
    team - team number
    
    port - port to communicate over
  - stopClient
```
public void stopClient()
```
    Stops the client if it is running.
  - setServer
```
public void setServer(java.lang.String serverName)
```
    Sets server address and port for client (without restarting client). Changes the port to the default port.
    
    Parameters:
    
    serverName - server name
  - setServer
```
public void setServer(java.lang.String serverName,
                      int port)
```
    Sets server address and port for client (without restarting client).
    
    Parameters:
    
    serverName - server name
    
    port - port to communicate over
  - setServer
```
public void setServer(java.lang.String[] serverNames)
```
    Sets server addresses and port for client (without restarting client). Changes the port to the default port. The client will attempt to connect to each server in round robin fashion.
    
    Parameters:
    
    serverNames - array of server names
  - setServer
```
public void setServer(java.lang.String[] serverNames,
                      int port)
```
    Sets server addresses and port for client (without restarting client). The client will attempt to connect to each server in round robin fashion.
    
    Parameters:
    
    serverNames - array of server names
    
    port - port to communicate over
  - setServer
```
public void setServer(java.lang.String[] serverNames,
                      int[] ports)
```
    Sets server addresses and ports for client (without restarting client). The client will attempt to connect to each server in round robin fashion.
    
    Parameters:
    
    serverNames - array of server names
    
    ports - array of port numbers
  - setServerTeam
```
public void setServerTeam(int team)
```
    Sets server addresses and port for client (without restarting client). Changes the port to the default port. The client will attempt to connect to each server in round robin fashion.
    
    Parameters:
    
    team - team number
  - setServerTeam
```
public void setServerTeam(int team,
                          int port)
```
    Sets server addresses and port for client (without restarting client). Connects using commonly known robot addresses for the specified team.
    
    Parameters:
    
    team - team number
    
    port - port to communicate over
  - startDSClient
```
public void startDSClient()
```
    Starts requesting server address from Driver Station. This connects to the Driver Station running on localhost to obtain the server IP address, and connects with the default port.
  - startDSClient
```
public void startDSClient(int port)
```
    Starts requesting server address from Driver Station. This connects to the Driver Station running on localhost to obtain the server IP address.
    
    Parameters:
    
    port - server port to use in combination with IP from DS
  - stopDSClient
```
public void stopDSClient()
```
    Stops requesting server address from Driver Station.
  - setUpdateRate
```
public void setUpdateRate(double interval)
```
    Set the periodic update rate. Sets how frequently updates are sent to other nodes over the network.
    
    Parameters:
    
    interval - update interval in seconds (range 0.01 to 1.0)
  - flush
```
public void flush()
```
    Flushes all updated values immediately to the network. Note: This is rate-limited to protect the network from flooding. This is primarily useful for synchronizing network updates with user code.
  - getConnections
```
public ConnectionInfo[] getConnections()
```
    Gets information on the currently established network connections. If operating as a client, this will return either zero or one values.
    
    Returns:
    
    array of connection information
  - isConnected
```
public boolean isConnected()
```
    Return whether or not the instance is connected to another node.
    
    Returns:
    
    True if connected.
  - savePersistent
```
public void savePersistent(java.lang.String filename)
                    throws PersistentException
```
    Saves persistent keys to a file. The server does this automatically.
    
    Parameters:
    
    filename - file name
    
    Throws:
    
    PersistentException - if error saving file
  - loadPersistent
```
public java.lang.String[] loadPersistent(java.lang.String filename)
                                  throws PersistentException
```
    Loads persistent keys from a file. The server does this automatically.
    
    Parameters:
    
    filename - file name
    
    Returns:
    
    List of warnings (errors result in an exception instead)
    
    Throws:
    
    PersistentException - if error reading file
  - saveEntries
```
public void saveEntries(java.lang.String filename,
                        java.lang.String prefix)
                 throws PersistentException
```
    Save table values to a file. The file format used is identical to that used for SavePersistent.
    
    Parameters:
    
    filename - filename
    
    prefix - save only keys starting with this prefix
    
    Throws:
    
    PersistentException - if error saving file
  - loadEntries
```
public java.lang.String[] loadEntries(java.lang.String filename,
                                      java.lang.String prefix)
                               throws PersistentException
```
    Load table values from a file. The file format used is identical to that used for SavePersistent / LoadPersistent.
    
    Parameters:
    
    filename - filename
    
    prefix - load only keys starting with this prefix
    
    Returns:
    
    List of warnings (errors result in an exception instead)
    
    Throws:
    
    PersistentException - if error saving file
  - addLogger
```
public int addLogger(java.util.function.Consumer<LogMessage> func,
                     int minLevel,
                     int maxLevel)
```
    Add logger callback function. By default, log messages are sent to stderr; this function sends log messages with the specified levels to the provided callback function instead. The callback function will only be called for log messages with level greater than or equal to minLevel and less than or equal to maxLevel; messages outside this range will be silently ignored.
    
    Parameters:
    
    func - log callback function
    
    minLevel - minimum log level
    
    maxLevel - maximum log level
    
    Returns:
    
    Logger handle
  - removeLogger
```
public void removeLogger(int logger)
```
    Remove a logger.
    
    Parameters:
    
    logger - Logger handle to remove
  - waitForLoggerQueue
```
public boolean waitForLoggerQueue(double timeout)
```
    Wait for the incoming log event queue to be empty. This is primarily useful for deterministic testing. This blocks until either the log event queue is empty (e.g. there are no more events that need to be passed along to callbacks or poll queues) or the timeout expires.
    
    Parameters:
    
    timeout - timeout, in seconds. Set to 0 for non-blocking behavior, or a negative value to block indefinitely
    
    Returns:
    
    False if timed out, otherwise true.
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object

Class NetworkTableInstance

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

kNetModeNone

kNetModeServer

kNetModeClient

kNetModeStarting

kNetModeFailure

kDefaultPort

Method Detail

free

isValid

getDefault

create

getHandle

getEntry

getEntries

getEntryInfo

getTable

deleteAllEntries

addEntryListener

addEntryListener

removeEntryListener

waitForEntryListenerQueue

addConnectionListener

removeConnectionListener

waitForConnectionListenerQueue

createRpc

waitForRpcCallQueue

setNetworkIdentity

getNetworkMode

startServer

startServer

startServer

startServer

stopServer

startClient

startClient

startClient

startClient

startClient

startClient

startClientTeam

startClientTeam

stopClient

setServer

setServer

setServer

setServer

setServer

setServerTeam

setServerTeam

startDSClient

startDSClient

stopDSClient

setUpdateRate

flush

getConnections

isConnected

savePersistent

loadPersistent

saveEntries

loadEntries

addLogger

removeLogger

waitForLoggerQueue

equals

hashCode