Module org.snmp4j.agent

Package org.snmp4j.agent.mo

Interface MOTable<R extends MOTableRow,C extends MOColumn,M extends MOTableModel<R>>

All Superinterfaces:

ChangeableManagedObject<SubRequest<?>>, GenericManagedObject, ManagedObject<SubRequest<?>>, ManagedObjectValueAccess<SubRequest<?>>

All Known Implementing Classes:

DefaultMOTable, SNMPv2MIB.SysOREntry

public interface MOTable<R extends MOTableRow,C extends MOColumn,M extends MOTableModel<R>>
extends GenericManagedObject, ManagedObjectValueAccess<SubRequest<?>>, ChangeableManagedObject<SubRequest<?>>

The MOTable interface describes SNMP conceptual tables. In general, a conceptual table can be implemented in two different ways:

• For large tables, a virtual table model is best suited where rows are created on behalf of a request only. The instrumentation directly propagates data to the managed objects without holding the data in a table model.
• For small or medium size tables, holding the data in (non virtual) table model provides data caching and decoupling of the instrumentation.

Version:

3.1.0

Author:

Frank Fock

Method Summary

Modifier and Type	Method	Description
void	addMOTableRowListener(MOTableRowListener<R> l)	Adds a MOTableRowListener listener that needs to be informed about row changes (creation, addition, removal).
R	addNewRow(org.snmp4j.smi.OID index, org.snmp4j.smi.Variable[] initialValues)	Creates a new row for this table with the supplied index and initial values and then immediately calls addRow(MOTableRow).
boolean	addRow(R row)	Adds the supplied row to the underlying table model and fires the appropriate MOTableRowEvent.
R	createRow(org.snmp4j.smi.OID index)	Creates a new row for this table with the supplied index and default values.
R	createRow(org.snmp4j.smi.OID index, org.snmp4j.smi.Variable[] initialValues)	Creates a new row for this table with the supplied index and initial values.
org.snmp4j.smi.OID	find(MOScope range)	Finds the object identifier of the first object instance in the specified range.
MOTableCellInfo	getCellInfo(org.snmp4j.smi.OID oid)	Returns a MOTableCellInfo instance for the supplied cell OID.
C	getColumn(int index)	Gets the column definition for the specified column.
int	getColumnCount()	Returns the number of columns in this table.
int	getColumnIndex(int id)	Returns the zero based column index for the specified column sub-identifier.
C[]	getColumns()	Gets the column definitions for this table.
org.snmp4j.smi.Variable[]	getDefaultValues()	Returns an array of variables where each variable corresponds to the column with the same index.
MOTableIndex	getIndexDef()	Gets the index definition of this table.
org.snmp4j.smi.OID	getIndexPart(org.snmp4j.smi.OID instanceIdentifier)	Returns the index part of a column instance identifier of this table.
M	getModel()	Gets the table model of this table.
org.snmp4j.smi.OID	getOID()	Returns the OID of the table entry.
org.snmp4j.smi.Variable	getValue(org.snmp4j.smi.OID cellOID)	Gets the value of the cell instance with the specified instance OID.
org.snmp4j.smi.Variable	getValue(org.snmp4j.smi.OID index, int col)	Gets the value of the cell instance in the specified column and row.
void	removeMOTableRowListener(MOTableRowListener<R> l)	Removes MOTableRowListener instance.
R	removeRow(org.snmp4j.smi.OID index)	Removes the row with the specified index and returns it if the operation was successful.

Methods inherited from interface org.snmp4j.agent.mo.ChangeableManagedObject

addMOChangeListener, removeMOChangeListener

Methods inherited from interface org.snmp4j.agent.ManagedObject

cleanup, commit, get, getScope, next, prepare, undo

Methods inherited from interface org.snmp4j.agent.ManagedObjectValueAccess

setValue

Method Detail

find

org.snmp4j.smi.OID find(MOScope range)

Finds the object identifier of the first object instance in the specified range.

Specified by:

find in interface ManagedObject<R extends MOTableRow>

Parameters:

range - a MOScope specifying the search range.

Returns:

the OID of the lexicographic first instance in the search range or null if no such instance exists.

getColumnIndex

int getColumnIndex(int id)

Returns the zero based column index for the specified column sub-identifier.

Parameters:

id - a column sub-identifier (normally one based) as defined in the MIB specification.

Returns:

a value greater or equal to zero denoting the column index of the column associated with id. The column index points into the column array returned by getColumns(). A value less than zero indicates that such a column does not exists currently but could be inserted at the (-n)-1 position if n is the returned value.

getColumns

C[] getColumns()

Gets the column definitions for this table.

Returns:

an array with the column definitions of this table.

getColumn

C getColumn(int index)

Gets the column definition for the specified column.

Parameters:

index - the (zero-based) column index.

Returns:

a MOColumn instance describing the attributes of requested column.

getCellInfo

MOTableCellInfo getCellInfo(org.snmp4j.smi.OID oid)

Returns a MOTableCellInfo instance for the supplied cell OID. The returned object contains the index, column index, and column ID of the specified cell, if available.

Parameters:

oid - cell instance OID.

Returns:

a MOTableCellInfo instance with the index, column index and column ID of the specified cell if available.

getColumnCount

int getColumnCount()

Returns the number of columns in this table.

Returns:

the column count.

getIndexDef

MOTableIndex getIndexDef()

Gets the index definition of this table.

Returns:

a MOTableIndex instance containing the sub-index definitions for this table.

getIndexPart

org.snmp4j.smi.OID getIndexPart(org.snmp4j.smi.OID instanceIdentifier)

Returns the index part of a column instance identifier of this table.

Parameters:

instanceIdentifier - the OID of a column instance. The returned result is undefined, when this OID is not a column instance OID.

Returns:

an OID representing the index OID of the row identified by the instanceIdentifier column instance OID.

getModel

M getModel()

Gets the table model of this table.

Returns:

a MOTableModel instance.

getOID

org.snmp4j.smi.OID getOID()

Returns the OID of the table entry.

Returns:

a table entry OID (including the .1 suffix).

getDefaultValues

org.snmp4j.smi.Variable[] getDefaultValues()

Returns an array of variables where each variable corresponds to the column with the same index. If a column has a default value, the returned variable is not null and contains that default value.

Returns:

the default variables for a newly created row as an array of Variable instances.

getValue

org.snmp4j.smi.Variable getValue(org.snmp4j.smi.OID cellOID)

Gets the value of the cell instance with the specified instance OID.

Specified by:

getValue in interface ManagedObjectValueAccess<R extends MOTableRow>

Parameters:

cellOID - the instance OID of the requested cell.

Returns:

the value of the cell or null if such a cell does not exist.

getValue

org.snmp4j.smi.Variable getValue(org.snmp4j.smi.OID index,
                                 int col)

Gets the value of the cell instance in the specified column and row.

Parameters:

index - the row index of the cell.

col - the column index of the cell.

Returns:

the value of the cell or null if such a cell does not exist.

addMOTableRowListener

void addMOTableRowListener(MOTableRowListener<R> l)

Adds a MOTableRowListener listener that needs to be informed about row changes (creation, addition, removal).

Parameters:

l - a MOTableRowListener instance.

removeMOTableRowListener

void removeMOTableRowListener(MOTableRowListener<R> l)

Removes MOTableRowListener instance.

Parameters:

l - a MOTableRowListener instance.

createRow

R createRow(org.snmp4j.smi.OID index,
            org.snmp4j.smi.Variable[] initialValues)

Creates a new row for this table with the supplied index and initial values. If one of the MOTableRowListener deny the row creation attempt then null will be returned.

Parameters:

index - the index OID of the new row.

initialValues - the initial values that should be assigned to the new row.

Returns:

the created MOTableRow instance or null if the row cannot be created.

addNewRow

R addNewRow(org.snmp4j.smi.OID index,
            org.snmp4j.smi.Variable[] initialValues)

Creates a new row for this table with the supplied index and initial values and then immediately calls addRow(MOTableRow). If one of the MOTableRowListener deny the row creation attempt then null will be returned and addRow(MOTableRow) will not be called.

This method is the same as calling:

 R newRow = createRow(index, initialValues);
   if (newRow != null) {
     addRow(newRow);
   }
   return newRow;
 

Parameters:

index - the index OID of the new row.

initialValues - the initial values that should be assigned to the new row.

Returns:

the created MOTableRow instance or null if the row cannot be created.

Since:

2.2

createRow

R createRow(org.snmp4j.smi.OID index)

Creates a new row for this table with the supplied index and default values. If one of the MOTableRowListener deny the row creation attempt then null will be returned.

Parameters:

index - the index OID of the new row.

Returns:

the created MOTableRow instance or null if the row cannot be created.

addRow

boolean addRow(R row)

Adds the supplied row to the underlying table model and fires the appropriate MOTableRowEvent. Since this method is typically called during the commit phase of a SET request that creates a table, it should be avoided to return an error here. Instead error checking should be placed in the

Parameters:

row - the MOTableRow to add.

Returns:

true if the row has been added or false if it could not be added.

removeRow

R removeRow(org.snmp4j.smi.OID index)

Removes the row with the specified index and returns it if the operation was successful.

Parameters:

index - the index OID of the row to remove.

Returns:

the removed row or null if the row cannot be found or cannot be removed.