com.tangosol.util
Class NullFilter

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.NullFilter

All Implemented Interfaces:

ExternalizableLite, PortableObject, Filter, Serializable

public class NullFilter
extends Base
implements Filter, Serializable, ExternalizableLite, PortableObject

Filter which discards null references.

Version:

1.00 08/17/98

Author:

Cameron Purdy

Constructor Summary

NullFilter()
Default constructor (for ExternalizableLite and PortableObject).

Method Summary

boolean	equals(Object o) Compare the NullFilter with another object to determine equality.
boolean	evaluate(Object o) Filter interface: evaluate().
static NullFilter	getInstance() Returns an instance of the null enumerator.
int	hashCode() Determine a hash value for the NullFilter object according to the general Object.hashCode() contract.
void	readExternal(DataInput in) Restore the contents of this object by loading the object's state from the passed DataInput object.
void	readExternal(PofReader in) Restore the contents of a user type instance by reading its state using the specified PofReader object.
String	toString() Return a human-readable description for this Filter.
void	writeExternal(DataOutput out) Save the contents of this object by storing the object's state into the passed DataOutput object.
void	writeExternal(PofWriter out) Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

Constructor Detail

NullFilter

public NullFilter()

Default constructor (for ExternalizableLite and PortableObject).

Method Detail

evaluate

public boolean evaluate(Object o)

Filter interface: evaluate().

Specified by:

evaluate in interface Filter

Returns:

true if the test passes, false otherwise

equals

public boolean equals(Object o)

Compare the NullFilter with another object to determine equality.

Returns:

true iff this NullFilter and the passed object are equivalent NullFilters

hashCode

public int hashCode()

Determine a hash value for the NullFilter object according to the general Object.hashCode() contract.

Returns:

an integer hash value for this NullFilter object

toString

public String toString()

Return a human-readable description for this Filter.

Returns:

a String description of the Filter

readExternal

public void readExternal(DataInput in)
                  throws IOException

Restore the contents of this object by loading the object's state from the passed DataInput object.

Specified by:

readExternal in interface ExternalizableLite

Parameters:

in - the DataInput stream to read data from in order to restore the state of this object

Throws:

IOException - if an I/O exception occurs

NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

writeExternal

public void writeExternal(DataOutput out)
                   throws IOException

Save the contents of this object by storing the object's state into the passed DataOutput object.

Specified by:

writeExternal in interface ExternalizableLite

Parameters:

out - the DataOutput stream to write the state of this object to

Throws:

IOException - if an I/O exception occurs

readExternal

public void readExternal(PofReader in)
                  throws IOException

Restore the contents of a user type instance by reading its state using the specified PofReader object.

Specified by:

readExternal in interface PortableObject

Parameters:

in - the PofReader from which to read the object's state

Throws:

IOException - if an I/O error occurs

writeExternal

public void writeExternal(PofWriter out)
                   throws IOException

Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

Specified by:

writeExternal in interface PortableObject

Parameters:

out - the PofWriter to which to write the object's state

Throws:

IOException - if an I/O error occurs

getInstance

public static final NullFilter getInstance()

Returns an instance of the null enumerator.

Returns:

an Enumeration instance with no values to enumerate.