zmq.io

Class Metadata

java.lang.Object

zmq.io.Metadata

public class Metadata
extends java.lang.Object

The metadata holder class.

The class is thread safe, as it uses a ConcurrentHashMap for the backend

Null value are transformed to empty string.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Metadata.ParseListener Call backs during parsing process

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Map<java.lang.String,java.lang.String>	dictionary
static java.lang.String	IDENTITY
static java.lang.String	PEER_ADDRESS
static java.lang.String	SOCKET_TYPE
static java.lang.String	USER_ID

Constructor Summary

Constructors

Constructor and Description
Metadata()
Metadata(java.util.Map<java.lang.String,java.lang.String> dictionary)
Metadata(java.util.Properties dictionary)

Method Summary

Modifier and Type	Method and Description
byte[]	bytes() Return the content of the metadata as a new byte array, using the specifications of the ZMTP protocol
private byte[]	bytes(java.nio.ByteBuffer buf, int position, int length)
private int	bytesSize() Return an approximate size of the serialization of the metadata, it will probably be higher if there is a lot of non ASCII value in it.
void	clear() Removes all the properties.
boolean	containsKey(java.lang.String property) Returns true if this metada contains the property requested
java.util.Set<java.util.Map.Entry<java.lang.String,java.lang.String>>	entrySet() Returns a Set view of the properties contained in this metadata.
boolean	equals(java.lang.Object other)
java.lang.String	get(java.lang.String property) Returns the value for this property, or null if it does not exist.
int	hashCode()
boolean	isEmpty() Returns true if this map contains no key-value mappings.
java.util.Set<java.lang.String>	keySet() Returns a Set view of the keys contained in this metadata.
void	put(java.lang.String property, java.lang.String value) Define the value for this property.
int	read(java.nio.ByteBuffer msg, int offset, Metadata.ParseListener listener) Deserialize metadata from a ByteBuffer, using the specifications of the ZMTP protocol
int	read(Msg msg, int offset, Metadata.ParseListener listener) Deserialize metadata from a Msg, using the specifications of the ZMTP protocol
void	remove(java.lang.String key) Removes the property for a name from this metada if it is present.
void	set(Metadata zapProperties)
void	set(java.lang.String property, java.lang.String value) Deprecated. Use put(String, String) instead
int	size() Returns the number of properties.
java.lang.String	toString()
java.util.Collection<java.lang.String>	values() Returns a Collection view of the values contained in this metadata.
void	write(java.io.OutputStream stream) Serialize metadata to an output stream, using the specifications of the ZMTP protocol

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

IDENTITY

public static final java.lang.String IDENTITY

See Also:

Constant Field Values

SOCKET_TYPE

public static final java.lang.String SOCKET_TYPE

See Also:

Constant Field Values

USER_ID

public static final java.lang.String USER_ID

See Also:

Constant Field Values

PEER_ADDRESS

public static final java.lang.String PEER_ADDRESS

See Also:

Constant Field Values

dictionary

private final java.util.Map<java.lang.String,java.lang.String> dictionary

Constructor Detail

Metadata

public Metadata()

Metadata

public Metadata(java.util.Properties dictionary)

Metadata

public Metadata(java.util.Map<java.lang.String,java.lang.String> dictionary)

Method Detail

keySet

public java.util.Set<java.lang.String> keySet()

Returns a Set view of the keys contained in this metadata. The set is backed by the metadata, so changes to the map are reflected in the set, and vice-versa. If the metadata is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the metadata, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Returns:

a set view of the keys contained in this metadata

entrySet

public java.util.Set<java.util.Map.Entry<java.lang.String,java.lang.String>> entrySet()

Returns a Set view of the properties contained in this metadata. The set is backed by the metadata, so changes to the metadata are reflected in the set, and vice-versa. If the metadata is modified while an iteration over the set is in progress (except through the iterator's own remove operation, or through the setValue operation on a metadata property returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the metadata, via the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Returns:

a set view of the properties contained in this metadata

values

public java.util.Collection<java.lang.String> values()

Returns a Collection view of the values contained in this metadata. The collection is backed by the metadata, so changes to the map are reflected in the collection, and vice-versa. If the metadata is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding property from the metadata, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Returns:

a collection view of the values contained in this map

remove

public void remove(java.lang.String key)

Removes the property for a name from this metada if it is present.

If this map permits null values, then a return value of null does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to null.

The map will not contain a mapping for the specified key once the call returns.

Parameters:

key - key whose mapping is to be removed from the map

get

public java.lang.String get(java.lang.String property)

Returns the value for this property, or null if it does not exist.

Parameters:

property - the property name

Returns:

the value of the property, or null if it does not exist.

set

@Deprecated
public void set(java.lang.String property,
                            java.lang.String value)

Deprecated. Use put(String, String) instead

Define the value for this property. If the value is null, an empty string is stored instead.

Parameters:

property - the property name

value - value to be associated with the specified property

put

public void put(java.lang.String property,
                java.lang.String value)

Define the value for this property. If the value is null, an empty string is stored instead.

Parameters:

property - the property name

value - value to be associated with the specified property

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object other)

Overrides:

equals in class java.lang.Object

set

public void set(Metadata zapProperties)

isEmpty

public boolean isEmpty()

Returns true if this map contains no key-value mappings.

Returns:

true if this map contains no key-value mappings

containsKey

public boolean containsKey(java.lang.String property)

Returns true if this metada contains the property requested

Parameters:

property - property the name of the property to be tested.

Returns:

true if this metada contains the property

clear

public void clear()

Removes all the properties. The map will be empty after this call returns.

size

public int size()

Returns the number of properties. If it contains more properties than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Returns:

the number of properties

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

bytes

public byte[] bytes()

Return the content of the metadata as a new byte array, using the specifications of the ZMTP protocol

 property = name value
 name = OCTET 1*255name-char
 name-char = ALPHA | DIGIT | "-" | "_" | "." | "+"
 value = 4OCTET *OCTET       ; Size in network byte order
 

Returns:

a new byte array

Throws:

java.lang.IllegalStateException - if the content can't be serialized

bytesSize

private int bytesSize()

Return an approximate size of the serialization of the metadata, it will probably be higher if there is a lot of non ASCII value in it.

Returns:

the size estimation

write

public void write(java.io.OutputStream stream)
           throws java.io.IOException

Serialize metadata to an output stream, using the specifications of the ZMTP protocol

 property = name value
 name = OCTET 1*255name-char
 name-char = ALPHA | DIGIT | "-" | "_" | "." | "+"
 value = 4OCTET *OCTET       ; Size in network byte order
 

Parameters:

stream -

Throws:

java.io.IOException - if an I/O error occurs.

java.lang.IllegalStateException - if one of the properties name size is bigger than 255

read

public int read(Msg msg,
                int offset,
                Metadata.ParseListener listener)

Deserialize metadata from a Msg, using the specifications of the ZMTP protocol

 property = name value
 name = OCTET 1*255name-char
 name-char = ALPHA | DIGIT | "-" | "_" | "." | "+"
 value = 4OCTET *OCTET       ; Size in network byte order
 

Parameters:

msg -

offset -

listener - an optional Metadata.ParseListener, can be null.

Returns:

0 if successful. Otherwise, it returns zmq.ZError.EPROTO or the error value from the Metadata.ParseListener.

read

public int read(java.nio.ByteBuffer msg,
                int offset,
                Metadata.ParseListener listener)

Deserialize metadata from a ByteBuffer, using the specifications of the ZMTP protocol

 property = name value
 name = OCTET 1*255name-char
 name-char = ALPHA | DIGIT | "-" | "_" | "." | "+"
 value = 4OCTET *OCTET       ; Size in network byte order
 

Parameters:

msg -

offset -

listener - an optional Metadata.ParseListener, can be null.

Returns:

0 if successful. Otherwise, it returns zmq.ZError.EPROTO or the error value from the Metadata.ParseListener.

bytes

private byte[] bytes(java.nio.ByteBuffer buf,
                     int position,
                     int length)