org.apache.hadoop.io
Class MapWritable

java.lang.Object
  extended by org.apache.hadoop.io.AbstractMapWritable
      extended by org.apache.hadoop.io.MapWritable
All Implemented Interfaces:
Map<Writable,Writable>, Configurable, Writable

@InterfaceAudience.Public
@InterfaceStability.Stable
public class MapWritable
extends AbstractMapWritable
implements Map<Writable,Writable>

A Writable Map.


Constructor Summary
MapWritable()
          Default constructor.
MapWritable(MapWritable other)
          Copy constructor.
 
Method Summary
 void clear()
          
 boolean containsKey(Object key)
          
 boolean containsValue(Object value)
          
 Set<Map.Entry<Writable,Writable>> entrySet()
          
 boolean equals(Object obj)
          
 Writable get(Object key)
          
 int hashCode()
          
 boolean isEmpty()
          
 Set<Writable> keySet()
          
 Writable put(Writable key, Writable value)
          
 void putAll(Map<? extends Writable,? extends Writable> t)
          
 void readFields(DataInput in)
          Deserialize the fields of this object from in.
 Writable remove(Object key)
          
 int size()
          
 Collection<Writable> values()
          
 void write(DataOutput out)
          Serialize the fields of this object to out.
 
Methods inherited from class org.apache.hadoop.io.AbstractMapWritable
addToMap, copy, getClass, getConf, getId, setConf
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MapWritable

public MapWritable()
Default constructor.


MapWritable

public MapWritable(MapWritable other)
Copy constructor.

Parameters:
other - the map to copy from
Method Detail

clear

public void clear()

Specified by:
clear in interface Map<Writable,Writable>

containsKey

public boolean containsKey(Object key)

Specified by:
containsKey in interface Map<Writable,Writable>

containsValue

public boolean containsValue(Object value)

Specified by:
containsValue in interface Map<Writable,Writable>

entrySet

public Set<Map.Entry<Writable,Writable>> entrySet()

Specified by:
entrySet in interface Map<Writable,Writable>

equals

public boolean equals(Object obj)

Specified by:
equals in interface Map<Writable,Writable>
Overrides:
equals in class Object

get

public Writable get(Object key)

Specified by:
get in interface Map<Writable,Writable>

hashCode

public int hashCode()

Specified by:
hashCode in interface Map<Writable,Writable>
Overrides:
hashCode in class Object

isEmpty

public boolean isEmpty()

Specified by:
isEmpty in interface Map<Writable,Writable>

keySet

public Set<Writable> keySet()

Specified by:
keySet in interface Map<Writable,Writable>

put

public Writable put(Writable key,
                    Writable value)

Specified by:
put in interface Map<Writable,Writable>

putAll

public void putAll(Map<? extends Writable,? extends Writable> t)

Specified by:
putAll in interface Map<Writable,Writable>

remove

public Writable remove(Object key)

Specified by:
remove in interface Map<Writable,Writable>

size

public int size()

Specified by:
size in interface Map<Writable,Writable>

values

public Collection<Writable> values()

Specified by:
values in interface Map<Writable,Writable>

write

public void write(DataOutput out)
           throws IOException
Serialize the fields of this object to out.

Specified by:
write in interface Writable
Overrides:
write in class AbstractMapWritable
Parameters:
out - DataOuput to serialize this object into.
Throws:
IOException

readFields

public void readFields(DataInput in)
                throws IOException
Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:
readFields in interface Writable
Overrides:
readFields in class AbstractMapWritable
Parameters:
in - DataInput to deseriablize this object from.
Throws:
IOException


Copyright © 2013 Apache Software Foundation. All Rights Reserved.