## org.apache.hadoop.mapreduce
Class Counter

    java.lang.Object
      org.apache.hadoop.mapreduce.Counter

All Implemented Interfaces:
  Writable

Direct Known Subclasses:
  Counters.Counter

    public class Counter

extends Object
implements Writable

A named counter that tracks the progress of a map/reduce job.

`Counters` represent global counters, defined either by the Map-Reduce framework or applications. Each `Counter` is named by an `Enum` and has a long for the value.

`Counters` are bunched into Groups, each comprising of counters from a particular `Enum` class.

Constructor Summary
`protected` `Counter()`
`protected` `Counter(String name, String displayName)`

Method Summary
`boolean` `equals(Object genericRight)`
`String` `getDisplayName()` Get the name of the counter.
`String` `getName()`
`long` `getValue()` What is the current value of this counter?
`int` `hashCode()`
`void` `increment(long incr)` Increment this counter by the given value
`void` `readFields(DataInput in)` Read the binary representation of the counter
`protected void` `setDisplayName(String displayName)` Deprecated.
`void` `setValue(long value)` Set this counter by the given value
`void` `write(DataOutput out)` Write the binary representation of the counter

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

Constructor Detail

### Counter

    protected Counter()

### Counter

    protected Counter(String name,
                      String displayName)

Method Detail

### setDisplayName

    @Deprecated
    protected void setDisplayName(String displayName)

  Deprecated.

### readFields

    public void readFields(DataInput in)
                    throws IOException

  Read the binary representation of the counter

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

### write

    public void write(DataOutput out)
               throws IOException

  Write the binary representation of the counter

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

### getName

    public String getName()

### getDisplayName

    public String getDisplayName()

  Get the name of the counter.

  Returns:
    the user facing name of the counter

### getValue

    public long getValue()

  What is the current value of this counter?

  Returns:
    the current value

### setValue

    public void setValue(long value)

  Set this counter by the given value

  Parameters:
    `value` - the value to set

### increment

    public void increment(long incr)

  Increment this counter by the given value

  Parameters:
    `incr` - the value to increase this counter by

### equals

    public boolean equals(Object genericRight)

  Overrides:
    `equals` in class `Object`

### hashCode

    public int hashCode()

  Overrides:
    `hashCode` in class `Object`

Copyright © 2009 The Apache Software Foundation