org.apache.hadoop.mrunit
Class MapReduceDriver<K1,V1,K2 extends Comparable,V2,K3,V3>

java.lang.Object
  org.apache.hadoop.mrunit.TestDriver<K1,V1,K3,V3>
      org.apache.hadoop.mrunit.MapReduceDriverBase<K1,V1,K2,V2,K3,V3>
          org.apache.hadoop.mrunit.MapReduceDriver<K1,V1,K2,V2,K3,V3>

public class MapReduceDriver<K1,V1,K2 extends Comparable,V2,K3,V3>
extends MapReduceDriverBase<K1,V1,K2,V2,K3,V3>

Harness that allows you to test a Mapper and a Reducer instance together (along with an optional combiner). You provide the input key and value that should be sent to the Mapper, and outputs you expect to be sent by the Reducer to the collector for those inputs. By calling runTest(), the harness will deliver the input to the Mapper, feed the intermediate results to the Reducer (without checking them), and will check the Reducer's outputs against the expected results. This is designed to handle the (k, v)* -> (k, v)* case from the Mapper/Reducer pair, representing a single unit test. If a combiner is specified, then it will be run exactly once after the Mapper and before the Reducer.

Field Summary

static org.apache.commons.logging.Log

LOG

Fields inherited from class org.apache.hadoop.mrunit.MapReduceDriverBase

inputList, keyGroupComparator, keyValueOrderComparator

Fields inherited from class org.apache.hadoop.mrunit.TestDriver

configuration, expectedOutputs

Constructor Summary

MapReduceDriver()

MapReduceDriver(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m, org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r)

MapReduceDriver(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m, org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r, org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2> c)

Method Summary

org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2>	getCombiner()
org.apache.hadoop.mapred.Counters	getCounters()
org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2>	getMapper()
org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3>	getReducer()
static <K1,V1,K2 extends Comparable,V2,K3,V3> MapReduceDriver<K1,V1,K2,V2,K3,V3>	newMapReduceDriver() Returns a new MapReduceDriver without having to specify the generic types on the right hand side of the object create statement.
static <K1,V1,K2 extends Comparable,V2,K3,V3> MapReduceDriver<K1,V1,K2,V2,K3,V3>	newMapReduceDriver(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> mapper, org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> reducer) Returns a new MapReduceDriver without having to specify the generic types on the right hand side of the object create statement.
List<Pair<K3,V3>>	run() Runs the test but returns the result set instead of validating it (ignores any addOutput(), etc calls made before this)
void	setCombiner(org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2> c) Sets the reducer object to use as a combiner for this test
void	setCounters(org.apache.hadoop.mapred.Counters ctrs) Sets the counters object to use for this test.
void	setMapper(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m) Set the Mapper instance to use with this test driver
void	setReducer(org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r) Sets the reducer object to use for this test
String	toString()
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withCombiner(org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2> c) Identical to setCombiner(), but with fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withCounters(org.apache.hadoop.mapred.Counters ctrs) Sets the counters to use and returns self for fluent style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withInput(K1 key, V1 val) Identical to addInput() but returns self for fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withInput(Pair<K1,V1> input) Identical to addInput() but returns self for fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withInputFromString(String input) Identical to addInputFromString, but with a fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withKeyGroupingComparator(org.apache.hadoop.io.RawComparator<K2> groupingComparator) Identical to MapReduceDriverBase.setKeyGroupingComparator(RawComparator), but with a fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withKeyOrderComparator(org.apache.hadoop.io.RawComparator<K2> orderComparator) Identical to MapReduceDriverBase.setKeyOrderComparator(RawComparator), but with a fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withMapper(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m) Sets the Mapper instance to use and returns self for fluent style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withOutput(K3 key, V3 val) Functions like addOutput() but returns self for fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withOutput(Pair<K3,V3> outputRecord) Works like addOutput(), but returns self for fluent style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withOutputFromString(String output) Identical to addOutputFromString, but with a fluent programming style
MapReduceDriver<K1,V1,K2,V2,K3,V3>	withReducer(org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r) Identical to setReducer(), but with fluent programming style

Methods inherited from class org.apache.hadoop.mrunit.MapReduceDriverBase

addInput, addInput, addInputFromString, addOutput, addOutput, addOutputFromString, runTest, setKeyGroupingComparator, setKeyOrderComparator, shuffle

Methods inherited from class org.apache.hadoop.mrunit.TestDriver

formatValueList, getConfiguration, getExpectedOutputs, parseCommaDelimitedList, parseTabbedPair, resetOutput, setConfiguration, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG

public static final org.apache.commons.logging.Log LOG

Constructor Detail

MapReduceDriver

public MapReduceDriver(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m,
                       org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r)

MapReduceDriver

public MapReduceDriver(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m,
                       org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r,
                       org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2> c)

MapReduceDriver

public MapReduceDriver()

Method Detail

getCounters

public org.apache.hadoop.mapred.Counters getCounters()

Returns:

the counters used in this test

setCounters

public void setCounters(org.apache.hadoop.mapred.Counters ctrs)

Sets the counters object to use for this test.

Parameters:

ctrs - The counters object to use.

withCounters

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withCounters(org.apache.hadoop.mapred.Counters ctrs)

Sets the counters to use and returns self for fluent style

setMapper

public void setMapper(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m)

Set the Mapper instance to use with this test driver

Parameters:

m - the Mapper instance to use

withMapper

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withMapper(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> m)

Sets the Mapper instance to use and returns self for fluent style

getMapper

public org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> getMapper()

Returns:

the Mapper object being used by this test

setReducer

public void setReducer(org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r)

Sets the reducer object to use for this test

Parameters:

r - The reducer object to use

withReducer

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withReducer(org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> r)

Identical to setReducer(), but with fluent programming style

Parameters:

r - The Reducer to use

Returns:

this

getReducer

public org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> getReducer()

Returns:

the Reducer object being used for this test

setCombiner

public void setCombiner(org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2> c)

Sets the reducer object to use as a combiner for this test

Parameters:

c - The combiner object to use

withCombiner

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withCombiner(org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2> c)

Identical to setCombiner(), but with fluent programming style

Parameters:

c - The Combiner to use

Returns:

this

getCombiner

public org.apache.hadoop.mapred.Reducer<K2,V2,K2,V2> getCombiner()

Returns:

the Combiner object being used for this test

withInput

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withInput(K1 key,
                                                    V1 val)

Identical to addInput() but returns self for fluent programming style

Parameters:

key -

val -

Returns:

this

withInput

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withInput(Pair<K1,V1> input)

Identical to addInput() but returns self for fluent programming style

Parameters:

input - The (k, v) pair to add

Returns:

this

withOutput

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withOutput(Pair<K3,V3> outputRecord)

Works like addOutput(), but returns self for fluent style

Parameters:

outputRecord -

Returns:

this

withOutput

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withOutput(K3 key,
                                                     V3 val)

Functions like addOutput() but returns self for fluent programming style

Parameters:

key -

val -

Returns:

this

withInputFromString

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withInputFromString(String input)

Identical to addInputFromString, but with a fluent programming style

Parameters:

input - A string of the form "key \t val". Trims any whitespace.

Returns:

this

withOutputFromString

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withOutputFromString(String output)

Identical to addOutputFromString, but with a fluent programming style

Parameters:

output - A string of the form "key \t val". Trims any whitespace.

Returns:

this

run

public List<Pair<K3,V3>> run()
                      throws IOException

Description copied from class: TestDriver

Runs the test but returns the result set instead of validating it (ignores any addOutput(), etc calls made before this)

Specified by:

run in class MapReduceDriverBase<K1,V1,K2 extends Comparable,V2,K3,V3>

Returns:

the list of (k, v) pairs returned as output from the test

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

withKeyGroupingComparator

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withKeyGroupingComparator(org.apache.hadoop.io.RawComparator<K2> groupingComparator)

Identical to MapReduceDriverBase.setKeyGroupingComparator(RawComparator), but with a fluent programming style

Parameters:

groupingComparator - Comparator to use in the shuffle stage for key grouping

Returns:

this

withKeyOrderComparator

public MapReduceDriver<K1,V1,K2,V2,K3,V3> withKeyOrderComparator(org.apache.hadoop.io.RawComparator<K2> orderComparator)

Identical to MapReduceDriverBase.setKeyOrderComparator(RawComparator), but with a fluent programming style

Parameters:

orderComparator - Comparator to use in the shuffle stage for key value ordering

Returns:

this

newMapReduceDriver

public static <K1,V1,K2 extends Comparable,V2,K3,V3> MapReduceDriver<K1,V1,K2,V2,K3,V3> newMapReduceDriver()

Returns a new MapReduceDriver without having to specify the generic types on the right hand side of the object create statement.

Parameters:

mapper - passed to MapReduceDriver constructor

reducer - passed to MapReduceDriver constructor

Returns:

new MapReduceDriver

newMapReduceDriver

public static <K1,V1,K2 extends Comparable,V2,K3,V3> MapReduceDriver<K1,V1,K2,V2,K3,V3> newMapReduceDriver(org.apache.hadoop.mapred.Mapper<K1,V1,K2,V2> mapper,
                                                                                                           org.apache.hadoop.mapred.Reducer<K2,V2,K3,V3> reducer)

Returns a new MapReduceDriver without having to specify the generic types on the right hand side of the object create statement.

Parameters:

mapper - passed to MapReduceDriver constructor

reducer - passed to MapReduceDriver constructor

Returns:

new MapReduceDriver