/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.mrunit.mapreduce;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.Counters;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.map.WrappedMapper;
import org.apache.hadoop.mrunit.MapDriverBase;
import org.apache.hadoop.mrunit.mapreduce.mock.MockMapContext;
import org.apache.hadoop.mrunit.types.Pair;
/**
* Harness that allows you to test a Mapper instance. You provide the input
* key and value that should be sent to the Mapper, and outputs you expect to
* be sent by the Mapper to the collector for those inputs. By calling
* runTest(), the harness will deliver the input to the Mapper and will check
* its outputs against the expected results. This is designed to handle a
* single (k, v) -> (k, v)* case from the Mapper, representing a single unit
* test. Multiple input (k, v) pairs should go in separate unit tests.
*/
public class MapDriver<K1, V1, K2, V2> extends MapDriverBase<K1, V1, K2, V2> {
public static final Log LOG = LogFactory.getLog(MapDriver.class);
private Mapper<K1, V1, K2, V2> myMapper;
private Counters counters;
public MapDriver(final Mapper<K1, V1, K2, V2> m) {
myMapper = m;
counters = new Counters();
}
public MapDriver() {
counters = new Counters();
}
/**
* Set the Mapper instance to use with this test driver
*
* @param m the Mapper instance to use
*/
public void setMapper(Mapper<K1, V1, K2, V2> m) {
myMapper = m;
}
/** Sets the Mapper instance to use and returns self for fluent style */
public MapDriver<K1, V1, K2, V2> withMapper(Mapper<K1, V1, K2, V2> m) {
setMapper(m);
return this;
}
/**
* @return the Mapper object being used by this test
*/
public Mapper<K1, V1, K2, V2> getMapper() {
return myMapper;
}
/** @return the counters used in this test */
public Counters getCounters() {
return counters;
}
/** Sets the counters object to use for this test.
* @param ctrs The counters object to use.
*/
public void setCounters(final Counters ctrs) {
this.counters = ctrs;
}
/** Sets the counters to use and returns self for fluent style */
public MapDriver<K1, V1, K2, V2> withCounters(final Counters ctrs) {
setCounters(ctrs);
return this;
}
/**
* Identical to setInputKey() but with fluent programming style
*
* @return this
*/
public MapDriver<K1, V1, K2, V2> withInputKey(K1 key) {
setInputKey(key);
return this;
}
/**
* Identical to setInputValue() but with fluent programming style
*
* @param val
* @return this
*/
public MapDriver<K1, V1, K2, V2> withInputValue(V1 val) {
setInputValue(val);
return this;
}
/**
* Identical to setInput() but returns self for fluent programming style
*
* @return this
*/
public MapDriver<K1, V1, K2, V2> withInput(K1 key, V1 val) {
setInput(key, val);
return this;
}
/**
* Identical to setInput() but returns self for fluent programming style
*
* @param inputRecord
* @return this
*/
public MapDriver<K1, V1, K2, V2> withInput(Pair<K1, V1> inputRecord) {
setInput(inputRecord);
return this;
}
/**
* Works like addOutput(), but returns self for fluent style
*
* @param outputRecord
* @return this
*/
public MapDriver<K1, V1, K2, V2> withOutput(Pair<K2, V2> outputRecord) {
addOutput(outputRecord);
return this;
}
/**
* Functions like addOutput() but returns self for fluent programming
* style
*
* @return this
*/
public MapDriver<K1, V1, K2, V2> withOutput(K2 key, V2 val) {
addOutput(key, val);
return this;
}
/**
* Identical to setInputFromString, but with a fluent programming style
*
* @param input
* A string of the form "key \t val". Trims any whitespace.
* @return this
*/
public MapDriver<K1, V1, K2, V2> withInputFromString(String input) {
setInputFromString(input);
return this;
}
/**
* Identical to addOutputFromString, but with a fluent programming style
*
* @param output
* A string of the form "key \t val". Trims any whitespace.
* @return this
*/
public MapDriver<K1, V1, K2, V2> withOutputFromString(String output) {
addOutputFromString(output);
return this;
}
@Override
public List<Pair<K2, V2>> run() throws IOException {
List<Pair<K1, V1>> inputs = new ArrayList<Pair<K1, V1>>();
inputs.add(new Pair<K1, V1>(inputKey, inputVal));
try {
MockMapContext<K1, V1, K2, V2> context =
new MockMapContext<K1, V1, K2, V2>(configuration, inputs, getCounters());
myMapper.run(new WrappedMapper<K1, V1, K2, V2>().getMapContext(context));
return context.getOutputs();
} catch (InterruptedException ie) {
throw new IOException(ie);
}
}
@Override
public String toString() {
return "MapDriver (0.20+) (" + myMapper + ")";
}
/**
* @param configuration The configuration object that will given to the mapper
* associated with the driver
* @return this object for fluent coding
*/
public MapDriver<K1, V1, K2, V2> withConfiguration(Configuration configuration) {
setConfiguration(configuration);
return this;
}
}