下面列出了怎么用org.apache.hadoop.mapreduce.task.ReduceContextImpl的API类实例代码及写法，或者点击链接到github查看源代码。
@Override
public void open(int taskNumber, int numTasks) throws IOException {
super.open(taskNumber, numTasks);
synchronized (OPEN_MULTIPLE_MUTEX) {
try {
TaskInputOutputContext taskInputOutputContext = new ReduceContextImpl(configuration,
context.getTaskAttemptID(), new InputIterator(), new GenericCounter(), new GenericCounter(),
recordWriter, outputCommitter, new DummyReporter(), null,
BytesWritable.class, BytesWritable.class);
this.writer = new MultipleOutputs(taskInputOutputContext);
} catch (InterruptedException e) {
throw new IOException("Could not create MultipleOutputs.", e);
}
}
}
@SuppressWarnings("unchecked")
protected static <INKEY,INVALUE,OUTKEY,OUTVALUE>
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
createReduceContext(org.apache.hadoop.mapreduce.Reducer
<INKEY,INVALUE,OUTKEY,OUTVALUE> reducer,
Configuration job,
org.apache.hadoop.mapreduce.TaskAttemptID taskId,
RawKeyValueIterator rIter,
org.apache.hadoop.mapreduce.Counter inputKeyCounter,
org.apache.hadoop.mapreduce.Counter inputValueCounter,
org.apache.hadoop.mapreduce.RecordWriter<OUTKEY,OUTVALUE> output,
org.apache.hadoop.mapreduce.OutputCommitter committer,
org.apache.hadoop.mapreduce.StatusReporter reporter,
RawComparator<INKEY> comparator,
Class<INKEY> keyClass, Class<INVALUE> valueClass
) throws IOException, InterruptedException {
org.apache.hadoop.mapreduce.ReduceContext<INKEY, INVALUE, OUTKEY, OUTVALUE>
reduceContext =
new ReduceContextImpl<INKEY, INVALUE, OUTKEY, OUTVALUE>(job, taskId,
rIter,
inputKeyCounter,
inputValueCounter,
output,
committer,
reporter,
comparator,
keyClass,
valueClass);
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
reducerContext =
new WrappedReducer<INKEY, INVALUE, OUTKEY, OUTVALUE>().getReducerContext(
reduceContext);
return reducerContext;
}
@SuppressWarnings("unchecked")
protected static <INKEY,INVALUE,OUTKEY,OUTVALUE>
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
createReduceContext(org.apache.hadoop.mapreduce.Reducer
<INKEY,INVALUE,OUTKEY,OUTVALUE> reducer,
Configuration job,
org.apache.hadoop.mapreduce.TaskAttemptID taskId,
RawKeyValueIterator rIter,
org.apache.hadoop.mapreduce.Counter inputKeyCounter,
org.apache.hadoop.mapreduce.Counter inputValueCounter,
org.apache.hadoop.mapreduce.RecordWriter<OUTKEY,OUTVALUE> output,
org.apache.hadoop.mapreduce.OutputCommitter committer,
org.apache.hadoop.mapreduce.StatusReporter reporter,
RawComparator<INKEY> comparator,
Class<INKEY> keyClass, Class<INVALUE> valueClass
) throws IOException, InterruptedException {
org.apache.hadoop.mapreduce.ReduceContext<INKEY, INVALUE, OUTKEY, OUTVALUE>
reduceContext =
new ReduceContextImpl<INKEY, INVALUE, OUTKEY, OUTVALUE>(job, taskId,
rIter,
inputKeyCounter,
inputValueCounter,
output,
committer,
reporter,
comparator,
keyClass,
valueClass);
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
reducerContext =
new WrappedReducer<INKEY, INVALUE, OUTKEY, OUTVALUE>().getReducerContext(
reduceContext);
return reducerContext;
}
@Test (timeout=3000)
public void testLoadJobLoadReducer() throws Exception {
LoadJob.LoadReducer test = new LoadJob.LoadReducer();
Configuration conf = new Configuration();
conf.setInt(JobContext.NUM_REDUCES, 2);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(FileOutputFormat.COMPRESS, true);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(MRJobConfig.MAP_OUTPUT_COMPRESS, true);
TaskAttemptID taskid = new TaskAttemptID();
RawKeyValueIterator input = new FakeRawKeyValueIterator();
Counter counter = new GenericCounter();
Counter inputValueCounter = new GenericCounter();
LoadRecordWriter output = new LoadRecordWriter();
OutputCommitter committer = new CustomOutputCommitter();
StatusReporter reporter = new DummyReporter();
RawComparator<GridmixKey> comparator = new FakeRawComparator();
ReduceContext<GridmixKey, GridmixRecord, NullWritable, GridmixRecord> reduceContext = new ReduceContextImpl<GridmixKey, GridmixRecord, NullWritable, GridmixRecord>(
conf, taskid, input, counter, inputValueCounter, output, committer,
reporter, comparator, GridmixKey.class, GridmixRecord.class);
// read for previous data
reduceContext.nextKeyValue();
org.apache.hadoop.mapreduce.Reducer<GridmixKey, GridmixRecord, NullWritable, GridmixRecord>.Context context = new WrappedReducer<GridmixKey, GridmixRecord, NullWritable, GridmixRecord>()
.getReducerContext(reduceContext);
// test.setup(context);
test.run(context);
// have been readed 9 records (-1 for previous)
assertEquals(9, counter.getValue());
assertEquals(10, inputValueCounter.getValue());
assertEquals(1, output.getData().size());
GridmixRecord record = output.getData().values().iterator()
.next();
assertEquals(1593, record.getSize());
}
@Test (timeout=3000)
public void testSleepReducer() throws Exception {
Configuration conf = new Configuration();
conf.setInt(JobContext.NUM_REDUCES, 2);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(FileOutputFormat.COMPRESS, true);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(MRJobConfig.MAP_OUTPUT_COMPRESS, true);
TaskAttemptID taskId = new TaskAttemptID();
RawKeyValueIterator input = new FakeRawKeyValueReducerIterator();
Counter counter = new GenericCounter();
Counter inputValueCounter = new GenericCounter();
RecordWriter<NullWritable, NullWritable> output = new LoadRecordReduceWriter();
OutputCommitter committer = new CustomOutputCommitter();
StatusReporter reporter = new DummyReporter();
RawComparator<GridmixKey> comparator = new FakeRawComparator();
ReduceContext<GridmixKey, NullWritable, NullWritable, NullWritable> reducecontext = new ReduceContextImpl<GridmixKey, NullWritable, NullWritable, NullWritable>(
conf, taskId, input, counter, inputValueCounter, output, committer,
reporter, comparator, GridmixKey.class, NullWritable.class);
org.apache.hadoop.mapreduce.Reducer<GridmixKey, NullWritable, NullWritable, NullWritable>.Context context = new WrappedReducer<GridmixKey, NullWritable, NullWritable, NullWritable>()
.getReducerContext(reducecontext);
SleepReducer test = new SleepReducer();
long start = System.currentTimeMillis();
test.setup(context);
long sleeper = context.getCurrentKey().getReduceOutputBytes();
// status has been changed
assertEquals("Sleeping... " + sleeper + " ms left", context.getStatus());
// should sleep 0.9 sec
assertTrue(System.currentTimeMillis() >= (start + sleeper));
test.cleanup(context);
// status has been changed again
assertEquals("Slept for " + sleeper, context.getStatus());
}
@Test (timeout=3000)
public void testLoadJobLoadReducer() throws Exception {
LoadJob.LoadReducer test = new LoadJob.LoadReducer();
Configuration conf = new Configuration();
conf.setInt(JobContext.NUM_REDUCES, 2);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(FileOutputFormat.COMPRESS, true);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(MRJobConfig.MAP_OUTPUT_COMPRESS, true);
TaskAttemptID taskid = new TaskAttemptID();
RawKeyValueIterator input = new FakeRawKeyValueIterator();
Counter counter = new GenericCounter();
Counter inputValueCounter = new GenericCounter();
LoadRecordWriter output = new LoadRecordWriter();
OutputCommitter committer = new CustomOutputCommitter();
StatusReporter reporter = new DummyReporter();
RawComparator<GridmixKey> comparator = new FakeRawComparator();
ReduceContext<GridmixKey, GridmixRecord, NullWritable, GridmixRecord> reduceContext = new ReduceContextImpl<GridmixKey, GridmixRecord, NullWritable, GridmixRecord>(
conf, taskid, input, counter, inputValueCounter, output, committer,
reporter, comparator, GridmixKey.class, GridmixRecord.class);
// read for previous data
reduceContext.nextKeyValue();
org.apache.hadoop.mapreduce.Reducer<GridmixKey, GridmixRecord, NullWritable, GridmixRecord>.Context context = new WrappedReducer<GridmixKey, GridmixRecord, NullWritable, GridmixRecord>()
.getReducerContext(reduceContext);
// test.setup(context);
test.run(context);
// have been readed 9 records (-1 for previous)
assertEquals(9, counter.getValue());
assertEquals(10, inputValueCounter.getValue());
assertEquals(1, output.getData().size());
GridmixRecord record = output.getData().values().iterator()
.next();
assertEquals(1593, record.getSize());
}
@Test (timeout=3000)
public void testSleepReducer() throws Exception {
Configuration conf = new Configuration();
conf.setInt(JobContext.NUM_REDUCES, 2);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(FileOutputFormat.COMPRESS, true);
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
conf.setBoolean(MRJobConfig.MAP_OUTPUT_COMPRESS, true);
TaskAttemptID taskId = new TaskAttemptID();
RawKeyValueIterator input = new FakeRawKeyValueReducerIterator();
Counter counter = new GenericCounter();
Counter inputValueCounter = new GenericCounter();
RecordWriter<NullWritable, NullWritable> output = new LoadRecordReduceWriter();
OutputCommitter committer = new CustomOutputCommitter();
StatusReporter reporter = new DummyReporter();
RawComparator<GridmixKey> comparator = new FakeRawComparator();
ReduceContext<GridmixKey, NullWritable, NullWritable, NullWritable> reducecontext = new ReduceContextImpl<GridmixKey, NullWritable, NullWritable, NullWritable>(
conf, taskId, input, counter, inputValueCounter, output, committer,
reporter, comparator, GridmixKey.class, NullWritable.class);
org.apache.hadoop.mapreduce.Reducer<GridmixKey, NullWritable, NullWritable, NullWritable>.Context context = new WrappedReducer<GridmixKey, NullWritable, NullWritable, NullWritable>()
.getReducerContext(reducecontext);
SleepReducer test = new SleepReducer();
long start = System.currentTimeMillis();
test.setup(context);
long sleeper = context.getCurrentKey().getReduceOutputBytes();
// status has been changed
assertEquals("Sleeping... " + sleeper + " ms left", context.getStatus());
// should sleep 0.9 sec
assertTrue(System.currentTimeMillis() >= (start + sleeper));
test.cleanup(context);
// status has been changed again
assertEquals("Slept for " + sleeper, context.getStatus());
}
protected static <INKEY,INVALUE,OUTKEY,OUTVALUE>
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
createReduceContext(org.apache.hadoop.mapreduce.Reducer
<INKEY,INVALUE,OUTKEY,OUTVALUE> reducer,
Configuration job,
TaskAttemptID taskId,
final TezRawKeyValueIterator rIter,
org.apache.hadoop.mapreduce.Counter inputKeyCounter,
org.apache.hadoop.mapreduce.Counter inputValueCounter,
org.apache.hadoop.mapreduce.RecordWriter<OUTKEY,OUTVALUE> output,
org.apache.hadoop.mapreduce.OutputCommitter committer,
org.apache.hadoop.mapreduce.StatusReporter reporter,
RawComparator<INKEY> comparator,
Class<INKEY> keyClass, Class<INVALUE> valueClass
) throws IOException, InterruptedException {
RawKeyValueIterator r =
new RawKeyValueIterator() {
@Override
public boolean next() throws IOException {
return rIter.next();
}
@Override
public DataInputBuffer getValue() throws IOException {
return rIter.getValue();
}
@Override
public Progress getProgress() {
return rIter.getProgress();
}
@Override
public DataInputBuffer getKey() throws IOException {
return rIter.getKey();
}
@Override
public void close() throws IOException {
rIter.close();
}
};
org.apache.hadoop.mapreduce.ReduceContext<INKEY, INVALUE, OUTKEY, OUTVALUE>
reduceContext =
new ReduceContextImpl<INKEY, INVALUE, OUTKEY, OUTVALUE>(
job,
taskId,
r,
inputKeyCounter,
inputValueCounter,
output,
committer,
reporter,
comparator,
keyClass,
valueClass);
if (LOG.isDebugEnabled()) {
LOG.debug("Using key class: " + keyClass
+ ", valueClass: " + valueClass);
}
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
reducerContext =
new WrappedReducer<INKEY, INVALUE, OUTKEY, OUTVALUE>().getReducerContext(
reduceContext);
return reducerContext;
}
private static <KEYIN, VALUEIN, KEYOUT, VALUEOUT> org.apache.hadoop.mapreduce.Reducer<KEYIN, VALUEIN, KEYOUT, VALUEOUT>.Context createReduceContext(
Configuration conf,
TaskAttemptID mrTaskAttemptID,
final TezRawKeyValueIterator rawIter,
Counter combineInputKeyCounter,
Counter combineInputValueCounter,
RecordWriter<KEYOUT, VALUEOUT> recordWriter,
MRTaskReporter reporter,
RawComparator<KEYIN> comparator,
Class<KEYIN> keyClass,
Class<VALUEIN> valClass) throws InterruptedException, IOException {
RawKeyValueIterator r = new RawKeyValueIterator() {
@Override
public boolean next() throws IOException {
return rawIter.next();
}
@Override
public DataInputBuffer getValue() throws IOException {
return rawIter.getValue();
}
@Override
public Progress getProgress() {
return rawIter.getProgress();
}
@Override
public DataInputBuffer getKey() throws IOException {
return rawIter.getKey();
}
@Override
public void close() throws IOException {
rawIter.close();
}
};
ReduceContext<KEYIN, VALUEIN, KEYOUT, VALUEOUT> rContext = new ReduceContextImpl<KEYIN, VALUEIN, KEYOUT, VALUEOUT>(
conf, mrTaskAttemptID, r, combineInputKeyCounter,
combineInputValueCounter, recordWriter, null, reporter, comparator,
keyClass, valClass);
org.apache.hadoop.mapreduce.Reducer<KEYIN, VALUEIN, KEYOUT, VALUEOUT>.Context reducerContext = new WrappedReducer<KEYIN, VALUEIN, KEYOUT, VALUEOUT>()
.getReducerContext(rContext);
return reducerContext;
}
protected static <INKEY,INVALUE,OUTKEY,OUTVALUE>
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
createReduceContext(org.apache.hadoop.mapreduce.Reducer
<INKEY,INVALUE,OUTKEY,OUTVALUE> reducer,
Configuration job,
TaskAttemptID taskId,
final TezRawKeyValueIterator rIter,
org.apache.hadoop.mapreduce.Counter inputKeyCounter,
org.apache.hadoop.mapreduce.Counter inputValueCounter,
org.apache.hadoop.mapreduce.RecordWriter<OUTKEY,OUTVALUE> output,
org.apache.hadoop.mapreduce.OutputCommitter committer,
org.apache.hadoop.mapreduce.StatusReporter reporter,
RawComparator<INKEY> comparator,
Class<INKEY> keyClass, Class<INVALUE> valueClass
) throws IOException, InterruptedException {
RawKeyValueIterator r =
new RawKeyValueIterator() {
@Override
public boolean next() throws IOException {
return rIter.next();
}
@Override
public DataInputBuffer getValue() throws IOException {
return rIter.getValue();
}
@Override
public Progress getProgress() {
return rIter.getProgress();
}
@Override
public DataInputBuffer getKey() throws IOException {
return rIter.getKey();
}
@Override
public void close() throws IOException {
rIter.close();
}
};
org.apache.hadoop.mapreduce.ReduceContext<INKEY, INVALUE, OUTKEY, OUTVALUE>
reduceContext =
new ReduceContextImpl<INKEY, INVALUE, OUTKEY, OUTVALUE>(
job,
taskId,
r,
inputKeyCounter,
inputValueCounter,
output,
committer,
reporter,
comparator,
keyClass,
valueClass);
if (LOG.isDebugEnabled()) {
LOG.debug("Using key class: " + keyClass
+ ", valueClass: " + valueClass);
}
org.apache.hadoop.mapreduce.Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE>.Context
reducerContext =
new WrappedReducer<INKEY, INVALUE, OUTKEY, OUTVALUE>().getReducerContext(
reduceContext);
return reducerContext;
}
private static <KEYIN, VALUEIN, KEYOUT, VALUEOUT> org.apache.hadoop.mapreduce.Reducer<KEYIN, VALUEIN, KEYOUT, VALUEOUT>.Context createReduceContext(
Configuration conf,
TaskAttemptID mrTaskAttemptID,
final TezRawKeyValueIterator rawIter,
Counter combineInputRecordsCounter,
Counter combineOutputRecordsCounter,
RecordWriter<KEYOUT, VALUEOUT> recordWriter,
MRTaskReporter reporter,
RawComparator<KEYIN> comparator,
Class<KEYIN> keyClass,
Class<VALUEIN> valClass) throws InterruptedException, IOException {
RawKeyValueIterator r = new RawKeyValueIterator() {
@Override
public boolean next() throws IOException {
return rawIter.next();
}
@Override
public DataInputBuffer getValue() throws IOException {
return rawIter.getValue();
}
@Override
public Progress getProgress() {
return rawIter.getProgress();
}
@Override
public DataInputBuffer getKey() throws IOException {
return rawIter.getKey();
}
@Override
public void close() throws IOException {
rawIter.close();
}
};
ReduceContext<KEYIN, VALUEIN, KEYOUT, VALUEOUT> rContext = new ReduceContextImpl<KEYIN, VALUEIN, KEYOUT, VALUEOUT>(
conf, mrTaskAttemptID, r, null,
combineInputRecordsCounter, recordWriter, null, reporter, comparator,
keyClass, valClass);
org.apache.hadoop.mapreduce.Reducer<KEYIN, VALUEIN, KEYOUT, VALUEOUT>.Context reducerContext = new WrappedReducer<KEYIN, VALUEIN, KEYOUT, VALUEOUT>()
.getReducerContext(rContext);
return reducerContext;
}