Java Tuple2類代碼示例

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public void flatMap(String tweetJsonStr, Collector<Tuple2<String, Integer>> collector) throws Exception {
    JsonNode tweetJson = mapper.readTree(tweetJsonStr);
    JsonNode entities = tweetJson.get("entities");
    if (entities == null) return;

    JsonNode hashtags = entities.get("hashtags");
    if (hashtags == null) return;

    for (Iterator<JsonNode> iter = hashtags.getElements(); iter.hasNext();) {
        JsonNode node = iter.next();
        String hashtag = node.get("text").getTextValue();

        if (hashtag.matches("\\w+")) {
            collector.collect(new Tuple2<>(hashtag, 1));
        }
    }
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public void restoreState(List<Tuple2<Integer, BitSet>> state) throws Exception {
    if (state.isEmpty()) {
        Assert.fail("Function was restored without state - no checkpoint completed before.");
    }

    if (state.size() > 1) {
        Assert.fail("Function was restored with multiple states. unexpected scale-in");
    }

    Tuple2<Integer, BitSet> s = state.get(0);
    this.numElementsSoFar = s.f0;
    this.duplicateChecker.clear();
    this.duplicateChecker.or(s.f1);

    log.debug("IntSequenceExactlyOnceValidator was restored with {} elements", numElementsSoFar);
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public StreamState map(Tuple2<String, Message> input) throws Exception {

    StreamState currentState = internalState.value();

    if(currentState == null)
        currentState = new StreamState(input.f1.getId());

    currentState.appendMessage(input.f1);

    StreamState state = null;

    if(currentState.size() >= input.f1.getValues()) {
        currentState.isReadyForReduction = true;
        state = currentState;
        internalState.clear();
    } else {
        internalState.update(currentState);
    }

    return state;
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
public Tuple2<Event.EventType, State> randomTransition(Random rnd) {
	if (transitions.isEmpty()) {
		throw new RuntimeException("Cannot transition from state " + name);
	}
	float p = rnd.nextFloat();
	float mass = 0.0f;
	Transition transition = null;

	for (Transition t : transitions) {
		mass += t.prob;
		if (transition == null && p <= mass) {
			transition = t;
		}
	}
	return new Tuple2<>(transition.event, transition.targetState);
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
public static void main(String[] args) throws Exception {

		// set up the execution environment
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		// get input data
		DataSet<String> text = env.fromElements(
				"To be, or not to be,--that is the question:--",
				"Whether 'tis nobler in the mind to suffer",
				"The slings and arrows of outrageous fortune",
				"Or to take arms against a sea of troubles,"
				);

		DataSet<Tuple2<String, Integer>> counts =
				// split up the lines in pairs (2-tuples) containing: (word,1)
				text.flatMap(new LineSplitter())
				// group by the tuple field "0" and sum up tuple field "1"
				.groupBy(0)
				.sum(1);

		// execute and print result
		counts.print();

	}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public Tuple2<Integer, Boolean> map(TaxiRide taxiRide) throws Exception {
	float lon;
	float lat;
	final boolean isStart = taxiRide.isStart;
	if(isStart) {
		lon = taxiRide.startLon;
		lat = taxiRide.startLat;
	}
	else {
		lon = taxiRide.endLon;
		lat = taxiRide.endLat;
	}

	int gridId = GeoUtils.mapToGridCell(lon, lat);
	return Tuple2.of(gridId, isStart);
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public List<Tuple2<Integer, BitSet>> snapshotState(long checkpointId, long timestamp) throws Exception {
	log.info("IntSequenceExactlyOnceValidator - at checkpoint {} having {} elements, waitUntil {}",
			checkpointId, numElementsSoFar, waitUntil);

	// after we are done, we need to wait for two more checkpoint to complete
	// before finishing the program - that is to be on the safe side that
	// the sink also got the "commit" notification for all relevant checkpoints
	// and committed the data to pravega
	if (numElementsSoFar == numElementsTotal) {
		waitUntil--;
		if (waitUntil == 0) {
			throw new SuccessException();
		}
	}
	return Collections.singletonList(new Tuple2<>(numElementsSoFar, duplicateChecker));
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public void restoreState(List<Tuple2<Integer, BitSet>> state) throws Exception {
	if (state.isEmpty()) {
		Assert.fail("Function was restored without state - no checkpoint completed before.");
	}

	if (state.size() > 1) {
		Assert.fail("Function was restored with multiple states. unexpected scale-in");
	}

	Tuple2<Integer, BitSet> s = state.get(0);
	this.numElementsSoFar = s.f0;
	this.duplicateChecker.clear();
	this.duplicateChecker.or(s.f1);

	log.info("IntSequenceExactlyOnceValidator was restored with {} elements", numElementsSoFar);
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
public static void main(String[] args) throws Exception {
	StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

	DataStreamSource<Tuple2<String, Integer>> source = env.fromCollection(collection);

	CassandraSink.addSink(source)
		.setQuery(INSERT)
		.setClusterBuilder(new ClusterBuilder() {
			@Override
			protected Cluster buildCluster(Builder builder) {
				return builder.addContactPoint("127.0.0.1").build();
			}
		})
		.build();

	env.execute("WriteTupleIntoCassandra");
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public void flatMap(Tuple2<Long, String> tweet, Collector<Tuple3<Long, String, Float>> out) throws Exception {

    String text = tweet.f1;
    Set<String> posWords = PositiveWords.getWords();
    String[] words = text.split(" ");
    int numWords = words.length;
    int numPosWords = 0;
    for (String word : words) {
        if (posWords.contains(word))
            numPosWords++;
    }

    out.collect(new Tuple3<>(
            tweet.f0,
            tweet.f1,
            (float) numPosWords / numWords));

}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Test
public void testCorrectnessOfCrossWithHuge() throws Exception {
	/*
	 * check correctness of crossWithHuge (only correctness of result -> should be the same as with normal cross)
	 */

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	DataSet<Tuple5<Integer, Long, Integer, String, Long>> ds = CollectionDataSets.getSmall5TupleDataSet(env);
	DataSet<Tuple5<Integer, Long, Integer, String, Long>> ds2 = CollectionDataSets.getSmall5TupleDataSet(env);
	DataSet<Tuple2<Integer, String>> crossDs = ds.crossWithHuge(ds2).with(new Tuple5Cross());

	List<Tuple2<Integer, String>> result = crossDs.collect();

	String expected = "0,HalloHallo\n" +
			"1,HalloHallo Welt\n" +
			"2,HalloHallo Welt wie\n" +
			"1,Hallo WeltHallo\n" +
			"2,Hallo WeltHallo Welt\n" +
			"3,Hallo WeltHallo Welt wie\n" +
			"2,Hallo Welt wieHallo\n" +
			"3,Hallo Welt wieHallo Welt\n" +
			"4,Hallo Welt wieHallo Welt wie\n";

	compareResultAsTuples(result, expected);
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Override
public void processElement(
		String value,
		Context ctx,
		Collector<Tuple2<String, Integer>> out) throws Exception {
	// normalize and split the line
	String[] tokens = value.toLowerCase().split("\\W+");

	// emit the pairs
	for (String token : tokens) {
		if (token.length() > 5) {
			ctx.output(rejectedWordsTag, token);
		} else if (token.length() > 0) {
			out.collect(new Tuple2<>(token, 1));
		}
	}

}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Test
public void testAreCompatible4() throws Keys.IncompatibleKeysException {
	TypeInformation<Tuple3<String, Long, Integer>> t1 = new TupleTypeInfo<>(
		BasicTypeInfo.STRING_TYPE_INFO,
		BasicTypeInfo.LONG_TYPE_INFO,
		BasicTypeInfo.INT_TYPE_INFO
	);
	TypeInformation<PojoWithMultiplePojos> t2 = TypeExtractor.getForClass(PojoWithMultiplePojos.class);

	Keys.ExpressionKeys<Tuple3<String, Long, Integer>> ek1 = new Keys.ExpressionKeys<>(new int[]{2,0}, t1);
	Keys<PojoWithMultiplePojos> sk2 = new Keys.SelectorFunctionKeys<>(
		new KeySelector3(),
		t2,
		new TupleTypeInfo<Tuple2<Integer, String>>(BasicTypeInfo.INT_TYPE_INFO, BasicTypeInfo.STRING_TYPE_INFO)
	);

	Assert.assertTrue(sk2.areCompatible(ek1));
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
/**
 * Create a file with pre-determined String format of the form:
 * {@code fileIdx +": "+ sampleLine +" "+ lineNo}.
 * */
private static Tuple2<org.apache.hadoop.fs.Path, String> createFileAndFillWithData(
			String base, String fileName, int fileIdx, String sampleLine) throws IOException {

	assert (hdfs != null);

	final String fileRandSuffix = UUID.randomUUID().toString();

	org.apache.hadoop.fs.Path file = new org.apache.hadoop.fs.Path(base + "/" + fileName + fileRandSuffix);
	Assert.assertFalse(hdfs.exists(file));

	org.apache.hadoop.fs.Path tmp = new org.apache.hadoop.fs.Path(base + "/." + fileName + fileRandSuffix);
	FSDataOutputStream stream = hdfs.create(tmp);
	StringBuilder str = new StringBuilder();
	for (int i = 0; i < LINES_PER_FILE; i++) {
		String line = fileIdx + ": " + sampleLine + " " + i + "\n";
		str.append(line);
		stream.write(line.getBytes(ConfigConstants.DEFAULT_CHARSET));
	}
	stream.close();

	hdfs.rename(tmp, file);

	Assert.assertTrue("No result file present", hdfs.exists(file));
	return new Tuple2<>(file, str.toString());
}
 

import org.apache.flink.api.java.tuple.Tuple2; //導入依賴的package包/類
@Test
public void testSumOfInNeighborsNoValue() throws Exception {
	/*
	 * Get the sum of in-neighbor values
	 * times the edge weights for each vertex
        */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> verticesWithSum =
		graph.groupReduceOnNeighbors(new SumInNeighborsNoValue(), EdgeDirection.IN);
	List<Tuple2<Long, Long>> result = verticesWithSum.collect();

	expectedResult = "1,255\n" +
		"2,12\n" +
		"3,59\n" +
		"4,102\n" +
		"5,285\n";

	compareResultAsTuples(result, expectedResult);
}