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TimeWindow有getStart()和getEnd()方法，参见示例代码： StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment(); env.setParallelism(PARALLELISM); env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime); env.enableCheckpointing(100); env.setRestartStrategy(RestartStrategies.fixedDelayRestart(3, 0)); env.getConfig().disableSysoutLogging(); env.addSource(new FailingSource(numKeys, numElementsPerKey, numElementsPerKey / 3)) .rebalance() .timeWindowAll(Time.of(windowSize, MILLISECONDS)) .apply(new RichAllWindowFunction, Tuple4, TimeWindow>() { private boolean open = false; @Override public void open(Configuration parameters) { assertEquals(1, getRuntimeContext().getNumberOfParallelSubtasks()); open = true; } @Override public void apply( TimeWindow window, Iterable> values, Collector> out) { // validate that the function has been opened properly assertTrue(open); int sum = 0; long key = -1; for (Tuple2 value : values) { sum += value.f1.value; key = value.f0; } out.collect(new Tuple4<>(key, window.getStart(), window.getEnd(), new IntType(sum))); } }) .addSink(new ValidatingSink(numKeys, numElementsPerKey / windowSize)).setParallelism(1); env.execute('Tumbling Window Test'); TimeWindow有getStart()和getEnd()方法。

如果使用DataStream API可参见flink的WordCount（org.apache.flink.streaming.examples.wordcount.WordCount）示例代码： public class WordCount { // ************************************************************************* // PROGRAM // ************************************************************************* public static void main(String[] args) throws Exception { // Checking input parameters final ParameterTool params = ParameterTool.fromArgs(args); // set up the execution environment final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment(); // make parameters available in the web interface env.getConfig().setGlobalJobParameters(params); // get input data DataStream text; if (params.has('input')) { // read the text file from given input path text = env.readTextFile(params.get('input')); } else { System.out.println('Executing WordCount example with default input data set.'); System.out.println('Use --input to specify file input.'); // get default test text data text = env.fromElements(WordCountData.WORDS); } DataStream> counts = // split up the lines in pairs (2-tuples) containing: (word,1) text.flatMap(new Tokenizer()) // group by the tuple field '0' and sum up tuple field '1' .keyBy(0).sum(1); // emit result if (params.has('output')) { counts.writeAsText(params.get('output')); } else { System.out.println('Printing result to stdout. Use --output to specify output path.'); counts.print(); } // execute program env.execute('Streaming WordCount'); } // ************************************************************************* // USER FUNCTIONS // ************************************************************************* /** * Implements the string tokenizer that splits sentences into words as a * user-defined FlatMapFunction. The function takes a line (String) and * splits it into multiple pairs in the form of '(word,1)' ({@code Tuple2}). */ public static final class Tokenizer implements FlatMapFunction> { @Override public void flatMap(String value, Collector> out) { // normalize and split the line String[] tokens = value.toLowerCase().split('\\W+'); // emit the pairs for (String token : tokens) { if (token.length() > 0) { out.collect(new Tuple2<>(token, 1)); } } } } }

我理解你的需求实际是要求window的size是可变的，如果用DataStream，可以通过自定义一个WindowAssigner实现（见方法DataStream.windowAll(WindowAssigner assigner)），基于time的自定义的WindowAssigner实现可参见类TumblingProcessingTimeWindows或TumblingEventTimeWindows。

贴出来的异常是现象，不是root cause，需要更详情的日志才好判断。

从checkpoint的metadata file手动恢复state，路径需要指定到具体的某个checkpoint， 即 /path/{job-id}/chk-{i}。

用RocksDBStateBackend的话使用增量checkpoint，设置配置项 state.backend.incremental 为 true。