flink的state

 public static void main(String[] args) throws Exception{
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);

        // 来自app的支付日志
        SingleOutputStreamOperator<Tuple3<String, String, Long>> appStream = env.fromElements(
                Tuple3.of("order-1", "app", 1000L),
                Tuple3.of("order-2", "app", 4000L)
        ).assignTimestampsAndWatermarks(WatermarkStrategy.<Tuple3<String, String, Long>>forMonotonousTimestamps()
                .withTimestampAssigner(new SerializableTimestampAssigner<Tuple3<String, String, Long>>() {
                    @Override
                    public long extractTimestamp(Tuple3<String, String, Long> element, long recordTimestamp) {
                        return element.f2;
                    }
                })
        );

        // 来自第三方支付平台的支付日志
        SingleOutputStreamOperator<Tuple4<String, String, String, Long>> thirdpartStream = env.fromElements(
                Tuple4.of("order-1", "third-party", "success", 3000L),
                Tuple4.of("order-3", "third-party", "success", 4000L)
        ).assignTimestampsAndWatermarks(WatermarkStrategy.<Tuple4<String, String, String, Long>>forMonotonousTimestamps()
                .withTimestampAssigner(new SerializableTimestampAssigner<Tuple4<String, String, String, Long>>() {
                    @Override
                    public long extractTimestamp(Tuple4<String, String, String, Long> element, long recordTimestamp) {
                        return element.f3;
                    }
                })
        );

        // 检测同一支付单在两条流中是否匹配，不匹配就报警
        appStream.connect(thirdpartStream)
                .keyBy(data -> data.f0, data -> data.f0)
                .process(new OrderMatchResult())
                .print();

        env.execute();
    }

    // 自定义实现CoProcessFunction
    public static class OrderMatchResult extends CoProcessFunction<Tuple3<String, String, Long>, Tuple4<String, String, String, Long>, String>{
        // 定义状态变量，用来保存已经到达的事件
        private ValueState<Tuple3<String, String, Long>> appEventState;
        private ValueState<Tuple4<String, String, String, Long>> thirdPartyEventState;

        @Override
        public void open(Configuration parameters) throws Exception {
            appEventState = getRuntimeContext().getState(
                    new ValueStateDescriptor<Tuple3<String, String, Long>>("app-event", Types.TUPLE(Types.STRING, Types.STRING, Types.LONG))
            );

            thirdPartyEventState = getRuntimeContext().getState(
                    new ValueStateDescriptor<Tuple4<String, String, String, Long>>("thirdparty-event", Types.TUPLE(Types.STRING, Types.STRING, Types.STRING,Types.LONG))
            );
        }

        @Override
        public void processElement1(Tuple3<String, String, Long> value, Context ctx, Collector<String> out) throws Exception {

            // 看另一条流中事件是否来过
            if (thirdPartyEventState.value() != null){
                out.collect("对账成功：" + value + "  " + thirdPartyEventState.value());
                // 清空状态
                thirdPartyEventState.clear();
            } else {
                // 更新状态
                appEventState.update(value);
                // 注册一个5秒后的定时器，开始等待另一条流的事件
                ctx.timerService().registerEventTimeTimer(value.f2 + 5000L);
            }
        }

        @Override
        public void processElement2(Tuple4<String, String, String, Long> value, Context ctx, Collector<String> out) throws Exception {
            if (appEventState.value() != null){
                out.collect("对账成功：" + appEventState.value() + "  " + value);
                // 清空状态
                appEventState.clear();
            } else {
                // 更新状态
                thirdPartyEventState.update(value);
                // 注册一个5秒后的定时器，开始等待另一条流的事件
                ctx.timerService().registerEventTimeTimer(value.f3 + 5000L);
            }
        }

        @Override
        public void onTimer(long timestamp, OnTimerContext ctx, Collector<String> out) throws Exception {
            // 定时器触发，判断状态，如果某个状态不为空，说明另一条流中事件没来
            if (appEventState.value() != null) {
                out.collect("对账失败：" + appEventState.value() + "  " + "第三方支付平台信息未到");
            }
            if (thirdPartyEventState.value() != null) {
                out.collect("对账失败：" + thirdPartyEventState.value() + "  " + "app信息未到");
            }
            appEventState.clear();
            thirdPartyEventState.clear();
        }
    }}

　　该例子使用了id相连，使用了

.keyBy(data -> data.f0, data -> data.f0)
和

private ValueState<Tuple3<String, String, Long>> appEventState;
private ValueState<Tuple4<String, String, String, Long>> thirdPartyEventState;

每次核对上的话 就把clear删除
一直不遇到相同的定时删除