Question

我使用以下方法在镶木地板文件中写入数据：

static void toParquet() {
        String schema = "message spark_schema {\n  optional binary stringField (UTF8);\n  optional INT96  createdAt;\n}";
        MessageType readSchema = MessageTypeParser.parseMessageType(schema);
        Configuration configuration = new Configuration();
        GroupWriteSupport.setSchema(readSchema, configuration);
        SimpleGroupFactory sfg = new SimpleGroupFactory(readSchema);
        Path file = new Path("/home/user/data-" + System.currentTimeMillis() + ".parquet");
        try {
            ParquetWriter<Group> writer = new ParquetWriter<Group>(file, new GroupWriteSupport(), CompressionCodecName.UNCOMPRESSED, 1024, 1024, 512,
                    true, false, ParquetProperties.WriterVersion.PARQUET_1_0, configuration);

            for (int i = 0; i < 10000; ++i) {
                writer.write(sfg.newGroup().append("stringField", "abc").append("createdAt", String.valueOf(System.currentTimeMillis())));

            }
            writer.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

但它给了我以下例外：

java.lang.IllegalArgumentException：固定二进制大小13没有匹配字段类型长度12 at org.apache.parquet.column.values.plain.FixedLenByteArrayPlainValuesWriter.writeBytes（FixedLenByteArrayPlainValuesWriter.java:53）在 org.apache.parquet.column.values.dictionary.DictionaryValuesWriter $ PlainFixedLenArrayDictionaryValuesWriter.createDictionaryPage（DictionaryValuesWriter.java:324）在 org.apache.parquet.column.values.fallback.FallbackValuesWriter.createDictionaryPage（FallbackValuesWriter.java:102）在 org.apache.parquet.column.impl.ColumnWriterV1.flush（ColumnWriterV1.java:242）在 org.apache.parquet.column.impl.ColumnWriteStoreV1.flush（ColumnWriteStoreV1.java:126）在 org.apache.parquet.hadoop.InternalParquetRecordWriter.flushRowGroupToStore（InternalParquetRecordWriter.java:164）在 org.apache.parquet.hadoop.InternalParquetRecordWriter.checkBlockSizeReached（InternalParquetRecordWriter.java:141）在 org.apache.parquet.hadoop.InternalParquetRecordWriter.write（InternalParquetRecordWriter.java:123）在 org.apache.parquet.hadoop.ParquetWriter.write（ParquetWriter.java:288）在com.app.test.SimpleParquet.toParquet（SimpleParquet.java:498）at com.app.test.SimpleParquet.main（SimpleParquet.java:63）

由于System.currentTimeMillis（）给出13字节值，epoc时间为10字节，如何为当前时间戳提供int96值，这是一个固定长度的12字节数组。

我找到了一些线程，他们说时间戳是julian日和纳秒的时间组合，我如何将当前时间戳转换为这种格式？

Answer 1

下面的代码对我有用，其中我已经计算了NanoTime，然后在其上调用toBinary函数。

public static NanoTime getNanoTime(String time) {
        Timestamp ts = Timestamp.valueOf(time);
        Calendar calendar = getCalendar();
        calendar.setTime(ts);
        JDateTime jDateTime = new JDateTime(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH) + 1, calendar.get(Calendar.DAY_OF_MONTH));
        int days = jDateTime.getJulianDayNumber();
        long hour = calendar.get(Calendar.HOUR_OF_DAY);
        long minute = calendar.get(Calendar.MINUTE);
        long second = calendar.get(Calendar.SECOND);
        long nanos = ts.getNanos();
        long nanosOfDay = nanos + NANOS_PER_SECOND * second + NANOS_PER_SECOND * SECONDS_PER_MINUTE * minute + NANOS_PER_SECOND * SECONDS_PER_MINUTE
                * MINUTES_PER_HOUR * hour;
        return new NanoTime(days, nanosOfDay);
    }

在上述方法中使用镶木地板书写时-

writer.write(sfg.newGroup().append("stringField", "abc").append("createdAt", getNanoTime("2017-05-23 11:59:43.345717").toBinary()));

使用ParquetWriter

1 个答案: