Java SequenceWriter类代码示例

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
static void dumpTable(String tableName, Writer output, Connection conn) throws IOException, SQLException {
	final String sql = "SELECT * FROM \"" + tableName + "\"";
	try (final Statement dumpStatement = conn.createStatement();
			final ResultSet results = dumpStatement.executeQuery(sql);) {
		final ResultSetMetaData metadata = results.getMetaData();
		final int columnCount = metadata.getColumnCount();
		final List<String> columnNames = new ArrayList<>(columnCount);
		for (int i = 1; i <= columnCount; i++) {
			columnNames.add(metadata.getColumnLabel(i));
		}
		final Writer writer = output;
		final SequenceWriter csvWriter = CSVStream.newCSVWriter(writer, columnNames);
		final List<String> nextResult = new ArrayList<>(columnCount);
		while (results.next()) {
			for (int i = 1; i <= columnCount; i++) {
				nextResult.add(i - 1, results.getString(i));
			}
			csvWriter.write(nextResult);
			nextResult.clear();
		}
	}
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
@Test
public final void testWriteFullCode()
	throws Exception
{
	List<String> headers = Arrays.asList("TestHeader1", "TestHeader2");
	List<List<String>> dataSource = Arrays.asList();
	// Or alternatively,
	// List<List<String>> dataSource = Arrays.asList(Arrays.asList("TestValue1", "TestValue2"));
	java.io.Writer writer = new StringWriter();
	CsvSchema.Builder builder = CsvSchema.builder();
	for (String nextHeader : headers) {
		builder = builder.addColumn(nextHeader);
	}
	CsvSchema schema = builder.setUseHeader(true).build();
	try (SequenceWriter csvWriter = new CsvMapper().writerWithDefaultPrettyPrinter().with(schema).forType(
			List.class).writeValues(writer);)
	{
		for (List<String> nextRow : dataSource) {
			csvWriter.write(nextRow);
		}
		// Check to see whether dataSource is empty 
		// and if so write a single empty list to trigger header output
		if (dataSource.isEmpty()) {
			csvWriter.write(Arrays.asList());
		}
	}
	System.out.println(writer.toString());
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
private static void runMapper(Reader input, List<ValueMapping> map, Writer output, boolean writeHeaders,
		List<String> outputHeaders, List<String> overrideHeaders, int headerLineCount, CsvMapper inputMapper,
		CsvSchema inputSchema) throws ScriptException, IOException {

	final Map<String, String> defaultValues = ValueMapping.getDefaultValuesFromList(map);
	final CsvSchema schema = CSVStream.buildSchema(outputHeaders, writeHeaders);
	final Writer writer = output;

	try (final SequenceWriter csvWriter = CSVStream.newCSVWriter(writer, schema);) {
		final List<String> inputHeaders = new ArrayList<>();
		final List<String> previousLine = new ArrayList<>();
		final List<String> previousMappedLine = new ArrayList<>();
		final JDefaultDict<String, Set<String>> primaryKeys = new JDefaultDict<>(k -> new HashSet<>());
		final JDefaultDict<String, JDefaultDict<String, AtomicInteger>> valueCounts = new JDefaultDict<>(
				k -> new JDefaultDict<>(v -> new AtomicInteger(0)));
		final AtomicInteger lineNumber = new AtomicInteger(0);
		final AtomicInteger filteredLineNumber = new AtomicInteger(0);
		final long startTime = System.currentTimeMillis();
		final BiConsumer<List<String>, List<String>> mapLineConsumer = Unchecked.biConsumer((l, m) -> {
			previousLine.clear();
			previousLine.addAll(l);
			previousMappedLine.clear();
			previousMappedLine.addAll(m);
			csvWriter.write(m);
		});
		CSVStream.parse(input, h -> inputHeaders.addAll(h), (h, l) -> {
			final int nextLineNumber = lineNumber.incrementAndGet();
			if (nextLineNumber % 1000 == 0) {
				double secondsSinceStart = (System.currentTimeMillis() - startTime) / 1000.0d;
				System.out.printf("%d\tSeconds since start: %f\tRecords per second: %f%n", nextLineNumber,
						secondsSinceStart, nextLineNumber / secondsSinceStart);
			}
			final int nextFilteredLineNumber = filteredLineNumber.incrementAndGet();
			try {
				List<String> mapLine = ValueMapping.mapLine(new ValueMappingContext(inputHeaders, l, previousLine,
						previousMappedLine, map, primaryKeys, valueCounts, nextLineNumber, nextFilteredLineNumber,
						mapLineConsumer, outputHeaders, defaultValues, Optional.empty()));
				mapLineConsumer.accept(l, mapLine);
			} catch (final LineFilteredException e) {
				// Swallow line filtered exception and return null below to
				// eliminate it
				// We expect streamCSV to operate in sequential order, print
				// a warning if it doesn't
				boolean success = filteredLineNumber.compareAndSet(nextFilteredLineNumber,
						nextFilteredLineNumber - 1);
				if (!success) {
					System.out.println("Line numbers may not be consistent");
				}
			}
			return null;
		}, l -> {
		}, overrideHeaders, Collections.emptyList(), headerLineCount, inputMapper, inputSchema);
	}
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
private static void debugTable(Table table, SequenceWriter columnCsv) throws IOException {

		System.out.println("\tTable columns for " + table.getName());

		try {
			for (Column nextColumn : table.getColumns()) {
				System.out.println("\t\t" + nextColumn.getName());
				columnCsv.write(Arrays.asList(table.getName() + "." + nextColumn.getName(),
						table.getName() + "." + nextColumn.getName(), "", ""));
			}

			Index primaryKeyIndex = table.getPrimaryKeyIndex();
			System.out.println(
					"\tFound primary key index for table: " + table.getName() + " named " + primaryKeyIndex.getName());
			debugIndex(primaryKeyIndex, new HashSet<>(), columnCsv);

			for (Index nextIndex : table.getIndexes()) {
				if (!nextIndex.getName().equals(primaryKeyIndex.getName())) {
					System.out.println("\tFound non-primary key index for table: " + table.getName() + " named "
							+ nextIndex.getName());
					debugIndex(nextIndex, new HashSet<>(), null);
				}
			}
		} catch (IllegalArgumentException e) {
			System.out.println("No primary key index found for table: " + table.getName());
		}

		Cursor cursor = table.getDefaultCursor();
		int i = 0;
		while (cursor.moveToNextRow()) {
			if (i >= 5) {
				break;
			}
			System.out.println(cursor.getCurrentRow().toString());
			i++;
		}
	}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
private static void debugIndex(Index index, Set<Index> visited, SequenceWriter csvWriter) throws IOException {
	visited.add(index);
	System.out.println("\t\tIndex columns:");
	StringBuilder columnList = new StringBuilder();
	for (Index.Column nextColumn : index.getColumns()) {
		System.out.print("\t\t\t" + nextColumn.getName());

		if (columnList.length() > 0) {
			columnList.append(",");
		}
		columnList.append(index.getTable().getName() + "." + nextColumn.getName());
	}
	if (csvWriter != null) {
		csvWriter.write(
				Arrays.asList(columnList.toString(), columnList.toString(), "Access", columnList.toString()));
	}

	System.out.println("");
	Index referencedIndex = index.getReferencedIndex();
	if (referencedIndex != null) {
		System.out.println("\t" + index.getName() + " references another index: " + referencedIndex.getName());
		if (!visited.contains(referencedIndex)) {
			visited.add(referencedIndex);
			debugIndex(referencedIndex, visited, null);
		}

	}

}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
static <T> void write(Class<T> type, Iterable<? extends T> elements, OutputStream output) throws IOException {
    ObjectMapper mapper = new ObjectMapper()
            .setSerializationInclusion(JsonInclude.Include.NON_ABSENT);
    try (SequenceWriter writer = mapper.writerFor(type).writeValues(output).init(false)) {
        writer.writeAll(elements);
    }
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
private void writeJsonFS(OutputStream output) throws IOException {
    SequenceWriter seqWriter = writer.writeValues(output);
    boolean first = true;
    output.write((byte)'[');
    for (FileDescriptor desc : rootFileDescriptor.getChildFiles()) {
        if (!first) {
            output.write((byte)',');
        }
        first = false;
        seqWriter.write(desc);
    }
    output.write((byte)']');
    seqWriter.flush();
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
public static String createCSV(final CsvMapper csvMapper,
        final RaceResult raceResult) throws IOException {
    CsvSchema schema =
            CsvSchema.builder().addColumns(getColumns(raceResult)).build().withHeader();

    List<Map<String, Object>> rows = new ArrayList<>();

    List<Starter> starters = raceResult.getStarters();
    if (starters != null && !starters.isEmpty()) {
        for (Starter starter : starters) {
            Map<String, Object> row = new LinkedHashMap<>();
            row.put("date", raceResult.getRaceDate().toString());
            row.put("track", raceResult.getTrack().getCode());
            row.put("raceNumber", raceResult.getRaceNumber());
            row.put("name", starter.getHorse().getName());
            row.put("pp", starter.getPostPosition());
            row.put("weight", starter.getWeight().getWeightCarried());
            row.put("odds", TWO_DECIMALS.format(starter.getOdds()));
            row.put("position", starter.getOfficialPosition());

            List<FractionalPoint.Split> splits = starter.getSplits();
            for (int i = 0; i < splits.size(); i++) {
                FractionalPoint.Split split = splits.get(i);
                if (split.hasFractionalValue()) {
                    row.put(split.getText(),
                            THREE_DECIMALS.format(split.getMillis() / (double) 1000));
                }
            }

            rows.add(row);
        }
    }

    try (StringWriter stringWriter = new StringWriter()) {
        try (SequenceWriter sequenceWriter =
                     csvMapper.writer(schema).writeValues(stringWriter).writeAll(rows)) {
            sequenceWriter.flush();
        }
        return stringWriter.toString();
    }
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
public static String createCSV(final CsvMapper csvMapper,
        final List<RaceResult> raceResults) throws IOException {
    if (raceResults != null && !raceResults.isEmpty()) {
        RaceResult result = raceResults.get(0);
        CsvSchema schema =
                CsvSchema.builder().addColumns(getColumns(result)).build().withHeader();

        List<Map<String, Object>> rows = new ArrayList<>();

        for (RaceResult raceResult : raceResults) {
            Map<String, Object> row = new LinkedHashMap<>();
            row.put("date", raceResult.getRaceDate().toString());
            row.put("track", raceResult.getTrack().getCode());
            row.put("raceNumber", raceResult.getRaceNumber());

            RaceTypeNameBlackTypeBreed typeBreedName =
                    raceResult.getRaceConditions().getRaceTypeNameBlackTypeBreed();
            row.put("breed", typeBreedName.getBreed());
            row.put("type", typeBreedName.getType());
            row.put("name", typeBreedName.getName());

            row.put("distance", TWO_DECIMALS.format((double) raceResult
                    .getDistanceSurfaceTrackRecord().getRaceDistance().getFeet() / 660));
            row.put("surface", raceResult.getDistanceSurfaceTrackRecord().getSurface());
            row.put("trackCondition",
                    raceResult.getDistanceSurfaceTrackRecord().getTrackCondition());
            row.put("runners", raceResult.getNumberOfRunners());

            Starter winner = raceResult.getWinners().get(0);
            row.put("winner", winner.getHorse().getName());
            row.put("pp", winner.getPostPosition());
            row.put("jockey", winner.getJockey().getName());
            row.put("trainer", winner.getTrainer().getName());
            row.put("odds", TWO_DECIMALS.format(winner.getOdds()));

            row.put("time", raceResult.getWinningTime());

            rows.add(row);
        }

        try (StringWriter stringWriter = new StringWriter()) {
            try (SequenceWriter sequenceWriter =
                         csvMapper.writer(schema).writeValues(stringWriter).writeAll(rows)) {
                sequenceWriter.flush();
            }
            return stringWriter.toString();
        }
    }
    return null;
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
public static <I, O> ICloseableConsumer<I, Boolean, IOException> consumer(
    final OutputStream outputStream,
    final Class<O> clazz,
    final IProcedure<JsonGenerator, IOException> initializer,
    final IConverter<I, O, IOException> converter,
    final IProcedure<JsonGenerator, IOException> closer) {
  return new ICloseableConsumer<I, Boolean, IOException>() {

    private boolean isClosed = false;
    private JsonGenerator generator;
    private SequenceWriter writer;

    @Override
    public void close() throws IOException {
      check();
      this.isClosed = true;
      IOException exception = JsonObjectUtilities.close(() -> closer.execute(this.generator), null);
      exception = JsonObjectUtilities.close(this.writer, exception);
      exception = JsonObjectUtilities.close(this.generator, exception);
      if (exception != null) {
        throw exception;
      }
    }

    @Override
    public Boolean consume(final I object) throws IOException {
      check();
      if (this.generator == null) {
        initialize();
      }
      final O value = converter.convert(object);
      if (value == null) {
        return false;
      }
      this.writer.write(value);
      return true;
    }

    private void check() throws IOException {
      if (this.isClosed) {
        throw new IOException("consumer is closed"); //$NON-NLS-1$
      }
    }

    private void initialize() throws IOException {
      this.generator = new JsonFactory().createGenerator(outputStream).configure(Feature.AUTO_CLOSE_TARGET, false);
      initializer.execute(this.generator);
      this.writer = new ObjectMapper()
          .writerFor(clazz)
          .with(SerializationFeature.FLUSH_AFTER_WRITE_VALUE)
          .writeValuesAsArray(this.generator);
    }
  };
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
private static void runMapper(Reader input, List<ValueMapping> map, Writer output, JsonPointer basePath,
		ObjectMapper jsonMapper, boolean writeHeaders) throws ScriptException, IOException {

	final List<String> inputHeaders = ValueMapping.getInputFieldsFromList(map);
	final List<String> outputHeaders = ValueMapping.getOutputFieldsFromList(map);
	final Map<String, String> defaultValues = ValueMapping.getDefaultValuesFromList(map);
	final Map<String, Optional<JsonPointer>> fieldRelativePaths = map.stream()
			.collect(Collectors.toMap(ValueMapping::getOutputField,
					nextMapping -> nextMapping.getInputField().trim().isEmpty() ? Optional.empty()
							: Optional.of(JsonPointer.compile(nextMapping.getInputField()))));
	final CsvSchema schema = CSVStream.buildSchema(outputHeaders, writeHeaders);
	final Writer writer = output;

	try (final SequenceWriter csvWriter = CSVStream.newCSVWriter(writer, schema);) {
		final List<String> previousLine = new ArrayList<>();
		final List<String> previousMappedLine = new ArrayList<>();
		final JDefaultDict<String, Set<String>> primaryKeys = new JDefaultDict<>(k -> new HashSet<>());
		final JDefaultDict<String, JDefaultDict<String, AtomicInteger>> valueCounts = new JDefaultDict<>(
				k -> new JDefaultDict<>(v -> new AtomicInteger(0)));
		final AtomicInteger lineNumber = new AtomicInteger(0);
		final AtomicInteger filteredLineNumber = new AtomicInteger(0);
		final long startTime = System.currentTimeMillis();
		final BiConsumer<List<String>, List<String>> mapLineConsumer = Unchecked.biConsumer((l, m) -> {
			previousLine.clear();
			previousLine.addAll(l);
			previousMappedLine.clear();
			previousMappedLine.addAll(m);
			csvWriter.write(m);
		});
		JSONStream.parse(input, h -> {
		}, (node, headers, line) -> {
			final int nextLineNumber = lineNumber.incrementAndGet();
			if (nextLineNumber % 1000 == 0) {
				double secondsSinceStart = (System.currentTimeMillis() - startTime) / 1000.0d;
				System.out.printf("%d\tSeconds since start: %f\tRecords per second: %f%n", nextLineNumber,
						secondsSinceStart, nextLineNumber / secondsSinceStart);
			}
			final int nextFilteredLineNumber = filteredLineNumber.incrementAndGet();
			try {
				List<String> mapLine = ValueMapping.mapLine(new ValueMappingContext(inputHeaders, line,
						previousLine, previousMappedLine, map, primaryKeys, valueCounts, nextLineNumber,
						nextFilteredLineNumber, mapLineConsumer, outputHeaders, defaultValues, Optional.of(node)));
				mapLineConsumer.accept(line, mapLine);
			} catch (final LineFilteredException e) {
				// Swallow line filtered exception and return null below to
				// eliminate it
				// We expect streamCSV to operate in sequential order, print
				// a warning if it doesn't
				boolean success = filteredLineNumber.compareAndSet(nextFilteredLineNumber,
						nextFilteredLineNumber - 1);
				if (!success) {
					System.out.println("Line numbers may not be consistent");
				}
			}
			return null;
		}, l -> {
		}, basePath, fieldRelativePaths, defaultValues, jsonMapper);
	}
}
 

import com.fasterxml.jackson.databind.SequenceWriter; //导入依赖的package包/类
private static void dumpToCSVs(InputStream input, Path outputDir, String csvPrefix, boolean debug,
		boolean addTableNamePrefix) throws IOException {
	Path tempFile = Files.createTempFile("Source-accessdb", ".accdb");
	Files.copy(input, tempFile, StandardCopyOption.REPLACE_EXISTING);

	try {
		final CsvSchema schema = CSVStream
				.buildSchema(Arrays.asList("OldField", "NewField", "Language", "Mapping"));
		try (final Database db = DatabaseBuilder.open(tempFile.toFile());
				final Writer columnCsv = Files
						.newBufferedWriter(outputDir.resolve(csvPrefix + "AutoMapping-Columns.csv"));
				final SequenceWriter columnCsvWriter = CSVStream.newCSVWriter(new BufferedWriter(columnCsv),
						schema);) {
			for (String tableName : db.getTableNames()) {
				Table table = db.getTable(tableName);

				if (debug) {
					debugTable(table, columnCsvWriter);
				}

				System.out.println("");
				String csvName = csvPrefix + tableName + ".csv";
				Path csvPath = outputDir.resolve(csvName);
				System.out.println("Converting " + tableName + " to CSV: " + csvPath.toAbsolutePath().toString());

				String[] tempArray = new String[table.getColumnCount()];
				int x = 0;
				for (Column nextColumn : table.getColumns()) {
					if (addTableNamePrefix) {
						tempArray[x++] = tableName + "." + nextColumn.getName();
					} else {
						tempArray[x++] = nextColumn.getName();
					}
				}

				final CsvSchema fullFileSchema = CSVStream.buildSchema(Arrays.asList(tempArray));
				try (final Writer fullFileCsv = Files.newBufferedWriter(csvPath);
						final SequenceWriter fullFileCsvWriter = CSVStream
								.newCSVWriter(new BufferedWriter(fullFileCsv), fullFileSchema);) {
					int rows = 0;
					for (Row nextRow : table) {
						int i = 0;
						for (Object nextValue : nextRow.values()) {
							if (nextValue == null) {
								tempArray[i++] = null;
							} else if (nextValue instanceof Date) {
								tempArray[i++] = CSVUtil.oldDateToISO8601LocalDateTime((Date) nextValue);
							} else {
								tempArray[i++] = nextValue.toString();
							}
						}
						fullFileCsvWriter.write(Arrays.asList(tempArray));
						rows++;
					}
					System.out.println("Converted " + rows + " rows from table " + tableName);
				}
				System.out.println("");
				System.out.println("----------------------------");
			}
		}
	} finally {
		Files.deleteIfExists(tempFile);
	}
}