Java CSVReader类代码示例

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
/**
 * Constructor
 * 
 * @param catalog_tbl
 * @param table_file
 * @param has_header
 *            whether we expect the data file to include a header in the
 *            first row
 * @param auto_generate_first_column
 *            TODO
 * @throws Exception
 */
public TableDataIterable(Table catalog_tbl, File table_file, boolean has_header, boolean auto_generate_first_column) throws Exception {
    this.catalog_tbl = catalog_tbl;
    this.table_file = table_file;
    this.auto_generate_first_column = auto_generate_first_column;
    this.reader = new CSVReader(FileUtil.getReader(this.table_file));

    // Throw away the first row if there is a header
    if (has_header) {
        this.reader.readNext();
        this.line_ctr++;
    }

    // Column Types + Foreign Keys
    // Determine whether the column references a foreign key, and thus will
    // need to be converted to an integer field later
    this.types = new VoltType[catalog_tbl.getColumns().size()];
    this.fkeys = new boolean[this.types.length];
    this.nullable = new boolean[this.types.length];
    for (Column catalog_col : catalog_tbl.getColumns()) {
        int idx = catalog_col.getIndex();
        this.types[idx] = VoltType.get((byte) catalog_col.getType());
        this.fkeys[idx] = (CatalogUtil.getForeignKeyParent(catalog_col) != null);
        this.nullable[idx] = catalog_col.getNullable();
    } // FOR
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
public TestFileIterator(String relationName, Reader reader, char separator, char quotechar,
                    char escape,
                    int skipLines, boolean strictQuotes, boolean ignoreLeadingWhiteSpace,
                    boolean hasHeader, boolean skipDifferingLines)
    throws InputIterationException {
  this.relationName = relationName;
  this.csvReader =
      new CSVReader(reader, separator, quotechar, escape, skipLines, strictQuotes,
                    ignoreLeadingWhiteSpace);
  this.skipDifferingLines = skipDifferingLines;

  this.nextLine = readNextLine();
  if (this.nextLine != null) {
    this.numberOfColumns = this.nextLine.size();
  }

  if (hasHeader) {
    this.headerLine = this.nextLine;
    next();
  }

  // If the header is still null generate a standard header the size of number of columns.
  if (this.headerLine == null) {
    this.headerLine = generateHeaderLine();
  }
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
public static void main(String[] args) throws IOException {
    String pathToFile;
    if (args.length >= 1) {
        pathToFile = args[0];
    } else {
        pathToFile = "emails.csv";
    }

    System.out.println("Reading emails from: " + pathToFile);

    CSVReader reader = new CSVReader(new FileReader(pathToFile));
    List<String> emails = reader.readAll().stream().map(line -> line[0].trim()).collect(Collectors.toList());

    System.out.println("Emails count: " + emails.size());

    String seedString = "";

    List<String> winners = new LotteryMachine(emails, MAX_WINNERS_COUNT).setSeed(seedString).draw();

    System.out.println("Winners:");
    winners.forEach(System.out::println);
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
/**
 * Constructor
 * @param table_file
 * @param has_header whether we expect the data file to include a header in the first row
 * @param auto_generate_first_column TODO
 * @throws Exception
 */
public TableDataIterable(Table catalog_tbl, File table_file, boolean has_header, boolean auto_generate_first_column) throws Exception {
    this.catalog_tbl = catalog_tbl;
    this.table_file = table_file;
    this.auto_generate_first_column = auto_generate_first_column;
    
    this.types = new int[this.catalog_tbl.getColumnCount()];
    this.fkeys = new boolean[this.catalog_tbl.getColumnCount()];
    this.nullable = new boolean[this.catalog_tbl.getColumnCount()];
    for (int i = 0; i < this.types.length; i++) {
        Column catalog_col = this.catalog_tbl.getColumn(i);
        this.types[i] = catalog_col.getType();
        this.fkeys[i] = (catalog_col.getForeignKey() != null);
        this.nullable[i] = catalog_col.isNullable();
    } // FOR
    
    this.reader = new CSVReader(FileUtil.getReader(this.table_file));
    
    // Throw away the first row if there is a header
    if (has_header) {
        this.reader.readNext();
        this.line_ctr++;
    }
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
/**
 * Read all lines. Add positive and negative examples.
 *
 * @param reader
 * @throws IOException
 */
private void readAllLines(CSVReader reader) throws IOException {
	String[] values = null;

	while ((values = reader.readNext()) != null) {

		if (values.length == 3) {

			boolean isPositive = Boolean.parseBoolean(values[2]);

			Pair<String, String> example = new Pair<String, String>(
					values[0], values[1]);

			if (isPositive) {
				addPositiveExample(example);
			} else {
				addNegativeExample(example);
			}

		} else {
			System.err.println(String.format("Skipping malformed line: %s",
					StringUtils.join(values,",")));
		}
	}
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
public LinkedHashMap<String, Vector> loadFacesData(String filepath) {
    LinkedHashMap<String, Vector> data = new LinkedHashMap<>();
    try (CSVReader reader = new CSVReader(new FileReader(filepath), ',')) {
        List<String[]> rows = reader.readAll();
        double[][] faces = new double[rows.size()][128];
        for (int i = 0; i < rows.size(); i++) {
            for (int j = 0; j < 128; j++) {
                faces[i][j] = Double.parseDouble(rows.get(i)[j]);
            }
            // we need to convert the format Adrien_Brody_0007.jpg to Adrien_Brody_7
            data.put(rows.get(i)[128].replace(".jpg", "").replaceAll("0+(?!$)", ""), new Vector(faces[i]));
        }
    } catch (IOException ex) {
        ex.printStackTrace();
    }
    return data;
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
private void loadCSV(File fpIn, Map<Integer,Double> mapForB, Map<Integer,Double> mapForD,
		Map<Integer,Double> mapForR ) throws IOException {
	assertTrue(fpIn.exists());
	CSVReader reader = new CSVReader(new FileReader(fpIn));
	String[] nextLine;
	while ((nextLine = reader.readNext()) != null) {
		String order = nextLine[1].trim();
		switch (order) {
		case PLACEHOLDER_B : mapForB.put(Integer.parseInt(nextLine[0]), Double.parseDouble(nextLine[2]));
							break;
		case PLACEHOLDER_D : mapForD.put(Integer.parseInt(nextLine[0]), Double.parseDouble(nextLine[2]));
							break;
		case PLACEHOLDER_R : mapForR.put(Integer.parseInt(nextLine[0]), Double.parseDouble(nextLine[2]));
							break;
		}
	}
	assertTrue(mapForB.size() > 0);
	assertEquals(mapForB.size(), mapForD.size());
	assertEquals(mapForD.size(), mapForR.size());
	reader.close();
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
@Test
public void testWrite() throws IOException { 
  String[] row1 = new String[] { "oneone", "onetwo", "onethree" };
  String[] row2 = new String[] { "twoone", "twotwo", "twothree" };

  StringWriter sWriter = new StringWriter();
  CSVWriter writer = new CSVWriter(sWriter, ',', '\'');

  writer.writeNext(row1);
  writer.writeNext(row2);

  String written = sWriter.toString();

  CSVReader reader = new CSVReader(new StringReader(written), ',', '\'');
  List<String[]> rows = reader.readAll();
  assertTrue(Arrays.equals(rows.get(0), row1));
  assertTrue(Arrays.equals(rows.get(1), row2));
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
public void addPartialTimesFromFile(Path inputFilePath, FileSystem fileSystem) throws IOException {
    // Creates the reader.
    FSDataInputStream fileInputStream = fileSystem.open(inputFilePath);
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(fileInputStream));
    CSVReader fileReader = new CSVReader(bufferedReader);

    // Iterates among the lines.
    List<String[]> lines = fileReader.readAll();
    for (String[] line : lines) {
        // Reads data.
        int islandNumber = Integer.parseInt(line[ISLAND_NUMBER_PARTIAL_TIMES_HEADER_INDEX]);
        long generationsBlockNumber = Long.parseLong(line[GENERATIONS_BLOCK_NUMBER_PARTIAL_TIMES_HEADER_INDEX]);
        PhaseType phaseType = PhaseType.valueOf(line[PHASE_TYPE_PARTIAL_TIMES_HEADER_INDEX]);
        PartialTimeKey.Type partialTimeType = PartialTimeKey.Type.valueOf(line[TYPE_PARTIAL_TIMES_HEADER_INDEX]);
        long time = Long.parseLong(line[TIME_PARTIAL_TIMES_HEADER_INDEX]);

        // Adds the time.
        this.addPartialTime(islandNumber, generationsBlockNumber, phaseType, partialTimeType, time);
    }
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
public static void main(String[] args) throws IOException {
	
	CSVReader reader = new CSVReader(new FileReader(ADDRESS_FILE));
	String [] nextLine;
	while ((nextLine = reader.readNext()) != null) {
		System.out.println("Name: [" + nextLine[0] + "]\nAddress: [" + nextLine[1] + "]\nEmail: [" + nextLine[2] + "]");
	}
	
	// Try writing it back out as CSV to the console
	CSVReader reader2 = new CSVReader(new FileReader(ADDRESS_FILE));
	List allElements = reader2.readAll();
	StringWriter sw = new StringWriter();
	CSVWriter writer = new CSVWriter(sw);
	writer.writeAll(allElements);
	
	System.out.println("\n\nGenerated CSV File:\n\n");
	System.out.println(sw.toString());
	
	
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
@Override
public void reset() throws IOException {
    csvReader = new CSVReader(new FileReader(file));
    
    String[] line;
    while (null != (line = csvReader.readNext())) {
        if (line.length > 0 && ! Check.isEmpty(line[0])) {
            headings = line;
            break;
        }
    }
    
    if (headings == null) {
        throw new IOException("File only has blank lines");
    }
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
public static void extractRandomConfigs(String inputFile, String outputFile, int nConfigs, int nIterations) throws IOException{
	CSVReader lines = new CSVReader(new FileReader(inputFile), ',');
	List<String[]> content = lines.readAll();
	
	for (int i=0; i<nIterations;i++){
		System.out.println(content.isEmpty());
		// Shuffle list
		Collections.shuffle(content);
		int randomNum = ThreadLocalRandom.current().nextInt(1, content.size() - nConfigs);
		// Write lines
		CSVWriter writer = new CSVWriter(new FileWriter(outputFile+(i+1)+".csv", true),';');
		for(int j=randomNum;j<=randomNum+nConfigs-1;j++){
			writer.writeNext(content.get(j));
		}
		writer.close();
	}
	
	lines.close();
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
/**
 * Generate ReportData from an input stream (normally an HTTP steam of report in CSV format),
 * which will be closed after reading.
 * @param stream the input stream (in CSV format)
 * @param clientCustomerId the client customer ID of this report
 * @return the generated ReportData
 */
public ReportData fromStream(InputStream stream, Long clientCustomerId) throws IOException {
  CSVReader csvReader = new CSVReader(new InputStreamReader(stream, Charset.defaultCharset()));
  String[] headerArray = csvReader.readNext();
  List<String[]> rowsArray = csvReader.readAll();
  csvReader.close();

  int rowsCount = rowsArray.size();
  List<List<String>> rows = new ArrayList<List<String>>(rowsCount);
  for (int i = 0; i < rowsCount; ++i) {
    // need to create a new ArrayList object which is extendible.
    List<String> row = new ArrayList<String>(Arrays.asList(rowsArray.get(i)));
    rows.add(row);
  }

  int columns = headerArray.length;
  List<String> columnNames = new ArrayList<String>(columns);
  for (int i = 0; i < columns; i++) {
    String fieldName = fieldsMapping.get(headerArray[i]);
    Preconditions.checkNotNull(fieldName, "Unknown field name: %s.", fieldName);
    columnNames.add(fieldName);
  }

  return new ReportData(clientCustomerId, reportType, columnNames, rows);
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
public String[]  readMetadataFields(CSVReader reader) throws IOException {
	// read first line from the file, with metadata description
	String[] metadataFields = reader.readNext();

	if(metadataFields==null)
		throw new RuntimeException("Empty input file");

       // if there is a mapping for parameters, use it
       boolean hasFile = false;
       for(int i=0; i < metadataFields.length; i++) {
           String value = getParameter(metadataFields[i]);
           if(value != null)
               metadataFields[i]=value;
           logger.debug("Metadata field " + i + ": " + metadataFields[i]);
           if(Parameters.PARAM_FILE.equals(metadataFields[i]))
               hasFile=true;
       }

       if(!hasFile) {
           throw new RuntimeException("The header should contain the 'file' parameter or there should be a mapping for one of headers parameters to 'file'");
       }

	return metadataFields;
}
 

import au.com.bytecode.opencsv.CSVReader; //导入依赖的package包/类
@Test
public final void testProcessLineWrongNumberOfFields() throws Exception {
	setUp();
	CSVReader reader = metadataLoader.createReader();
	String[] metadataFields = metadataLoader.readMetadataFields(reader);

	String[] line = {"a"};
	try {
		metadataLoader.processLine(line, metadataFields);
	} catch (Throwable e) {
		assert(true);
		return;
	}
	assert(false);
	reader.close();
}