Module org.apache.commons.csv
Package org.apache.commons.csv

Class CSVPrinter

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable
    public final class CSVPrinter
extends java.lang.Object
implements java.io.Flushable, java.io.Closeable
    Prints values in a CSV format.

    Values can be appended to the output by calling the print(Object) method. Values are printed according to String.valueOf(Object). To complete a record the println() method has to be called. Comments can be appended by calling printComment(String). However a comment will only be written to the output if the CSVFormat supports comments.

    The printer also supports appending a complete record at once by calling printRecord(Object...) or printRecord(Iterable). Furthermore printRecords(Object...), printRecords(Iterable) methods can be used to print several records at once.

    Example:

     try (CSVPrinter printer = new CSVPrinter(new FileWriter("csv.txt"), CSVFormat.EXCEL)) {
     printer.printRecord("id", "userName", "firstName", "lastName", "birthday");
     printer.printRecord(1, "john73", "John", "Doe", LocalDate.of(1973, 9, 15));
     printer.println();
     printer.printRecord(2, "mary", "Mary", "Meyer", LocalDate.of(1985, 3, 29));
 } catch (IOException ex) {
     ex.printStackTrace();
 }

    This code will write the following to csv.txt:

     id,userName,firstName,lastName,birthday
 1,john73,John,Doe,1973-09-15

 2,mary,Mary,Meyer,1985-03-29

    • Constructor Summary

      Constructors 
      Constructor Description
      CSVPrinter​(java.lang.Appendable out, CSVFormat format)
      Creates a printer that will print values to the given stream following the CSVFormat.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()  
      void close​(boolean flush)
      Closes the underlying stream with an optional flush first.
      void flush()
      Flushes the underlying stream.
      java.lang.Appendable getOut()
      Gets the target Appendable.
      void print​(java.lang.Object value)
      Prints the string as the next value on the line.
      void printComment​(java.lang.String comment)
      Prints a comment on a new line among the delimiter separated values.
      void println()
      Outputs the record separator.
      void printRecord​(java.lang.Iterable<?> values)
      Prints the given values a single record of delimiter separated values followed by the record separator.
      void printRecord​(java.lang.Object... values)
      Prints the given values a single record of delimiter separated values followed by the record separator.
      void printRecords​(java.lang.Iterable<?> values)
      Prints all the objects in the given collection handling nested collections/arrays as records.
      void printRecords​(java.lang.Object... values)
      Prints all the objects in the given array handling nested collections/arrays as records.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • CSVPrinter

        public CSVPrinter​(java.lang.Appendable out,
                  CSVFormat format)
           throws java.io.IOException
        Creates a printer that will print values to the given stream following the CSVFormat.

        Currently, only a pure encapsulation format or a pure escaping format is supported. Hybrid formats (encapsulation and escaping with a different character) are not supported.

        Parameters:
        out - stream to which to print. Must not be null.
        format - the CSV format. Must not be null.
        Throws:
        java.io.IOException - thrown if the optional header cannot be printed.
        java.lang.IllegalArgumentException - thrown if the parameters of the format are inconsistent or if either out or format are null.

    • Method Detail

      • close

        public void close()
           throws java.io.IOException
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Throws:
        java.io.IOException

      • close

        public void close​(boolean flush)
           throws java.io.IOException
        Closes the underlying stream with an optional flush first.
        Parameters:
        flush - whether to flush before the actual close.
        Throws:
        java.io.IOException - If an I/O error occurs
        Since:
        1.6

      • flush

        public void flush()
           throws java.io.IOException
        Flushes the underlying stream.
        Specified by:
        flush in interface java.io.Flushable
        Throws:
        java.io.IOException - If an I/O error occurs

      • getOut

        public java.lang.Appendable getOut()
        Gets the target Appendable.
        Returns:
        the target Appendable.

      • print

        public void print​(java.lang.Object value)
           throws java.io.IOException
        Prints the string as the next value on the line. The value will be escaped or encapsulated as needed.
        Parameters:
        value - value to be output.
        Throws:
        java.io.IOException - If an I/O error occurs

      • printComment

        public void printComment​(java.lang.String comment)
                  throws java.io.IOException
        Prints a comment on a new line among the delimiter separated values.

        Comments will always begin on a new line and occupy at least one full line. The character specified to start comments and a space will be inserted at the beginning of each new line in the comment.

        If comments are disabled in the current CSV format this method does nothing.

        This method detects line breaks inside the comment string and inserts CSVFormat.getRecordSeparator() to start a new line of the comment. Note that this might produce unexpected results for formats that do not use line breaks as record separator.

        Parameters:
        comment - the comment to output
        Throws:
        java.io.IOException - If an I/O error occurs

      • println

        public void println()
             throws java.io.IOException
        Outputs the record separator.
        Throws:
        java.io.IOException - If an I/O error occurs

      • printRecord

        public void printRecord​(java.lang.Iterable<?> values)
                 throws java.io.IOException
        Prints the given values a single record of delimiter separated values followed by the record separator.

        The values will be quoted if needed. Quotes and newLine characters will be escaped. This method adds the record separator to the output after printing the record, so there is no need to call println().

        Parameters:
        values - values to output.
        Throws:
        java.io.IOException - If an I/O error occurs

      • printRecord

        public void printRecord​(java.lang.Object... values)
                 throws java.io.IOException
        Prints the given values a single record of delimiter separated values followed by the record separator.

        The values will be quoted if needed. Quotes and newLine characters will be escaped. This method adds the record separator to the output after printing the record, so there is no need to call println().

        Parameters:
        values - values to output.
        Throws:
        java.io.IOException - If an I/O error occurs

      • printRecords

        public void printRecords​(java.lang.Iterable<?> values)
                  throws java.io.IOException
        Prints all the objects in the given collection handling nested collections/arrays as records.

        If the given collection only contains simple objects, this method will print a single record like printRecord(Iterable). If the given collections contains nested collections/arrays those nested elements will each be printed as records using printRecord(Object...).

        Given the following data structure: 

         
 List<String[]> data = ...
 data.add(new String[]{ "A", "B", "C" });
 data.add(new String[]{ "1", "2", "3" });
 data.add(new String[]{ "A1", "B2", "C3" });

        Calling this method will print: 

         
 A, B, C
 1, 2, 3
 A1, B2, C3
        Parameters:
        values - the values to print.
        Throws:
        java.io.IOException - If an I/O error occurs

      • printRecords

        public void printRecords​(java.lang.Object... values)
                  throws java.io.IOException
        Prints all the objects in the given array handling nested collections/arrays as records.

        If the given array only contains simple objects, this method will print a single record like printRecord(Object...). If the given collections contains nested collections/arrays those nested elements will each be printed as records using printRecord(Object...).

        Given the following data structure: 

         
 String[][] data = new String[3][]
 data[0] = String[]{ "A", "B", "C" };
 data[1] = new String[]{ "1", "2", "3" };
 data[2] = new String[]{ "A1", "B2", "C3" };

        Calling this method will print: 

         
 A, B, C
 1, 2, 3
 A1, B2, C3
        Parameters:
        values - the values to print.
        Throws:
        java.io.IOException - If an I/O error occurs