Package org.apache.commons.csv

Class CSVPrinter

java.lang.Object

org.apache.commons.csv.CSVPrinter

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public final class CSVPrinter
extends Object
implements Flushable, 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) and printRecords(ResultSet) 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(Appendable appendable, CSVFormat format)	Creates a printer that will print values to the given stream following the CSVFormat.

Method Summary

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.
Appendable	getOut()	Gets the target Appendable.
void	print(Object value)	Prints the string as the next value on the line.
void	printComment(String comment)	Prints a comment on a new line among the delimiter-separated values.
void	printHeaders(ResultSet resultSet)	Prints headers for a result set based on its metadata.
void	println()	Outputs the record separator.
void	printRecord(Iterable<?> values)	Prints the given values as a single record of delimiter-separated values followed by the record separator.
void	printRecord(Object... values)	Prints the given values as a single record of delimiter-separated values followed by the record separator.
void	printRecord(Stream<?> values)	Prints the given values as a single record of delimiter-separated values followed by the record separator.
void	printRecords(Iterable<?> values)	Prints all the objects in the given Iterable handling nested collections/arrays as records.
void	printRecords(Object... values)	Prints all the objects in the given array handling nested collections/arrays as records.
void	printRecords(ResultSet resultSet)	Prints all the objects in the given JDBC result set.
void	printRecords(ResultSet resultSet, boolean printHeader)	Prints all the objects with metadata in the given JDBC result set based on the header boolean.
void	printRecords(Stream<?> values)	Prints all the objects in the given Stream 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 Details

CSVPrinter

public CSVPrinter(Appendable appendable,
 CSVFormat format)
           throws 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:

appendable - stream to which to print. Must not be null.

format - the CSV format. Must not be null.

Throws:

IOException - thrown if the optional header cannot be printed.

IllegalArgumentException - thrown if the parameters of the format are inconsistent or if either out or format are null.

Method Details

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

close

public void close(boolean flush)
           throws IOException

Closes the underlying stream with an optional flush first.

Parameters:

flush - whether to flush before the actual close.

Throws:

IOException - If an I/O error occurs

Since:

1.6

flush

public void flush()
           throws IOException

Flushes the underlying stream.

Specified by:

flush in interface Flushable

Throws:

IOException - If an I/O error occurs

getOut

public Appendable getOut()

Gets the target Appendable.

Returns:

the target Appendable.

print

public void print(Object value)
           throws 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:

IOException - If an I/O error occurs

printComment

public void printComment(String comment)
                  throws 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 separators.

Parameters:

comment - the comment to output

Throws:

IOException - If an I/O error occurs

printHeaders

public void printHeaders(ResultSet resultSet)
                  throws IOException,
SQLException

Prints headers for a result set based on its metadata.

Parameters:

resultSet - The ResultSet to query for metadata.

Throws:

IOException - If an I/O error occurs.

SQLException - If a database access error occurs or this method is called on a closed result set.

Since:

1.9.0

println

public void println()
             throws IOException

Outputs the record separator.

Throws:

IOException - If an I/O error occurs

printRecord

public void printRecord(Iterable<?> values)
                 throws IOException

Prints the given values as 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:

IOException - If an I/O error occurs

printRecord

public void printRecord(Object... values)
                 throws IOException

Prints the given values as 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:

IOException - If an I/O error occurs

printRecord

public void printRecord(Stream<?> values)
                 throws IOException

Prints the given values as 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:

IOException - If an I/O error occurs

Since:

1.10.0

printRecords

public void printRecords(Iterable<?> values)
                  throws IOException

Prints all the objects in the given Iterable handling nested collections/arrays as records.

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

Given the following data structure:

 
 List<String[]> data = new ArrayList<>();
 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:

IOException - If an I/O error occurs

printRecords

public void printRecords(Object... values)
                  throws 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 contain nested collections or 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:

IOException - If an I/O error occurs

printRecords

public void printRecords(ResultSet resultSet)
                  throws SQLException,
IOException

Prints all the objects in the given JDBC result set.

Parameters:

resultSet - The values to print.

Throws:

IOException - If an I/O error occurs.

SQLException - Thrown when a database access error occurs.

printRecords

public void printRecords(ResultSet resultSet,
 boolean printHeader)
                  throws SQLException,
IOException

Prints all the objects with metadata in the given JDBC result set based on the header boolean.

Parameters:

resultSet - source of row data.

printHeader - whether to print headers.

Throws:

IOException - If an I/O error occurs

SQLException - if a database access error occurs

Since:

1.9.0

printRecords

public void printRecords(Stream<?> values)
                  throws IOException

Prints all the objects in the given Stream handling nested collections/arrays as records.

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

Given the following data structure:

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

Calling this method will print:

 
 A, B, C
 1, 2, 3
 A1, B2, C3
 
 

Parameters:

values - the values to print.

Throws:

IOException - If an I/O error occurs

Since:

1.10.0