Class CSVPrinter
- java.lang.Object
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- org.apache.commons.csv.CSVPrinter
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- All Implemented Interfaces:
Closeable
,Flushable
,AutoCloseable
public final class CSVPrinter extends Object implements Flushable, Closeable
Prints values in aCSV format
.Values can be appended to the output by calling the
print(Object)
method. Values are printed according toString.valueOf(Object)
. To complete a record theprintln()
method has to be called. Comments can be appended by callingprintComment(String)
. However a comment will only be written to the output if theCSVFormat
supports comments.The printer also supports appending a complete record at once by calling
printRecord(Object...)
orprintRecord(Iterable)
. FurthermoreprintRecords(Object...)
,printRecords(Iterable)
andprintRecords(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
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Constructor Summary
Constructors Constructor Description CSVPrinter(Appendable appendable, CSVFormat format)
Creates a printer that will print values to the given stream following the CSVFormat.
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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.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 a single record of delimiter separated values followed by the record separator.void
printRecord(Object... values)
Prints the given values a single record of delimiter separated values followed by the record separator.void
printRecords(Iterable<?> values)
Prints all the objects in the given collection 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.
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Constructor Detail
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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.
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Method Detail
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close
public void close() throws IOException
- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Throws:
IOException
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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
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flush
public void flush() throws IOException
Flushes the underlying stream.- Specified by:
flush
in interfaceFlushable
- Throws:
IOException
- If an I/O error occurs
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getOut
public Appendable getOut()
Gets the target Appendable.- Returns:
- the target Appendable.
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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
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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 separator.- Parameters:
comment
- the comment to output- Throws:
IOException
- If an I/O error occurs
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printHeaders
public void printHeaders(ResultSet resultSet) throws IOException, SQLException
Prints headers for a result set based on its metadata.- Parameters:
resultSet
- The result set 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
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println
public void println() throws IOException
Outputs the record separator.- Throws:
IOException
- If an I/O error occurs
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printRecord
public void printRecord(Iterable<?> values) throws 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:
IOException
- If an I/O error occurs
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printRecord
public void printRecord(Object... values) throws 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:
IOException
- If an I/O error occurs
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printRecords
public void printRecords(Iterable<?> values) throws 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 usingprintRecord(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:
IOException
- If an I/O error occurs
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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 contains nested collections/arrays those nested elements will each be printed as records usingprintRecord(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
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printRecords
public void printRecords(ResultSet resultSet) throws SQLException, IOException
Prints all the objects in the given JDBC result set.- Parameters:
resultSet
- result set the values to print.- Throws:
IOException
- If an I/O error occursSQLException
- if a database access error occurs
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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 occursSQLException
- if a database access error occurs- Since:
- 1.9.0
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