java.lang.Object
- com.opencsv.CSVReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Iterable<java.lang.String[]>

Direct Known Subclasses:

CSVReaderHeaderAware
```
public class CSVReader
extends java.lang.Object
implements java.io.Closeable, java.lang.Iterable<java.lang.String[]>
```
A very simple CSV reader released under a commercial-friendly license.

Field Summary

Fields
Modifier and Type	Field	Description
`protected java.io.BufferedReader`	`br`
`(package private) static int`	`CONTEXT_MULTILINE_EXCEPTION_MESSAGE_SIZE`
`static boolean`	`DEFAULT_KEEP_CR`
`static int`	`DEFAULT_MULTILINE_LIMIT`	The default limit for the number of lines in a multiline record.
`static int`	`DEFAULT_SKIP_LINES`	The default line to start reading.
`static boolean`	`DEFAULT_VERIFY_READER`
`protected java.util.Locale`	`errorLocale`
`protected boolean`	`hasNext`
`protected boolean`	`keepCR`
`protected LineReader`	`lineReader`
`protected long`	`linesRead`
`protected boolean`	`linesSkipped`
`private LineValidatorAggregator`	`lineValidatorAggregator`
`private static int`	`MAX_WIDTH`
`protected int`	`multilineLimit`
`protected ICSVParser`	`parser`
`protected static java.util.List<java.lang.Class<? extends java.io.IOException>>`	`PASSTHROUGH_EXCEPTIONS`
`protected java.lang.String[]`	`peekedLine`
`protected java.util.Queue<OrderedObject<java.lang.String>>`	`peekedLines`
`static int`	`READ_AHEAD_LIMIT`
`protected long`	`recordsRead`
`private RowProcessor`	`rowProcessor`
`private RowValidatorAggregator`	`rowValidatorAggregator`
`protected int`	`skipLines`
`protected boolean`	`verifyReader`

Constructor Summary

Constructors
Constructor	Description
`CSVReader(java.io.Reader reader)`	Constructs CSVReader using defaults for all parameters.
`CSVReader(java.io.Reader reader, int line, ICSVParser icsvParser, boolean keepCR, boolean verifyReader, int multilineLimit, java.util.Locale errorLocale, LineValidatorAggregator lineValidatorAggregator, RowValidatorAggregator rowValidatorAggregator, RowProcessor rowProcessor)`	Constructs CSVReader with supplied CSVParser.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes the underlying reader.
`protected java.lang.String[]`	`combineResultsFromMultipleReads(java.lang.String[] buffer, java.lang.String[] lastRead)`	For multi-line records this method combines the current result with the result from previous read(s).
`private java.lang.String[]`	`flexibleRead(boolean popLine, boolean validate)`	Reads a line of input, popping or validating as desired.
`long`	`getLinesRead()`	This method returns the number of lines that has been read from the reader passed into the CSVReader.
`int`	`getMultilineLimit()`	Only useful for tests.
`protected java.lang.String`	`getNextLine()`	Reads the next line from the file.
`ICSVParser`	`getParser()`
`long`	`getRecordsRead()`	Used for debugging purposes, this method returns the number of records that has been read from the CSVReader.
`int`	`getSkipLines()`	Returns the number of lines in the CSV file to skip before processing.
`protected boolean`	`isClosed()`	Checks to see if the file is closed.
`java.util.Iterator<java.lang.String[]>`	`iterator()`	Creates an Iterator for processing the CSV data.
`boolean`	`keepCarriageReturns()`	Returns if the reader will keep carriage returns found in data or remove them.
`java.lang.String[]`	`peek()`	Returns the next line from the input without removing it from the CSVReader and not running any validators.
`private void`	`primeNextRecord()`	Reads the next line from the buffer and converts to a string array.
`java.util.List<java.lang.String[]>`	`readAll()`	Reads the entire file into a List with each element being a String[] of tokens.
`java.lang.String[]`	`readNext()`	Reads the next line from the buffer and converts to a string array.
`java.lang.String[]`	`readNextSilently()`	Reads the next line from the buffer and converts to a string array without running the custom defined validators.
`void`	`setErrorLocale(java.util.Locale errorLocale)`	Sets the locale for all error messages.
`void`	`skip(int numberOfLinesToSkip)`	Skip a given number of lines.
`private void`	`validateLine(long lastSuccessfulLineRead, java.lang.String nextLine)`	Runs all line validators on the input.
`protected void`	`validateResult(java.lang.String[] result, long lineStartOfRow)`	Increments the number of records read if the result passed in is not null.
`boolean`	`verifyReader()`	Returns if the CSVReader will verify the reader before each read.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Field Detail
  - DEFAULT_KEEP_CR
```
public static final boolean DEFAULT_KEEP_CR
```
    See Also:
    
    Constant Field Values
  - DEFAULT_VERIFY_READER
```
public static final boolean DEFAULT_VERIFY_READER
```
    See Also:
    
    Constant Field Values
  - CONTEXT_MULTILINE_EXCEPTION_MESSAGE_SIZE
```
static final int CONTEXT_MULTILINE_EXCEPTION_MESSAGE_SIZE
```
    See Also:
    
    Constant Field Values
  - DEFAULT_SKIP_LINES
```
public static final int DEFAULT_SKIP_LINES
```
    The default line to start reading.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_MULTILINE_LIMIT
```
public static final int DEFAULT_MULTILINE_LIMIT
```
    The default limit for the number of lines in a multiline record. Less than one means no limit.
    
    See Also:
    
    Constant Field Values
  - PASSTHROUGH_EXCEPTIONS
```
protected static final java.util.List<java.lang.Class<? extends java.io.IOException>> PASSTHROUGH_EXCEPTIONS
```
  - READ_AHEAD_LIMIT
```
public static final int READ_AHEAD_LIMIT
```
    See Also:
    
    Constant Field Values
  - MAX_WIDTH
```
private static final int MAX_WIDTH
```
    See Also:
    
    Constant Field Values
  - parser
```
protected ICSVParser parser
```
  - skipLines
```
protected int skipLines
```
  - br
```
protected java.io.BufferedReader br
```
  - lineReader
```
protected LineReader lineReader
```
  - hasNext
```
protected boolean hasNext
```
  - linesSkipped
```
protected boolean linesSkipped
```
  - keepCR
```
protected boolean keepCR
```
  - verifyReader
```
protected boolean verifyReader
```
  - multilineLimit
```
protected int multilineLimit
```
  - errorLocale
```
protected java.util.Locale errorLocale
```
  - linesRead
```
protected long linesRead
```
  - recordsRead
```
protected long recordsRead
```
  - peekedLine
```
protected java.lang.String[] peekedLine
```
  - peekedLines
```
protected final java.util.Queue<OrderedObject<java.lang.String>> peekedLines
```
  - lineValidatorAggregator
```
private final LineValidatorAggregator lineValidatorAggregator
```
  - rowValidatorAggregator
```
private final RowValidatorAggregator rowValidatorAggregator
```
  - rowProcessor
```
private final RowProcessor rowProcessor
```
- Constructor Detail
  - CSVReader
```
public CSVReader(java.io.Reader reader)
```
    Constructs CSVReader using defaults for all parameters.
    
    Parameters:
    
    reader - The reader to an underlying CSV source.
  - CSVReader
```
CSVReader(java.io.Reader reader,
          int line,
          ICSVParser icsvParser,
          boolean keepCR,
          boolean verifyReader,
          int multilineLimit,
          java.util.Locale errorLocale,
          LineValidatorAggregator lineValidatorAggregator,
          RowValidatorAggregator rowValidatorAggregator,
          RowProcessor rowProcessor)
```
    Constructs CSVReader with supplied CSVParser.
    This constructor sets all necessary parameters for CSVReader, and intentionally has package access so only the builder can use it.
    
    Parameters:
    
    reader - The reader to an underlying CSV source
    
    line - The number of lines to skip before reading
    
    icsvParser - The parser to use to parse input
    
    keepCR - True to keep carriage returns in data read, false otherwise
    
    verifyReader - True to verify reader before each read, false otherwise
    
    multilineLimit - Allow the user to define the limit to the number of lines in a multiline record. Less than one means no limit.
    
    errorLocale - Set the locale for error messages. If null, the default locale is used.
    
    lineValidatorAggregator - contains all the custom defined line validators.
    
    rowValidatorAggregator - contains all the custom defined row validators.
    
    rowProcessor - Custom row processor to run on all columns on a csv record.
- Method Detail
  - getParser
```
public ICSVParser getParser()
```
    Returns:
    
    The CSVParser used by the reader.
  - getSkipLines
```
public int getSkipLines()
```
    Returns the number of lines in the CSV file to skip before processing. This is useful when there are miscellaneous data at the beginning of a file.
    
    Returns:
    
    The number of lines in the CSV file to skip before processing.
  - keepCarriageReturns
```
public boolean keepCarriageReturns()
```
    Returns if the reader will keep carriage returns found in data or remove them.
    
    Returns:
    
    True if reader will keep carriage returns, false otherwise.
  - readAll
```
public java.util.List<java.lang.String[]> readAll()
                                           throws java.io.IOException,
                                                  CsvException
```
    Reads the entire file into a List with each element being a String[] of tokens. Since the current implementation returns a LinkedList, you are strongly discouraged from using index-based access methods to get at items in the list. Instead, iterate over the list.
    
    Returns:
    
    A List of String[], with each String[] representing a line of the file.
    
    Throws:
    
    java.io.IOException - If bad things happen during the read
    
    CsvException - If there is a failed validator
  - readNext
```
public java.lang.String[] readNext()
                            throws java.io.IOException,
                                   CsvValidationException
```
    Reads the next line from the buffer and converts to a string array.
    
    Returns:
    
    A string array with each comma-separated element as a separate entry, or null if there is no more input.
    
    Throws:
    
    java.io.IOException - If bad things happen during the read
    
    CsvValidationException - If a user-defined validator fails
  - readNextSilently
```
public java.lang.String[] readNextSilently()
                                    throws java.io.IOException
```
    Reads the next line from the buffer and converts to a string array without running the custom defined validators. This is called by the bean readers when reading the header.
    
    Returns:
    
    A string array with each comma-separated element as a separate entry, or null if there is no more input.
    
    Throws:
    
    java.io.IOException - If bad things happen during the read.
  - primeNextRecord
```
private void primeNextRecord()
                      throws java.io.IOException
```
    Reads the next line from the buffer and converts to a string array. The results are stored in peekedLines and peekedLine.
    
    Throws:
    
    java.io.IOException - If bad things happen during the read
  - validateLine
```
private void validateLine(long lastSuccessfulLineRead,
                          java.lang.String nextLine)
                   throws CsvValidationException
```
    Runs all line validators on the input.
    
    Parameters:
    
    lastSuccessfulLineRead - The line number for error messages
    
    nextLine - The input to be validated
    
    Throws:
    
    CsvValidationException - Only thrown if a user-supplied validator throws it
  - validateResult
```
protected void validateResult(java.lang.String[] result,
                              long lineStartOfRow)
                       throws CsvValidationException
```
    Increments the number of records read if the result passed in is not null.
    
    Parameters:
    
    result - The result of the read operation
    
    lineStartOfRow - Line number that the row started on
    
    Throws:
    
    CsvValidationException - if there is a validation error caught by a custom RowValidator.
  - combineResultsFromMultipleReads
```
protected java.lang.String[] combineResultsFromMultipleReads(java.lang.String[] buffer,
                                                             java.lang.String[] lastRead)
```
    For multi-line records this method combines the current result with the result from previous read(s).
    
    Parameters:
    
    buffer - Previous data read for this record
    
    lastRead - Latest data read for this record.
    
    Returns:
    
    String array with union of the buffer and lastRead arrays.
  - getNextLine
```
protected java.lang.String getNextLine()
                                throws java.io.IOException
```
    Reads the next line from the file.
    
    Returns:
    
    The next line from the file without trailing newline, or null if there is no more input.
    
    Throws:
    
    java.io.IOException - If bad things happen during the read
  - getMultilineLimit
```
public int getMultilineLimit()
```
    Only useful for tests.
    
    Returns:
    
    The maximum number of lines allowed in a multiline record.
  - isClosed
```
protected boolean isClosed()
                    throws java.io.IOException
```
    Checks to see if the file is closed.
    Certain IOExceptions will be passed out, as they are indicative of a real problem, not that the file has already been closed. These exceptions are:
    
    CharacterCodingException
    
    CharConversionException
    
    FileNotFoundException
    
    UnsupportedEncodingException
    
    UTFDataFormatException
    
    ZipException
    
    MalformedInputException
    Returns:
    
    true if the reader can no longer be read from
    
    Throws:
    
    java.io.IOException - If verifyReader() was set to true certain IOExceptions will still be passed out as they are indicative of a problem, not end of file.
  - close
```
public void close()
           throws java.io.IOException
```
    Closes the underlying reader.
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Specified by:
    
    close in interface java.io.Closeable
    
    Throws:
    
    java.io.IOException - If the close fails
  - iterator
```
public java.util.Iterator<java.lang.String[]> iterator()
```
    Creates an Iterator for processing the CSV data.
    
    Specified by:
    
    iterator in interface java.lang.Iterable<java.lang.String[]>
    
    Returns:
    
    A String[] iterator.
  - verifyReader
```
public boolean verifyReader()
```
    Returns if the CSVReader will verify the reader before each read.
    By default the value is true, which is the functionality for version 3.0. If set to false the reader is always assumed ready to read - this is the functionality for version 2.4 and before.
    
    The reason this method was needed was that certain types of readers would return false for their ready() methods until a read was done (namely readers created using Channels). This caused opencsv not to read from those readers.
    
    Returns:
    
    True if CSVReader will verify the reader before reads. False otherwise.
    
    Since:
    
    3.3
    
    See Also:
    
    Bug 108
  - getLinesRead
```
public long getLinesRead()
```
    This method returns the number of lines that has been read from the reader passed into the CSVReader.
    Given the following data:
    
    First line in the file some other descriptive line a,b,c a,"b\nb",c
    
    With a CSVReader constructed like so:
    CSVReader c = builder.withCSVParser(new CSVParser()) .withSkipLines(2) .build();
    The initial call to getLinesRead() will be 0. After the first call to readNext() then getLinesRead() will return 3 (because the header was read). After the second call to read the blank line then getLinesRead() will return 4 (still a read). After the third call to readNext(), getLinesRead() will return 6 because it took two line reads to retrieve this record. Subsequent calls to readNext() (since we are out of data) will not increment the number of lines read.
    Returns:
    
    The number of lines read by the reader (including skipped lines).
    
    Since:
    
    3.6
  - getRecordsRead
```
public long getRecordsRead()
```
    Used for debugging purposes, this method returns the number of records that has been read from the CSVReader.
    Given the following data:
    
    First line in the file some other descriptive line a,b,c a,"b\nb",c
    With a CSVReader constructed like so:
    CSVReader c = builder.withCSVParser(new CSVParser()) .withSkipLines(2) .build();
    The initial call to getRecordsRead() will be 0. After the first call to readNext() then getRecordsRead() will return 1. After the second call to read the blank line then getRecordsRead() will return 2 (a blank line is considered a record with one empty field). After third call to readNext() getRecordsRead() will return 3 because even though it reads to retrieve this record, it is still a single record read. Subsequent calls to readNext() (since we are out of data) will not increment the number of records read.
    
    An example of this is in the linesAndRecordsRead() test in CSVReaderTest.
    Returns:
    
    The number of records (array of Strings[]) read by the reader.
    
    Since:
    
    3.6
    
    See Also:
    
    Feature Request 73
  - skip
```
public void skip(int numberOfLinesToSkip)
          throws java.io.IOException
```
    Skip a given number of lines.
    
    Parameters:
    
    numberOfLinesToSkip - The number of lines to skip
    
    Throws:
    
    java.io.IOException - If anything bad happens when reading the file
    
    Since:
    
    4.2
  - setErrorLocale
```
public void setErrorLocale(java.util.Locale errorLocale)
```
    Sets the locale for all error messages.
    
    Parameters:
    
    errorLocale - Locale for error messages. If null, the default locale is used.
    
    Since:
    
    4.2
  - peek
```
public java.lang.String[] peek()
                        throws java.io.IOException
```
    Returns the next line from the input without removing it from the CSVReader and not running any validators. Subsequent calls to this method will continue to return the same line until a call is made to readNext() or any other method that advances the cursor position in the input. The first call to readNext() after calling this method will return the same line this method does.
    
    Returns:
    
    The next line from the input, or null if there are no more lines
    
    Throws:
    
    java.io.IOException - If bad things happen during the read operation
    
    Since:
    
    4.2
  - flexibleRead
```
private java.lang.String[] flexibleRead(boolean popLine,
                                        boolean validate)
                                 throws java.io.IOException,
                                        CsvValidationException
```
    Reads a line of input, popping or validating as desired.
    
    Parameters:
    
    popLine - Whether the line returned should be popped off the queue of input. If this is true, this method consumes the line and further calls will return the next line of input. If false, the line returned stays in the queue and further calls to this method will return the same line again.
    
    validate - Whether all user-supplied validators should be run.
    
    Returns:
    
    The next line of input
    
    Throws:
    
    java.io.IOException - If this exception is thrown while reading
    
    CsvValidationException - If a user-supplied validator throws it

Class CSVReader

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Field Detail

DEFAULT_KEEP_CR

DEFAULT_VERIFY_READER

CONTEXT_MULTILINE_EXCEPTION_MESSAGE_SIZE

DEFAULT_SKIP_LINES

DEFAULT_MULTILINE_LIMIT

PASSTHROUGH_EXCEPTIONS

READ_AHEAD_LIMIT

MAX_WIDTH

parser

skipLines

br

lineReader

hasNext

linesSkipped

keepCR

verifyReader

multilineLimit

errorLocale

linesRead

recordsRead

peekedLine

peekedLines

lineValidatorAggregator

rowValidatorAggregator

rowProcessor

Constructor Detail

CSVReader

CSVReader

Method Detail

getParser

getSkipLines

keepCarriageReturns

readAll

readNext

readNextSilently

primeNextRecord

validateLine

validateResult

combineResultsFromMultipleReads

getNextLine

getMultilineLimit

isClosed

close

iterator

verifyReader

getLinesRead

getRecordsRead

skip

setErrorLocale

peek

flexibleRead