CSVReader (opencsv 5.12.0 API)

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com.opencsv

Class CSVReader

java.lang.Object
- com.opencsv.CSVReader

All Implemented Interfaces:

Closeable, AutoCloseable, Iterable<String[]>

Direct Known Subclasses:

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

Author:

Glen Smith

Field Summary

Fields
Modifier and Type	Field and Description
`protected BufferedReader`	`br`
`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 Locale`	`errorLocale`
`protected boolean`	`hasNext`
`protected boolean`	`keepCR`
`protected LineReader`	`lineReader`
`protected long`	`linesRead`
`protected boolean`	`linesSkipped`
`protected int`	`multilineLimit`
`protected ICSVParser`	`parser`
`protected static List<Class<? extends IOException>>`	`PASSTHROUGH_EXCEPTIONS`
`protected String[]`	`peekedLine`
`protected Queue<OrderedObject<String>>`	`peekedLines`
`static int`	`READ_AHEAD_LIMIT`
`protected long`	`recordsRead`
`protected int`	`skipLines`
`protected boolean`	`verifyReader`

Constructor Summary

Constructors
Constructor and Description

CSVReader (Reader reader)
Constructs CSVReader using defaults for all parameters.

Constructors
Constructor and Description
`CSVReader (Reader reader)` Constructs CSVReader using defaults for all parameters.

Method Summary

All Methods
Modifier and Type	Method and Description
`void`	`close ()` Closes the underlying reader.
`protected String[]`	`combineResultsFromMultipleReads (String[] buffer, String[] lastRead)` For multi-line records this method combines the current result with the result from previous read(s).
`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 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.
`Iterator<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.
`String[]`	`peek ()` Returns the next line from the input without removing it from the CSVReader and not running any validators.
`List<String[]>`	`readAll ()` Reads the entire file into a List with each element being a String[] of tokens.
`String[]`	`readNext ()` Reads the next line from the buffer and converts to a string array.
`String[]`	`readNextSilently ()` Reads the next line from the buffer and converts to a string array without running the custom defined validators.
`void`	`setErrorLocale (Locale errorLocale)` Sets the locale for all error messages.
`void`	`skip (int numberOfLinesToSkip)` Skip a given number of lines.
`protected void`	`validateResult (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
  - 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 List<Class<? extends IOException>> PASSTHROUGH_EXCEPTIONS
```
  - READ_AHEAD_LIMIT
```
public static final int READ_AHEAD_LIMIT
```
    See Also:
    
    Constant Field Values
  - parser
```
protected ICSVParser parser
```
  - skipLines
```
protected int skipLines
```
  - br
```
protected 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 Locale errorLocale
```
  - linesRead
```
protected long linesRead
```
  - recordsRead
```
protected long recordsRead
```
  - peekedLine
```
protected String[] peekedLine
```
  - peekedLines
```
protected final Queue<OrderedObject<String>> peekedLines
```
- Constructor Detail
  - CSVReader
```
public CSVReader(Reader reader)
```
    Constructs CSVReader using defaults for all parameters.
    
    Parameters:
    
    reader - The reader to an underlying CSV source.
- 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 List<String[]> readAll()
 throws 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:
    
    IOException - If bad things happen during the read
    
    CsvException - If there is a failed validator
  - readNext
```
public String[] readNext()
 throws 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:
    
    IOException - If bad things happen during the read
    
    CsvValidationException - If a user-defined validator fails
  - readNextSilently
```
public String[] readNextSilently()
 throws 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:
    
    IOException - If bad things happen during the read.
  - validateResult
```
protected void validateResult(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 String[] combineResultsFromMultipleReads(String[] buffer,
 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 String getNextLine()
 throws 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:
    
    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 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:
    
    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 IOException 
```
    Closes the underlying reader.
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Throws:
    
    IOException - If the close fails
  - iterator
```
public Iterator<String[]> iterator()
```
    Creates an Iterator for processing the CSV data.
    
    Specified by:
    
    iterator in interface Iterable<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 IOException 
```
    Skip a given number of lines.
    
    Parameters:
    
    numberOfLinesToSkip - The number of lines to skip
    
    Throws:
    
    IOException - If anything bad happens when reading the file
    
    Since:
    
    4.2
  - setErrorLocale
```
public void setErrorLocale(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 String[] peek()
 throws 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:
    
    IOException - If bad things happen during the read operation
    
    Since:
    
    4.2

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Summary:
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Field |
Constr |
Method

Detail:
Field |
Constr |
Method

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

DEFAULT_SKIP_LINES

DEFAULT_MULTILINE_LIMIT

PASSTHROUGH_EXCEPTIONS

READ_AHEAD_LIMIT

parser

skipLines

br

lineReader

hasNext

linesSkipped

keepCR

verifyReader

multilineLimit

errorLocale

linesRead

recordsRead

peekedLine

peekedLines

Constructor Detail

CSVReader

Method Detail

getParser

getSkipLines

keepCarriageReturns

readAll

readNext

readNextSilently

validateResult

combineResultsFromMultipleReads

getNextLine

getMultilineLimit

isClosed

close

iterator

verifyReader

getLinesRead

getRecordsRead

skip

setErrorLocale

peek