mondrian.test.loader

Class CsvLoader

java.lang.Object

mondrian.test.loader.CsvLoader

public class CsvLoader
extends Object

This is a basic Comma-separated-value (CSV, Csv) reader. As input it ultimately takes a java.io.Reader but has helper support for java.io.InputStream, file names and java.io.File. One can also specify a separator character other than the default comma, ',', character and, also, that the input's first line contains the names of the columns (by default this is not assumed). Lastly, this supports only the comment character '#' and only at the start of a line. This comment support could be generalized but that task is left to others.

To use this class one gives it a java.io.Reader and then calls the hasNextLine and nextLine methods much like a java.io.Iterator but in this case the nextLine method returns a String[] holding the, possibly null, values of the parsed next line. The size of the String[] is the size of the first line parsed that contains the separator character (comment lines are not used). If the number of separator characters in subsequent lines is less than the initial numbers, the trailing entries in the String[] returned by the nextLine method are null. On the other hand, if there are more separator characters in a subsequent line, the world ends with an IndexOutOfBoundsException (sorry, making this more graceful is also a task for others). When one is through using a CsvLoader instance one should call the close method (which closes the Reader).

All well and good, but there are two additional methods that can be used to extend the capabilities of this CSV parser, the nextSet and putBack methods. With these methods one can, basically, reset the CsvLoader to a state where it does not yet know how many separator characters to expect per line (while stay at the current line in the Reader). The nextSet (next set of CSV lines) resets the loader while the putBack method can be used to place the last line returned back into loader. These methods are used in CsvDBLoader allowing one to have multiple sets of CSV rows with differing number of values per sets.

There are six special start/end characters when seen prevent the recognition of both the separator character and new lines:

    double quotes: "" ""
    single quotes: '  '
    bracket: i     [ ]
    parenthesis:   ()
    braces:        { }
    chevrons:      < >
 

Its certainly not the penultimate such parser but its hoped that its adequate.

Author:

Richard M. Emberson

Field Summary

Fields

Modifier and Type	Field and Description
static char	BRACES_END
static char	BRACES_START
static char	BRACKET_END
static char	BRACKET_START
static char	CHEVRON_END
static char	CHEVRON_START
static char	DEFAULT_SEPARATOR
static char	DOUBLE_QUOTE
protected static org.apache.log4j.Logger	LOGGER
static char	PAREN_END
static char	PAREN_START
static char	SINGLE_QUOTE

Constructor Summary

Constructors

Constructor and Description
CsvLoader(File file)
CsvLoader(File file, char separator, boolean includesHeader)
CsvLoader(InputStream in)
CsvLoader(InputStream in, char separator, boolean includesHeader)
CsvLoader(InputStream in, char separator, boolean includesHeader, String charset)
CsvLoader(InputStream in, String charset)
CsvLoader(Reader reader)
CsvLoader(Reader reader, char separator, boolean includesHeader)
CsvLoader(String filename)
CsvLoader(String filename, char separator, boolean includesHeader)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
String[]	getColumnNames()
int	getNextSetCount()
boolean	hasNextLine()
boolean	inComment()
protected void	initialize()
static void	main(String[] args)
protected String[]	nextColumns()
String[]	nextLine()
void	nextSet()
void	putBack(String[] columns)
protected void	recordInCommentLine(String line)

Methods inherited from class java.lang.Object

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

Field Detail

LOGGER

protected static final org.apache.log4j.Logger LOGGER

DEFAULT_SEPARATOR

public static final char DEFAULT_SEPARATOR

See Also:

Constant Field Values

DOUBLE_QUOTE

public static final char DOUBLE_QUOTE

See Also:

Constant Field Values

SINGLE_QUOTE

public static final char SINGLE_QUOTE

See Also:

Constant Field Values

BRACKET_START

public static final char BRACKET_START

See Also:

Constant Field Values

BRACKET_END

public static final char BRACKET_END

See Also:

Constant Field Values

PAREN_START

public static final char PAREN_START

See Also:

Constant Field Values

PAREN_END

public static final char PAREN_END

See Also:

Constant Field Values

BRACES_START

public static final char BRACES_START

See Also:

Constant Field Values

BRACES_END

public static final char BRACES_END

See Also:

Constant Field Values

CHEVRON_START

public static final char CHEVRON_START

See Also:

Constant Field Values

CHEVRON_END

public static final char CHEVRON_END

See Also:

Constant Field Values

Constructor Detail

CsvLoader

public CsvLoader(InputStream in,
         String charset)
          throws UnsupportedEncodingException

Throws:

UnsupportedEncodingException

CsvLoader

public CsvLoader(InputStream in,
         char separator,
         boolean includesHeader,
         String charset)
          throws UnsupportedEncodingException

Throws:

UnsupportedEncodingException

CsvLoader

public CsvLoader(InputStream in)

CsvLoader

public CsvLoader(InputStream in,
         char separator,
         boolean includesHeader)

CsvLoader

public CsvLoader(String filename)
          throws FileNotFoundException

Throws:

FileNotFoundException

CsvLoader

public CsvLoader(String filename,
         char separator,
         boolean includesHeader)
          throws FileNotFoundException

Throws:

FileNotFoundException

CsvLoader

public CsvLoader(File file)
          throws FileNotFoundException

Throws:

FileNotFoundException

CsvLoader

public CsvLoader(File file,
         char separator,
         boolean includesHeader)
          throws FileNotFoundException

Throws:

FileNotFoundException

CsvLoader

public CsvLoader(Reader reader)

CsvLoader

public CsvLoader(Reader reader,
         char separator,
         boolean includesHeader)

Method Detail

initialize

protected void initialize()
                   throws IOException

Throws:

IOException

getColumnNames

public String[] getColumnNames()
                        throws IOException

Throws:

IOException

inComment

public boolean inComment()

hasNextLine

public boolean hasNextLine()
                    throws IOException

Throws:

IOException

nextLine

public String[] nextLine()

getNextSetCount

public int getNextSetCount()

nextSet

public void nextSet()

putBack

public void putBack(String[] columns)

close

public void close()
           throws IOException

Throws:

IOException

nextColumns

protected String[] nextColumns()
                        throws IOException

Throws:

IOException

recordInCommentLine

protected void recordInCommentLine(String line)

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception