stream.io

Class CsvWriter

java.lang.Object

stream.AbstractProcessor

stream.ConditionedProcessor

stream.io.AbstractWriter

stream.io.CsvWriter

All Implemented Interfaces:

Processor, Service, StatefulProcessor

Direct Known Subclasses:

SvmLightWriter

public class CsvWriter
extends AbstractWriter
implements Service

This class implements a simple CSV output writer. The default separator is a semicolon. The class extends AbstractWriter, which in turn implements the ConditionedProcessor interface. Thus, it is possible to specify conditions to the items that shall be written out as CSV.

Author:

Christian Bockermann

Field Summary

Fields

Modifier and Type	Field and Description
protected Boolean	append
protected boolean	closed
protected File	file
protected Expression<String>	fileExpression
protected String	filter
protected boolean	header
protected List<String>	headers
protected boolean	headerWritten
protected String	lastHeader
protected String	lastUrlString
(package private) static org.slf4j.Logger	log
protected PrintStream	p
protected String	separator
protected URL	url
protected String	urlString

Fields inherited from class stream.io.AbstractWriter

keys

Fields inherited from class stream.ConditionedProcessor

condition

Fields inherited from class stream.AbstractProcessor

context

Constructor Summary

Constructors

Constructor and Description
CsvWriter()
CsvWriter(File file) Create a new DataStreamWriter which writes all data to the given file.
CsvWriter(File file, String separator)
CsvWriter(OutputStream out)
CsvWriter(OutputStream out, String separator)
CsvWriter(URL url)

Method Summary

Modifier and Type	Method and Description
protected String	createHeader(Data item)
void	finish()
Boolean	getAppend()
List<String>	getHeaderNames()
String	getSeparator()
String	getUrl()
void	init(ProcessContext ctx)
boolean	isHeader()
Data	processMatchingData(Data datum)
void	reset()
void	setAppend(Boolean append)
void	setAttributeFilter(String filter)
void	setHeader(boolean header)
void	setSeparator(String separator)
void	setUrl(String url)
void	write(Data datum) This method is actually responsible for writing the data item to the output stream in the format that the implementing class supports.
void	writeHeader(Data datum)

Methods inherited from class stream.io.AbstractWriter

getKeys, selectedKeys, setKeys

Methods inherited from class stream.ConditionedProcessor

getCondition, matches, process, setCondition

Methods inherited from class stream.AbstractProcessor

resetState

Methods inherited from class java.lang.Object

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

Field Detail

log

static org.slf4j.Logger log

p

protected PrintStream p

separator

protected String separator

lastHeader

protected String lastHeader

headerWritten

protected boolean headerWritten

filter

protected String filter

headers

protected List<String> headers

closed

protected boolean closed

urlString

protected String urlString

url

protected URL url

file

protected File file

lastUrlString

protected String lastUrlString

fileExpression

protected Expression<String> fileExpression

header

protected boolean header

append

protected Boolean append

Constructor Detail

CsvWriter

public CsvWriter()

CsvWriter

public CsvWriter(URL url)
          throws Exception

Throws:

Exception

CsvWriter

public CsvWriter(File file)
          throws IOException

Create a new DataStreamWriter which writes all data to the given file.

Parameters:

file -

Throws:

IOException

CsvWriter

public CsvWriter(OutputStream out)

Parameters:

out -

CsvWriter

public CsvWriter(OutputStream out,
                 String separator)

CsvWriter

public CsvWriter(File file,
                 String separator)
          throws IOException

Throws:

IOException

Method Detail

setUrl

@Parameter(required=true,
           description="The url to write to.")
public void setUrl(String url)

Overrides:

setUrl in class AbstractWriter

Parameters:

url - the url to set

getUrl

public String getUrl()

Overrides:

getUrl in class AbstractWriter

Returns:

the url

setAttributeFilter

public void setAttributeFilter(String filter)

getHeaderNames

public List<String> getHeaderNames()

getSeparator

public String getSeparator()

Returns:

the separator

setSeparator

@Parameter(required=false,
           description="The separator to separate columns, usually \',\'",
           defaultValue=",")
public void setSeparator(String separator)

Parameters:

separator - the separator to set

isHeader

public boolean isHeader()

setHeader

public void setHeader(boolean header)

getAppend

public Boolean getAppend()

setAppend

public void setAppend(Boolean append)

init

public void init(ProcessContext ctx)
          throws Exception

Specified by:

init in interface StatefulProcessor

Overrides:

init in class AbstractProcessor

Throws:

Exception

processMatchingData

public Data processMatchingData(Data datum)

Overrides:

processMatchingData in class AbstractWriter

See Also:

stream.io.DataStreamListener#dataArrived(java.util.Map)

writeHeader

public void writeHeader(Data datum)

write

public void write(Data datum)

Description copied from class: AbstractWriter

This method is actually responsible for writing the data item to the output stream in the format that the implementing class supports.

Specified by:

write in class AbstractWriter

createHeader

protected String createHeader(Data item)

finish

public void finish()
            throws Exception

Specified by:

finish in interface StatefulProcessor

Overrides:

finish in class AbstractProcessor

Throws:

Exception

reset

public void reset()
           throws Exception

Specified by:

reset in interface Service

Throws:

Exception