org.apache.oozie.util

Class TimestampedMessageParser

java.lang.Object

org.apache.oozie.util.TimestampedMessageParser

Direct Known Subclasses:

SimpleTimestampedMessageParser

public class TimestampedMessageParser
extends Object

Encapsulates the parsing and filtering of the log messages from a BufferedReader. It makes sure not to read in the entire log into memory at the same time; at most, it will have two messages (which can be multi-line in the case of exception stack traces).

To use this class: Calling increment() will tell the parser to read the next message from the Reader. It will return true if there are more messages and false if not. Calling getLastMessage() and getLastTimestamp() will return the last message and timestamp, respectively, that were parsed when increment() was called. Calling processRemaining(java.io.Writer) will write the remaining log messages to the given Writer.

Field Summary

Fields

Modifier and Type	Field and Description
int	count
protected BufferedReader	reader

Constructor Summary

Constructors

Constructor and Description
TimestampedMessageParser(BufferedReader reader, XLogFilter filter) Creates a TimestampedMessageParser with the given BufferedReader and filter.

Method Summary

Methods

Modifier and Type	Method and Description
void	closeReader() Closes the Reader.
String	getLastMessage() Returns the message that was last parsed.
String	getLastTimestamp() Returns the timestamp from the last message that was parsed.
boolean	increment() Causes the next message and timestamp to be parsed from the BufferedReader.
protected String	parseNextLine() Reads the next line from the Reader and checks if it matches the filter.
void	processRemaining(Writer writer) Streams log messages to the passed in Writer, with default buffer len 4K and zero bytes already written
void	processRemaining(Writer writer, int bufferLen) Streams log messages to the passed in Writer, with zero bytes already written
void	processRemaining(Writer writer, int bufferLen, int bytesWritten) Streams log messages to the passed in Writer.

Methods inherited from class java.lang.Object

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

Field Detail

reader

protected BufferedReader reader

count

public int count

Constructor Detail

TimestampedMessageParser

public TimestampedMessageParser(BufferedReader reader,
                        XLogFilter filter)

Creates a TimestampedMessageParser with the given BufferedReader and filter.

Parameters:

reader - The BufferedReader to get the log messages from

filter - The filter

Method Detail

increment

public boolean increment()
                  throws IOException

Causes the next message and timestamp to be parsed from the BufferedReader.

Returns:

true if there are more messages left; false if not

Throws:

IOException - If there was a problem reading from the Reader

getLastTimestamp

public String getLastTimestamp()

Returns the timestamp from the last message that was parsed.

Returns:

the timestamp from the last message that was parsed

getLastMessage

public String getLastMessage()

Returns the message that was last parsed.

Returns:

the message that was last parsed

closeReader

public void closeReader()
                 throws IOException

Closes the Reader.

Throws:

IOException

parseNextLine

protected String parseNextLine()
                        throws IOException

Reads the next line from the Reader and checks if it matches the filter. It can also handle multi-line messages (i.e. exception stack traces). If it returns null, then there are no lines left in the Reader.

Returns:

The next line, or null

Throws:

IOException

processRemaining

public void processRemaining(Writer writer,
                    int bufferLen,
                    int bytesWritten)
                      throws IOException

Streams log messages to the passed in Writer. Flushes the log writing based on buffer len

Parameters:

writer -

bufferLen - maximum len of log buffer

bytesWritten - num bytes already written to writer

Throws:

IOException

processRemaining

public void processRemaining(Writer writer,
                    int bufferLen)
                      throws IOException

Streams log messages to the passed in Writer, with zero bytes already written

Parameters:

writer -

bufferLen - maximum len of log buffer

Throws:

IOException

processRemaining

public void processRemaining(Writer writer)
                      throws IOException

Streams log messages to the passed in Writer, with default buffer len 4K and zero bytes already written

Parameters:

writer -

Throws:

IOException