WALPrettyPrinter (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.wal.WALPrettyPrinter

Direct Known Subclasses:

HLogPrettyPrinter
```
@InterfaceAudience.LimitedPrivate(value="Tools")
@InterfaceStability.Evolving
public class WALPrettyPrinter
extends Object
```
WALPrettyPrinter prints the contents of a given WAL with a variety of options affecting formatting and extent of content. It targets two usage cases: pretty printing for ease of debugging directly by humans, and JSON output for consumption by monitoring and/or maintenance scripts. It can filter by row, region, or sequence id. It can also toggle output of values.

Field Summary

Fields
Modifier and Type	Field and Description
`private boolean`	`firstTxn`
`private static org.codehaus.jackson.map.ObjectMapper`	`MAPPER`
`private PrintStream`	`out`
`private boolean`	`outputJSON`
`private boolean`	`outputValues`
`private boolean`	`persistentOutput`
`private long`	`position`
`private String`	`region`
`private String`	`row`
`private long`	`sequence`

Constructor Summary

Constructors
Constructor and Description
`WALPrettyPrinter()` Basic constructor that simply initializes values to reasonable defaults.
`WALPrettyPrinter(boolean outputValues, boolean outputJSON, long sequence, String region, String row, boolean persistentOutput, PrintStream out)` Fully specified constructor.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`beginPersistentOutput()` enables output as a single, persistent list.
`void`	`disableJSON()` turns JSON output off, and turns on "pretty strings" for human consumption
`void`	`disableValues()` turns value output off
`void`	`enableJSON()` turns JSON output on
`void`	`enableValues()` turns value output on
`void`	`endPersistentOutput()` ends output of a single, persistent list.
`static void`	`main(String[] args)`
`void`	`processFile(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.fs.Path p)` reads a log file and outputs its contents, one transaction at a time, as specified by the currently configured options
`static void`	`run(String[] args)` Pass one or more log file names and formatting options and it will dump out a text version of the contents on `stdout`.
`void`	`setPosition(long position)`
`void`	`setRegionFilter(String region)` sets the region by which output will be filtered
`void`	`setRowFilter(String row)` sets the region by which output will be filtered
`void`	`setSequenceFilter(long sequence)` sets the region by which output will be filtered
`private static Map<String,Object>`	`toStringMap(Cell cell)`

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

- Field Detail
  - outputValues
```
private boolean outputValues
```
  - outputJSON
```
private boolean outputJSON
```
  - sequence
```
private long sequence
```
  - region
```
private String region
```
  - row
```
private String row
```
  - persistentOutput
```
private boolean persistentOutput
```
  - firstTxn
```
private boolean firstTxn
```
  - out
```
private PrintStream out
```
  - MAPPER
```
private static final org.codehaus.jackson.map.ObjectMapper MAPPER
```
  - position
```
private long position
```
- Constructor Detail
  - WALPrettyPrinter
```
public WALPrettyPrinter()
```
    Basic constructor that simply initializes values to reasonable defaults.
  - WALPrettyPrinter
```
public WALPrettyPrinter(boolean outputValues,
                boolean outputJSON,
                long sequence,
                String region,
                String row,
                boolean persistentOutput,
                PrintStream out)
```
    Fully specified constructor.
    
    Parameters:
    outputValues - when true, enables output of values along with other log information
    outputJSON - when true, enables output in JSON format rather than a "pretty string"
    sequence - when nonnegative, serves as a filter; only log entries with this sequence id will be printed
    region - when not null, serves as a filter; only log entries from this region will be printed
    row - when not null, serves as a filter; only log entries from this row will be printed
    persistentOutput - keeps a single list running for multiple files. if enabled, the endPersistentOutput() method must be used!
    out - Specifies an alternative to stdout for the destination of this PrettyPrinter's output.
- Method Detail
  - enableValues
```
public void enableValues()
```
    turns value output on
  - disableValues
```
public void disableValues()
```
    turns value output off
  - enableJSON
```
public void enableJSON()
```
    turns JSON output on
  - disableJSON
```
public void disableJSON()
```
    turns JSON output off, and turns on "pretty strings" for human consumption
  - setSequenceFilter
```
public void setSequenceFilter(long sequence)
```
    sets the region by which output will be filtered
    
    Parameters:
    sequence - when nonnegative, serves as a filter; only log entries with this sequence id will be printed
  - setRegionFilter
```
public void setRegionFilter(String region)
```
    sets the region by which output will be filtered
    
    Parameters:
    region - when not null, serves as a filter; only log entries from this region will be printed
  - setRowFilter
```
public void setRowFilter(String row)
```
    sets the region by which output will be filtered
    
    Parameters:
    row - when not null, serves as a filter; only log entries from this row will be printed
  - beginPersistentOutput
```
public void beginPersistentOutput()
```
    enables output as a single, persistent list. at present, only relevant in the case of JSON output.
  - endPersistentOutput
```
public void endPersistentOutput()
```
    ends output of a single, persistent list. at present, only relevant in the case of JSON output.
  - processFile
```
public void processFile(org.apache.hadoop.conf.Configuration conf,
               org.apache.hadoop.fs.Path p)
                 throws IOException
```
    reads a log file and outputs its contents, one transaction at a time, as specified by the currently configured options
    
    Parameters:
    conf - the HBase configuration relevant to this log file
    p - the path of the log file to be read
    
    Throws:
    
    IOException - may be unable to access the configured filesystem or requested file.
  - toStringMap
```
private static Map<String,Object> toStringMap(Cell cell)
```
  - main
```
public static void main(String[] args)
                 throws IOException
```
    Throws:
    
    IOException
  - run
```
public static void run(String[] args)
                throws IOException
```
    Pass one or more log file names and formatting options and it will dump out a text version of the contents on stdout.
    
    Parameters:
    args - Command line arguments
    
    Throws:
    
    IOException - Thrown upon file system errors etc.
  - setPosition
```
public void setPosition(long position)
```

Class WALPrettyPrinter

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

outputValues

outputJSON

sequence

region

row

persistentOutput

firstTxn

out

MAPPER

position

Constructor Detail

WALPrettyPrinter

WALPrettyPrinter

Method Detail

enableValues

disableValues

enableJSON

disableJSON

setSequenceFilter

setRegionFilter

setRowFilter

beginPersistentOutput

endPersistentOutput

processFile

toStringMap

main

run

setPosition