WALPrettyPrinter (Apache HBase 1.4.11 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.

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

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

- 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.
  - 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

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

WALPrettyPrinter

WALPrettyPrinter

Method Detail

enableValues

disableValues

enableJSON

disableJSON

setSequenceFilter

setRegionFilter

setRowFilter

beginPersistentOutput

endPersistentOutput

processFile

main

run

setPosition