TableInputFormatBase (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.mapred.TableInputFormatBase

All Implemented Interfaces:: org.apache.hadoop.mapred.InputFormat<ImmutableBytesWritable,Result>

Direct Known Subclasses:: TableInputFormat

@InterfaceAudience.Public
@InterfaceStability.Stable
public abstract class TableInputFormatBase
extends Object
implements org.apache.hadoop.mapred.InputFormat<ImmutableBytesWritable,Result>

A Base for TableInputFormats. Receives a HTable, a byte[] of input columns and optionally a Filter. Subclasses may use other TableRecordReader implementations. Subclasses MUST ensure initializeTable(Connection, TableName) is called for an instance to function properly. Each of the entry points to this class used by the MapReduce framework, getRecordReader(InputSplit, JobConf, Reporter) and getSplits(JobConf, int), will call initialize(JobConf) as a convenient centralized location to handle retrieving the necessary configuration information. If your subclass overrides either of these methods, either call the parent version or call initialize yourself.

An example of a subclass:

   class ExampleTIF extends TableInputFormatBase {

     @Override
     protected void initialize(JobConf context) throws IOException {
       // We are responsible for the lifecycle of this connection until we hand it over in
       // initializeTable.
       Connection connection =
          ConnectionFactory.createConnection(HBaseConfiguration.create(job));
       TableName tableName = TableName.valueOf("exampleTable");
       // mandatory. once passed here, TableInputFormatBase will handle closing the connection.
       initializeTable(connection, tableName);
       byte[][] inputColumns = new byte [][] { Bytes.toBytes("columnA"),
         Bytes.toBytes("columnB") };
       // mandatory
       setInputColumns(inputColumns);
       // optional, by default we'll get everything for the given columns.
       Filter exampleFilter = new RowFilter(CompareOp.EQUAL, new RegexStringComparator("aa.*"));
       setRowFilter(exampleFilter);
     }
   }

Constructor Summary

Constructors
Constructor and Description

TableInputFormatBase()

Constructors
Constructor and Description
`TableInputFormatBase()`

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`closeTable()` Close the Table and related objects that were initialized via `initializeTable(Connection, TableName)`.
`protected HTable`	`getHTable()` Deprecated. use `getTable()`
`org.apache.hadoop.mapred.RecordReader<ImmutableBytesWritable,Result>`	`getRecordReader(org.apache.hadoop.mapred.InputSplit split, org.apache.hadoop.mapred.JobConf job, org.apache.hadoop.mapred.Reporter reporter)` Builds a TableRecordReader.
`org.apache.hadoop.mapred.InputSplit[]`	`getSplits(org.apache.hadoop.mapred.JobConf job, int numSplits)` Calculates the splits that will serve as input for the map tasks.
`protected Table`	`getTable()` Allows subclasses to get the `Table`.
`protected void`	`initialize(org.apache.hadoop.mapred.JobConf job)` Handle subclass specific set up.
`protected void`	`initializeTable(Connection connection, TableName tableName)` Allows subclasses to initialize the table information.
`protected void`	`setHTable(HTable table)` Deprecated. use `initializeTable(Connection,TableName)`
`protected void`	`setInputColumns(byte[][] inputColumns)`
`protected void`	`setRowFilter(Filter rowFilter)` Allows subclasses to set the `Filter` to be used.
`protected void`	`setTableRecordReader(TableRecordReader tableRecordReader)` Allows subclasses to set the `TableRecordReader`.

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

- Constructor Detail
  - TableInputFormatBase
```
public TableInputFormatBase()
```
- Method Detail
  - getRecordReader
```
public org.apache.hadoop.mapred.RecordReader<ImmutableBytesWritable,Result> getRecordReader(org.apache.hadoop.mapred.InputSplit split,
                                                                                   org.apache.hadoop.mapred.JobConf job,
                                                                                   org.apache.hadoop.mapred.Reporter reporter)
                                                                                     throws IOException
```
    Builds a TableRecordReader. If no TableRecordReader was provided, uses the default.
    
    Specified by:
    
    getRecordReader in interface org.apache.hadoop.mapred.InputFormat<ImmutableBytesWritable,Result>
    
    Throws:
    
    IOException
    See Also:
    InputFormat.getRecordReader(InputSplit, JobConf, Reporter)
  - getSplits
```
public org.apache.hadoop.mapred.InputSplit[] getSplits(org.apache.hadoop.mapred.JobConf job,
                                              int numSplits)
                                                throws IOException
```
    Calculates the splits that will serve as input for the map tasks. Splits are created in number equal to the smallest between numSplits and the number of HRegions in the table. If the number of splits is smaller than the number of HRegions then splits are spanned across multiple HRegions and are grouped the most evenly possible. In the case splits are uneven the bigger splits are placed first in the InputSplit array.
    
    Specified by:
    
    getSplits in interface org.apache.hadoop.mapred.InputFormat<ImmutableBytesWritable,Result>
    
    Parameters:
    job - the map task JobConf
    numSplits - a hint to calculate the number of splits (mapred.map.tasks).
    
    Returns:
    the input splits
    
    Throws:
    
    IOException
    See Also:
    InputFormat.getSplits(org.apache.hadoop.mapred.JobConf, int)
  - initializeTable
```
protected void initializeTable(Connection connection,
                   TableName tableName)
                        throws IOException
```
    Allows subclasses to initialize the table information.
    
    Parameters:
    connection - The Connection to the HBase cluster. MUST be unmanaged. We will close.
    tableName - The TableName of the table to process.
    
    Throws:
    
    IOException
  - setInputColumns
```
protected void setInputColumns(byte[][] inputColumns)
```
    Parameters:
    inputColumns - to be passed in Result to the map task.
  - getHTable
```
@Deprecated
protected HTable getHTable()
```
    Deprecated. use getTable()
    
    Allows subclasses to get the HTable.
  - getTable
```
protected Table getTable()
```
    Allows subclasses to get the Table.
  - setHTable
```
@Deprecated
protected void setHTable(HTable table)
```
    Deprecated. use initializeTable(Connection,TableName)
    
    Allows subclasses to set the HTable.
    
    Parameters:
    table - to get the data from
  - setTableRecordReader
```
protected void setTableRecordReader(TableRecordReader tableRecordReader)
```
    Allows subclasses to set the TableRecordReader.
    
    Parameters:
    tableRecordReader - to provide other TableRecordReader implementations.
  - setRowFilter
```
protected void setRowFilter(Filter rowFilter)
```
    Allows subclasses to set the Filter to be used.
    
    Parameters:
    rowFilter -
  - initialize
```
protected void initialize(org.apache.hadoop.mapred.JobConf job)
                   throws IOException
```
    Handle subclass specific set up. Each of the entry points used by the MapReduce framework, getRecordReader(InputSplit, JobConf, Reporter) and getSplits(JobConf, int), will call initialize(JobConf) as a convenient centralized location to handle retrieving the necessary configuration information and calling initializeTable(Connection, TableName). Subclasses should implement their initialize call such that it is safe to call multiple times. The current TableInputFormatBase implementation relies on a non-null table reference to decide if an initialize call is needed, but this behavior may change in the future. In particular, it is critical that initializeTable not be called multiple times since this will leak Connection instances.
    
    Throws:
    
    IOException
  - closeTable
```
protected void closeTable()
                   throws IOException
```
    Close the Table and related objects that were initialized via initializeTable(Connection, TableName).
    
    Throws:
    
    IOException

Class TableInputFormatBase

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

TableInputFormatBase

Method Detail

getRecordReader

getSplits

initializeTable

setInputColumns

getHTable

getTable

setHTable

setTableRecordReader

setRowFilter

initialize

closeTable