org.apache.pig.data
Class AbstractTuple

java.lang.Object
  extended by org.apache.pig.data.AbstractTuple
All Implemented Interfaces:
Serializable, Comparable, Iterable<Object>, org.apache.hadoop.io.Writable, org.apache.hadoop.io.WritableComparable, Tuple
Direct Known Subclasses:
DefaultTuple, ExampleTuple, SchemaTuple, TargetedTuple

public abstract class AbstractTuple
extends Object
implements Tuple

This class provides a convenient base for Tuple implementations. This makes it easier to provide default implementations as the Tuple interface is evolved.

See Also:
Serialized Form

Field Summary
 
Fields inherited from interface org.apache.pig.data.Tuple
NOTNULL, NULL
 
Constructor Summary
AbstractTuple()
           
 
Method Summary
 boolean equals(Object other)
           
 byte getType(int fieldNum)
          Find the type of a given field.
 boolean isNull(int fieldNum)
          Find out if a given field is null.
 Iterator<Object> iterator()
           
 void reference(Tuple t)
          Make this tuple reference the contents of another.
 String toDelimitedString(String delim)
          Write a tuple of values into a string.
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.apache.pig.data.Tuple
append, get, getAll, getMemorySize, set, size
 
Methods inherited from interface org.apache.hadoop.io.Writable
readFields, write
 
Methods inherited from interface java.lang.Comparable
compareTo
 

Constructor Detail

AbstractTuple

public AbstractTuple()
Method Detail

iterator

public Iterator<Object> iterator()
Specified by:
iterator in interface Iterable<Object>

toString

public String toString()
Overrides:
toString in class Object

toDelimitedString

public String toDelimitedString(String delim)
                         throws ExecException
Write a tuple of values into a string. The output will be the result of calling toString on each of the values in the tuple.

Specified by:
toDelimitedString in interface Tuple
Parameters:
delim - Delimiter to use in the string.
Returns:
A string containing the tuple.
Throws:
ExecException - this is never thrown. This only exists for backwards compatability reasons.

getType

public byte getType(int fieldNum)
             throws ExecException
Find the type of a given field.

Specified by:
getType in interface Tuple
Parameters:
fieldNum - Number of field to get the type for.
Returns:
type, encoded as a byte value. The values are defined in DataType. If the field is null, then DataType.UNKNOWN will be returned.
Throws:
ExecException - if the field number is greater than or equal to the number of fields in the tuple.

isNull

public boolean isNull(int fieldNum)
               throws ExecException
Find out if a given field is null.

Specified by:
isNull in interface Tuple
Parameters:
fieldNum - Number of field to check for null.
Returns:
true if the field is null, false otherwise.
Throws:
ExecException - if the field number given is greater than or equal to the number of fields in the tuple.

equals

public boolean equals(Object other)
Overrides:
equals in class Object

reference

public void reference(Tuple t)
Description copied from interface: Tuple
Make this tuple reference the contents of another. This method does not copy the underlying data. It maintains references to the data from the original tuple (and possibly even to the data structure holding the data).

Specified by:
reference in interface Tuple
Parameters:
t - Tuple to reference.


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