org.apache.openjpa.kernel.exps
Class Coalesce

java.lang.Object
  extended by org.apache.openjpa.kernel.exps.Val
      extended by org.apache.openjpa.kernel.exps.Coalesce
All Implemented Interfaces:
Serializable, Value

public class Coalesce
extends Val

An in-memory representation of a coalesce expression

Author:
Catalina Wei
See Also:
Serialized Form

Constructor Summary
Coalesce(Val[] val)
          Constructor.
 
Method Summary
 void acceptVisit(ExpressionVisitor visitor)
          Accept a visit from a tree visitor.
protected  boolean compare(Object o1, Object o2)
          Compare the two values.
protected  Object eval(Object candidate, Object orig, StoreContext ctx, Object[] params)
          Return this value for the given candidate.
protected  Object eval(Object candidate, StoreContext ctx, Object[] params)
           
 Class getType()
          Return the expected type for this value, or Object if the type is unknown.
 Val[] getVal()
           
 void setImplicitType(Class type)
          Set the implicit type of the value, based on how it is used in the filter.
 
Methods inherited from class org.apache.openjpa.kernel.exps.Val
eval, evaluate, evaluate, getAlias, getMetaData, getName, getPath, getSelectAs, isAggregate, isVariable, isXPath, setAlias, setMetaData
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Coalesce

Coalesce(Val[] val)
Constructor.

Method Detail

eval

protected Object eval(Object candidate,
                      Object orig,
                      StoreContext ctx,
                      Object[] params)
Description copied from class: Val
Return this value for the given candidate.

Specified by:
eval in class Val

eval

protected Object eval(Object candidate,
                      StoreContext ctx,
                      Object[] params)

compare

protected boolean compare(Object o1,
                          Object o2)
Compare the two values.


getVal

public Val[] getVal()

getType

public Class getType()
Description copied from interface: Value
Return the expected type for this value, or Object if the type is unknown.


setImplicitType

public void setImplicitType(Class type)
Description copied from interface: Value
Set the implicit type of the value, based on how it is used in the filter. This method is only called on values who return Object from Value.getType().


acceptVisit

public void acceptVisit(ExpressionVisitor visitor)
Description copied from interface: Value
Accept a visit from a tree visitor.

Specified by:
acceptVisit in interface Value
Overrides:
acceptVisit in class Val


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