org.teiid.query.sql.symbol
Class Symbol

java.lang.Object
  org.teiid.query.sql.symbol.Symbol

All Implemented Interfaces:

java.lang.Cloneable, LanguageObject

Direct Known Subclasses:

GroupSymbol, SelectSymbol

public abstract class Symbol
extends java.lang.Object
implements LanguageObject

This is the server's representation of a metadata symbol. The only thing a symbol has to have is a name. This name relates only to how a symbol is specified in a user's query and does not necessarily relate to any actual metadata identifier (although it may). Subclasses of this class provide specialized instances of symbol for various circumstances in a user's query. In the context of a single query, a symbol's name has a unique meaning although it may be used more than once in some circumstances.

Nested Class Summary

Nested classes/interfaces inherited from interface org.teiid.query.sql.LanguageObject

LanguageObject.Util

Field Summary

protected java.lang.String

outputName Prior to resolving null, after resolving it is the exact string entered in the query.

Constructor Summary

	Symbol(java.lang.String name) Construct a symbol with a name.
protected	Symbol(java.lang.String name, java.lang.String canonicalName) Constructor to be used for cloning instances.

Method Summary

abstract java.lang.Object	clone() Return a copy of this object.
boolean	equals(java.lang.Object obj) Compare the symbol based ONLY on name.
protected java.lang.String	getCanonical()
java.lang.String	getCanonicalName() Get canonical name for comparisons
java.lang.String	getName() Get the name of the symbol
java.lang.String	getOutputName()
java.lang.String	getShortCanonicalName() Get the short name of the element
java.lang.String	getShortName() Get the short name of the element
int	hashCode() Return a hash code for this symbol.
abstract boolean	isResolved() Returns true if this symbol has been completely resolved with respect to actual runtime metadata.
protected void	setName(java.lang.String name)
void	setOutputName(java.lang.String outputName)
void	setShortCanonicalName(java.lang.String shortCanonicalName)
void	setShortName(java.lang.String name) Change the symbol's name.
java.lang.String	toString() Returns string representation of this symbol.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.teiid.query.sql.LanguageObject

acceptVisitor

Field Detail

outputName

protected java.lang.String outputName

Prior to resolving null, after resolving it is the exact string entered in the query. The AliasGenerator can also set this value as necessary for the data tier.

Constructor Detail

Symbol

protected Symbol(java.lang.String name,
                 java.lang.String canonicalName)

Constructor to be used for cloning instances. Calls to String.toUpperCase() to generate the canonical names were the big performance hit during cloning, so this method allows subclasses to simply pass in the canonical name to avoid toUpperCase().

Parameters:

name -

canonicalName -

Since:

4.3

Symbol

public Symbol(java.lang.String name)

Construct a symbol with a name.

Parameters:

name - Name of the symbol

Throws:

java.lang.IllegalArgumentException - If name is null

Method Detail

setName

protected void setName(java.lang.String name)

setShortName

public void setShortName(java.lang.String name)

Change the symbol's name. This will change the symbol's hash code and canonical name!!!!!!!!!!!!!!!!! If this symbol is in a hashed collection, it will be lost!

Parameters:

name - New name

getName

public java.lang.String getName()

Get the name of the symbol

Returns:

Name of the symbol, never null

getCanonicalName

public java.lang.String getCanonicalName()

Get canonical name for comparisons

Returns:

Canonical name for comparisons

setShortCanonicalName

public void setShortCanonicalName(java.lang.String shortCanonicalName)

isResolved

public abstract boolean isResolved()

Returns true if this symbol has been completely resolved with respect to actual runtime metadata. A resolved symbol has been validated that it refers to actual metadata and will have references to the real metadata IDs if necessary. Different types of symbols determine their resolution in different ways, so this method is abstract and must be implemented by subclasses.

Returns:

True if resolved with runtime metadata

toString

public java.lang.String toString()

Returns string representation of this symbol.

Overrides:

toString in class java.lang.Object

Returns:

String representing the symbol

hashCode

public int hashCode()

Return a hash code for this symbol.

Overrides:

hashCode in class java.lang.Object

Returns:

Hash code

equals

public boolean equals(java.lang.Object obj)

Compare the symbol based ONLY on name. Symbols are not compared based on their underlying physical metadata IDs but rather on their representation in the context of a particular query. Case is not important when comparing symbol names.

Overrides:

equals in class java.lang.Object

Parameters:

obj - Other object

Returns:

True if other obj is a Symbol (or subclass) and name is equal

clone

public abstract java.lang.Object clone()

Return a copy of this object.

Specified by:

clone in interface LanguageObject

Overrides:

clone in class java.lang.Object

Returns:

Deep clone of this object

getCanonical

protected final java.lang.String getCanonical()

getOutputName

public java.lang.String getOutputName()

setOutputName

public void setOutputName(java.lang.String outputName)

getShortName

public final java.lang.String getShortName()

Get the short name of the element

Returns:

Short name of the symbol (un-dotted)

getShortCanonicalName

public final java.lang.String getShortCanonicalName()

Get the short name of the element

Returns:

Short name of the symbol (un-dotted)