org.apache.jdo.impl.jdoql.tree
Class FilterExpressionDumper

java.lang.Object
  org.apache.jdo.jdoql.tree.AbstractNodeVisitor
      org.apache.jdo.impl.jdoql.tree.FilterExpressionDumper

All Implemented Interfaces:

NodeVisitor

public class FilterExpressionDumper

extends AbstractNodeVisitor

An instance of this class is used to print a query tree into a print stream. The tree is printed as a string representation. The filter of this representation can be used as argument for method Query.setFilter. As this class inherits from AbstractNodeVisitor, it only overwrites those methods that need to dump and relies on the delegation mechanism for the remaining methods implemented in AbstractNodeVisitor .

Author:

Michael Watzek

Field Summary

(package private) java.io.PrintStream

out

Constructor Summary

FilterExpressionDumper()
Constructs an instance of this class.

FilterExpressionDumper(java.io.PrintStream out)
Constructs an instance of this class.

Method Summary

void	arrive(AscendingOrderingExpression node) Ascending ordering expressions are dumped like Ascending(expression).
protected void	arrive(BinaryExpression node) Binary expressions are dumped in parenthesized manner.
void	arrive(CastExpression node) Cast expressions are dumped like (type)expression.
void	arrive(ComplementExpression node) Complement expressions are dumped like ~expression.
void	arrive(ConstantExpression node) Dumps the value of the argument node.
void	arrive(DescendingOrderingExpression node) Descending ordering expressions are dumped like Descending(expression).
void	arrive(FieldAccessExpression node) Field access expressions are dumped like target.fieldName.
void	arrive(IdentifierExpression node) Dumps the name of an identifier expression.
void	arrive(NotExpression node) Dumps a not expression.
void	arrive(UnaryMinusExpression node) Unary minus expressions are dumped like -expression.
protected java.lang.Object	leave(BinaryExpression node, java.lang.Object[] results) Binary expressions are dumped in parenthesized manner.
java.lang.Object	leave(FieldAccessExpression node, java.lang.Object[] results) Field access expressions are dumped like target.fieldName.
protected java.lang.Object	leave(MethodCallExpression node, java.lang.Object[] results) Method call expressions are dumped like target.methodName(arguments).
protected java.lang.Object	leave(OrderingExpression node, java.lang.Object[] results) Ordering expressions are dumped like Ascending/Descending(expression).
java.lang.Object	leave(QueryTree node, java.lang.Object[] results) Query trees are dumped like orderingExpressions, filterExpression.
boolean	walkNextChild(AndExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A logical and expression is dumped like (leftExpression & rightExpression).
boolean	walkNextChild(ConditionalAndExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A conditional and expression is dumped like (leftExpression && rightExpression).
boolean	walkNextChild(ConditionalOrExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A logical or expression is dumped like (leftExpression || rightExpression).
boolean	walkNextChild(DivideExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A divide expression is dumped like (leftExpression / rightExpression).
boolean	walkNextChild(EqualsExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) An equals expression is dumped like (leftExpression == rightExpression).
boolean	walkNextChild(GreaterThanEqualsExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A greater than equals expression is dumped like (leftExpression >= rightExpression).
boolean	walkNextChild(GreaterThanExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A greater than expression is dumped like (leftExpression > rightExpression).
boolean	walkNextChild(LessThanEqualsExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A less than equals expression is dumped like (leftExpression <= rightExpression).
boolean	walkNextChild(LessThanExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A less than expression is dumped like (leftExpression < rightExpression).
protected boolean	walkNextChild(MethodCallExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) Method call expressions are dumped like target.methodName(arguments).
boolean	walkNextChild(MinusExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A minus expression is dumped like (leftExpression - rightExpression).
boolean	walkNextChild(NotEqualsExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) Dumps a not equals expression.
boolean	walkNextChild(OrExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A logical or expression is dumped like (leftExpression | rightExpression).
boolean	walkNextChild(PlusExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A plus expression is dumped like (leftExpression + rightExpression).
boolean	walkNextChild(QueryTree node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) Query trees are dumped like orderingExpressions, filterExpression.
boolean	walkNextChild(TimesExpression node, java.lang.Object resultOfPreviousChild, int indexOfNextChild) A times expression is dumped like (leftExpression * rightExpression).

Methods inherited from class org.apache.jdo.jdoql.tree.AbstractNodeVisitor

arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, arrive, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, leave, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild, walkNextChild

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

out

final java.io.PrintStream out

Constructor Detail

FilterExpressionDumper

public FilterExpressionDumper()

Constructs an instance of this class. The print stream used to dump the tree is System.out.

FilterExpressionDumper

public FilterExpressionDumper(java.io.PrintStream out)

Constructs an instance of this class. The print stream used to dump the tree is the argument out.

Parameters:

out - the print stream to dump to

Method Detail

arrive

protected void arrive(BinaryExpression node)

Binary expressions are dumped in parenthesized manner. Thus, this method dumps the left parenthesis and it's corresponding leave method dumps the right parenthesis.

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

leave

protected java.lang.Object leave(BinaryExpression node,
                                 java.lang.Object[] results)

Binary expressions are dumped in parenthesized manner. Thus, this method dumps the right parenthesis and it's corresponding leave method dumps the left parenthesis.

Overrides:

leave in class AbstractNodeVisitor

Parameters:

node - the node to dump

results - an array of null instances

Returns:

null

leave

protected java.lang.Object leave(MethodCallExpression node,
                                 java.lang.Object[] results)

Method call expressions are dumped like target.methodName(arguments).

Overrides:

leave in class AbstractNodeVisitor

Parameters:

node - the node to dump

results - an array of null instances

Returns:

null

leave

protected java.lang.Object leave(OrderingExpression node,
                                 java.lang.Object[] results)

Ordering expressions are dumped like Ascending/Descending(expression).

Overrides:

leave in class AbstractNodeVisitor

Parameters:

node - the node to dump

results - an array of null instances

Returns:

null

walkNextChild

protected boolean walkNextChild(MethodCallExpression node,
                                java.lang.Object resultOfPreviousChild,
                                int indexOfNextChild)

Method call expressions are dumped like target.methodName(arguments).

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - the result of the previsous child node

indexOfNextChild - the index of the next child to be dumped

Returns:

true

arrive

public void arrive(AscendingOrderingExpression node)

Ascending ordering expressions are dumped like Ascending(expression).

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(DescendingOrderingExpression node)

Descending ordering expressions are dumped like Descending(expression).

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(ConstantExpression node)

Dumps the value of the argument node. If that node holds a String instance, then the string value is dumped in double quotes.

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(CastExpression node)

Cast expressions are dumped like (type)expression.

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(FieldAccessExpression node)

Field access expressions are dumped like target.fieldName.

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(ComplementExpression node)

Complement expressions are dumped like ~expression.

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(IdentifierExpression node)

Dumps the name of an identifier expression.

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(NotExpression node)

Dumps a not expression. It is dumped like !expression.

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

arrive

public void arrive(UnaryMinusExpression node)

Unary minus expressions are dumped like -expression.

Specified by:

arrive in interface NodeVisitor

Overrides:

arrive in class AbstractNodeVisitor

Parameters:

node - the node to dump

leave

public java.lang.Object leave(FieldAccessExpression node,
                              java.lang.Object[] results)

Field access expressions are dumped like target.fieldName.

Specified by:

leave in interface NodeVisitor

Overrides:

leave in class AbstractNodeVisitor

Parameters:

node - the node to dump

results - the results of walking the node's children

Returns:

the result of the delegation call

leave

public java.lang.Object leave(QueryTree node,
                              java.lang.Object[] results)

Query trees are dumped like orderingExpressions, filterExpression.

Specified by:

leave in interface NodeVisitor

Overrides:

leave in class AbstractNodeVisitor

Parameters:

node - the node to dump

results - the results of walking the node's children

Returns:

the result of the delegation call

walkNextChild

public boolean walkNextChild(AndExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A logical and expression is dumped like (leftExpression & rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(ConditionalAndExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A conditional and expression is dumped like (leftExpression && rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(ConditionalOrExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A logical or expression is dumped like (leftExpression || rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(DivideExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A divide expression is dumped like (leftExpression / rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(EqualsExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

An equals expression is dumped like (leftExpression == rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(GreaterThanEqualsExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A greater than equals expression is dumped like (leftExpression >= rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(GreaterThanExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A greater than expression is dumped like (leftExpression > rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(LessThanEqualsExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A less than equals expression is dumped like (leftExpression <= rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(LessThanExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A less than expression is dumped like (leftExpression < rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(MinusExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A minus expression is dumped like (leftExpression - rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(NotEqualsExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

Dumps a not equals expression. It is dumped like (leftExpression != rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(OrExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A logical or expression is dumped like (leftExpression | rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(QueryTree node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

Query trees are dumped like orderingExpressions, filterExpression.

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(PlusExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A plus expression is dumped like (leftExpression + rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true

walkNextChild

public boolean walkNextChild(TimesExpression node,
                             java.lang.Object resultOfPreviousChild,
                             int indexOfNextChild)

A times expression is dumped like (leftExpression * rightExpression).

Specified by:

walkNextChild in interface NodeVisitor

Overrides:

walkNextChild in class AbstractNodeVisitor

Parameters:

node - the parent node of the children currently dumped

resultOfPreviousChild - an array of null instances

indexOfNextChild - the index of the next child to be dumped

Returns:

true