Package org.apache.cayenne.exp.parser
Class SimpleNode
java.lang.Object
org.apache.cayenne.exp.Expression
org.apache.cayenne.exp.parser.SimpleNode
- All Implemented Interfaces:
Serializable,Node,XMLSerializable
- Direct Known Subclasses:
AggregateConditionNode,ASTAsterisk,ASTFullObject,ASTList,ASTNegate,ASTPath,ASTScalar,ConditionNode,EvaluatedNode
public abstract class SimpleNode extends Expression implements Node
Superclass of AST* expressions that implements Node interface defined by JavaCC framework.
Some parts of the parser are based on OGNL parser, copyright (c) 2002, Drew Davidson and Luke Blanshard.
- Since:
- 1.1
- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description protected Node[]childrenprotected intidprotected NodeparentFields inherited from class org.apache.cayenne.exp.Expression
ADD, AND, ASTERISK, BETWEEN, BITWISE_AND, BITWISE_LEFT_SHIFT, BITWISE_NOT, BITWISE_OR, BITWISE_RIGHT_SHIFT, BITWISE_XOR, DB_PATH, DIVIDE, EQUAL_TO, FALSE, FULL_OBJECT, FUNCTION_CALL, GREATER_THAN, GREATER_THAN_EQUAL_TO, IN, LESS_THAN, LESS_THAN_EQUAL_TO, LIKE, LIKE_IGNORE_CASE, LIST, MULTIPLY, NEGATIVE, NOT, NOT_BETWEEN, NOT_EQUAL_TO, NOT_IN, NOT_LIKE, NOT_LIKE_IGNORE_CASE, OBJ_PATH, OR, PRUNED_NODE, SUBTRACT, TRUE, type -
Constructor Summary
Constructors Modifier Constructor Description protectedSimpleNode(int i) -
Method Summary
Modifier and Type Method Description voidappendAsEJBQL(Appendable out, String rootId)Stores a String representation of Expression as EJBQL using a provided Appendable.voidappendAsEJBQL(List<Object> parameterAccumulator, Appendable out, String rootId)Stores a String representation of Expression as EJBQL using a provided PrintWriter.protected static voidappendAsEscapedString(Appendable out, String source)Utility method that prints a string to the provided Appendable, escaping special characters.voidappendAsString(Appendable out)Appends own content as a String to the provided Appendable.protected voidappendChildrenAsEJBQL(List<Object> parameterAccumulator, Appendable out, String rootId)Encodes child of this node with specified index to EJBQLprotected static voidappendScalarAsString(Appendable out, Object scalar, char quoteChar)Utility method that encodes an object that is not an expression Node to String.protected voidconnectChildren()Sets the parent to this for all children.protected static voidencodeScalarAsEJBQL(List<Object> parameterAccumulator, Appendable out, Object scalar)This is a utility method that can represent the supplied scalar as either an EJBQL literal into the suppliedPrintWriteror is able to add the scalar to the parameters and to instead write a positional parameter to the EJBQL written to thePrintWriter.Objectevaluate(Object o)Calculates expression value with object as a context for path expressions.protected ObjectevaluateChild(int index, Object o)protected abstract ObjectevaluateNode(Object o)Evaluates itself with object, pushing result on the stack.StringexpName()Implemented for backwards compatibility with exp package.protected voidflattenTree()Flattens the tree under this node by eliminating any children that are of the same class as this node and copying their children to this node.protected StringgetEJBQLExpressionOperator(int index)Returns operator for EJBQL statements, which can differ for Cayenne expression operatorprotected abstract StringgetExpressionOperator(int index)ObjectgetOperand(int index)Returns a value of operand atindex.intgetOperandCount()Returns a count of operands of this expression.Map<String,String>getPathAliases()Always returns empty map.voidjjtAddChild(Node n, int i)This method tells the node to add its argument to the node's list of children.voidjjtClose()Called after all the child nodes have been added.NodejjtGetChild(int i)This method returns a child node.intjjtGetNumChildren()Return the number of children the node has.NodejjtGetParent()voidjjtOpen()Called after the node has been made the current node.voidjjtSetParent(Node n)This pair of methods are used to inform the node of its parent.ExpressionnotExp()Returns a logical NOT of current expression.protected booleanpruneNodeForPrunedChild(Object prunedChild)Returns true if this node should be pruned from expression tree in the event a child is removed.voidsetOperand(int index, Object value)Sets a value of operand atindex.protected ObjectunwrapChild(Node child)protected NodewrapChild(Object child)Methods inherited from class org.apache.cayenne.exp.Expression
andExp, andExp, deepCopy, encodeAsXML, equals, filter, filterObjects, first, getType, hashCode, joinExp, joinExp, match, orExp, orExp, params, params, paramsArray, setType, shallowCopy, toEJBQL, toEJBQL, toString, transform, transformExpression, traverse, traverse
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Field Details
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parent
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children
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id
protected int id
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Constructor Details
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SimpleNode
protected SimpleNode(int i)
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Method Details
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encodeScalarAsEJBQL
protected static void encodeScalarAsEJBQL(List<Object> parameterAccumulator, Appendable out, Object scalar) throws IOExceptionThis is a utility method that can represent the supplied scalar as either an EJBQL literal into the supplied
PrintWriteror is able to add the scalar to the parameters and to instead write a positional parameter to the EJBQL written to thePrintWriter. If the parameters are null and the scalar object is not able to be represented as an EJBQL literal then the method will throw a runtime exception to indicate that it has failed to produce valid EJBQL.- Throws:
IOException
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appendScalarAsString
protected static void appendScalarAsString(Appendable out, Object scalar, char quoteChar) throws IOExceptionUtility method that encodes an object that is not an expression Node to String.- Throws:
IOException
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appendAsEscapedString
Utility method that prints a string to the provided Appendable, escaping special characters.- Throws:
IOException
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getPathAliases
Always returns empty map.- Specified by:
getPathAliasesin classExpression- Since:
- 3.0
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getExpressionOperator
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getEJBQLExpressionOperator
Returns operator for EJBQL statements, which can differ for Cayenne expression operator -
pruneNodeForPrunedChild
Description copied from class:ExpressionReturns true if this node should be pruned from expression tree in the event a child is removed.- Specified by:
pruneNodeForPrunedChildin classExpression
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expName
Implemented for backwards compatibility with exp package.- Overrides:
expNamein classExpression
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flattenTree
protected void flattenTree()Flattens the tree under this node by eliminating any children that are of the same class as this node and copying their children to this node.- Specified by:
flattenTreein classExpression
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appendAsString
Description copied from class:ExpressionAppends own content as a String to the provided Appendable.- Specified by:
appendAsStringin classExpression- Throws:
IOException- Since:
- 4.0
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getOperand
Description copied from class:ExpressionReturns a value of operand atindex. Operand indexing starts at 0.- Specified by:
getOperandin classExpression
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wrapChild
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unwrapChild
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getOperandCount
public int getOperandCount()Description copied from class:ExpressionReturns a count of operands of this expression. In real life there are unary (count == 1), binary (count == 2) and ternary (count == 3) expressions.- Specified by:
getOperandCountin classExpression
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setOperand
Description copied from class:ExpressionSets a value of operand atindex. Operand indexing starts at 0.- Specified by:
setOperandin classExpression
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jjtOpen
public void jjtOpen()Description copied from interface:NodeCalled after the node has been made the current node. It indicates that child nodes can now be added to it. -
jjtClose
public void jjtClose()Description copied from interface:NodeCalled after all the child nodes have been added. -
jjtSetParent
Description copied from interface:NodeThis pair of methods are used to inform the node of its parent.- Specified by:
jjtSetParentin interfaceNode
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jjtGetParent
- Specified by:
jjtGetParentin interfaceNode
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jjtAddChild
Description copied from interface:NodeThis method tells the node to add its argument to the node's list of children.- Specified by:
jjtAddChildin interfaceNode
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jjtGetChild
Description copied from interface:NodeThis method returns a child node. The children are numbered from zero, left to right.- Specified by:
jjtGetChildin interfaceNode
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jjtGetNumChildren
public final int jjtGetNumChildren()Description copied from interface:NodeReturn the number of children the node has.- Specified by:
jjtGetNumChildrenin interfaceNode
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evaluateNode
Evaluates itself with object, pushing result on the stack.- Throws:
Exception
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connectChildren
protected void connectChildren()Sets the parent to this for all children.- Since:
- 3.0
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evaluateChild
- Throws:
Exception
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notExp
Description copied from class:ExpressionReturns a logical NOT of current expression.- Specified by:
notExpin classExpression
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evaluate
Description copied from class:ExpressionCalculates expression value with object as a context for path expressions.- Specified by:
evaluatein classExpression
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appendAsEJBQL
Description copied from class:ExpressionStores a String representation of Expression as EJBQL using a provided Appendable. DB path expressions produce non-standard EJBQL path expressions.- Overrides:
appendAsEJBQLin classExpression- Throws:
IOException- Since:
- 4.0
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appendAsEJBQL
public void appendAsEJBQL(List<Object> parameterAccumulator, Appendable out, String rootId) throws IOExceptionDescription copied from class:ExpressionStores a String representation of Expression as EJBQL using a provided PrintWriter. DB path expressions produce non-standard EJBQL path expressions. If the parameterAccumulator is supplied then as the EJBQL is output, it may load parameters into this list. In this case, the EJBQL output will contain reference to positional parameters. If no parameterAccumulator is supplied and a scalar type is encountered for which there is no EJBQL literal representation (such as dates) then this method will throw a runtime exception to indicate that it was not possible to generate a string-only representation of the Expression in EJBQL.- Specified by:
appendAsEJBQLin classExpression- Throws:
IOException- Since:
- 4.0
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appendChildrenAsEJBQL
protected void appendChildrenAsEJBQL(List<Object> parameterAccumulator, Appendable out, String rootId) throws IOExceptionEncodes child of this node with specified index to EJBQL- Throws:
IOException
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