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feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
//--------------------------------------------------------------------------
// Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// Neither the name of the Drew Davidson nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
// OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
// AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
// DAMAGE.
//--------------------------------------------------------------------------
package com.feilong.lib.ognl;
/**
* An Evaluation is and object that holds a node being evaluated
* and the source from which that node will take extract its
* value. It refers to child evaluations that occur as
* a result of the nodes' evaluation.
*/
public class Evaluation extends Object{
private SimpleNode node;
private Object source;
private boolean setOperation;
private Object result;
private Throwable exception;
private Evaluation parent;
private Evaluation next;
private Evaluation previous;
private Evaluation firstChild;
private Evaluation lastChild;
/**
* Constructs a new "get" Evaluation from the node and source given.
*
* @param node
* a SimpleNode for this Evaluation.
* @param source
* a source Object for this Evaluation.
*/
public Evaluation(SimpleNode node, Object source){
super();
this.node = node;
this.source = source;
}
/**
* Constructs a new Evaluation from the node and source given.
* If setOperation is true this Evaluation represents
* a "set" as opposed to a "get".
*
* @param node
* a SimpleNode for this Evaluation.
* @param source
* a source Object for this Evaluation.
* @param setOperation
* true to identify this Evaluation as a set operation, false to identify it as a get operation.
*/
public Evaluation(SimpleNode node, Object source, boolean setOperation){
this(node, source);
this.setOperation = setOperation;
}
/**
* Returns the SimpleNode for this Evaluation
*
* @return the SimpleNode for this Evaluation.
*/
public SimpleNode getNode(){
return node;
}
/**
* Sets the node of the evaluation. Normally applications do not need to
* set this. Notable exceptions to this rule are custom evaluators that
* choose between navigable objects (as in a multi-root evaluator where
* the navigable node is chosen at runtime).
*
* @param value
* the SimpleNode to set for this Evaluation.
*/
public void setNode(SimpleNode value){
node = value;
}
/**
* Returns the source object on which this Evaluation operated.
*
* @return the source Object operated upon by this Evaluation.
*/
public Object getSource(){
return source;
}
/**
* Sets the source of the evaluation. Normally applications do not need to
* set this. Notable exceptions to this rule are custom evaluators that
* choose between navigable objects (as in a multi-root evaluator where
* the navigable node is chosen at runtime).
*
* @param value
* the source Object to be set for this Evaluation.
*/
public void setSource(Object value){
source = value;
}
/**
* Returns true if this Evaluation represents a set operation.
*
* @return true if this Evaluation represents a set operation, false otherwise.
*/
public boolean isSetOperation(){
return setOperation;
}
/**
* Marks the Evaluation as a set operation if the value is true, else
* marks it as a get operation.
*
* @param value
* true to identify this Evaluation as a set operation, false to identify it as a get operation.
*/
public void setSetOperation(boolean value){
setOperation = value;
}
/**
* Returns the result of the Evaluation, or null if it was a set operation.
*
* @return the result of the Evaluation (for a get operation), or null (for a set operation).
*/
public Object getResult(){
return result;
}
/**
* Sets the result of the Evaluation. This method is normally only used
* interally and should not be set without knowledge of what you are doing.
*
* @param value
* the result Object for this Evaluation.
*/
public void setResult(Object value){
result = value;
}
/**
* Returns the exception that occurred as a result of evaluating the
* Evaluation, or null if no exception occurred.
*
* @return an exception if one occurred during evaluation, or null (no exception) otherwise.
*/
public Throwable getException(){
return exception;
}
/**
* Sets the exception that occurred as a result of evaluating the
* Evaluation. This method is normally only used interally and
* should not be set without knowledge of what you are doing.
*
* @param value
* the Throwable exception that occurred during the evaluation of this Evaluation.
*/
public void setException(Throwable value){
exception = value;
}
/**
* Returns the parent evaluation of this evaluation. If this returns
* null then it is is the root evaluation of a tree.
*
* @return the parent Evaluation of the current Evaluation, or null if no parent exists.
*/
public Evaluation getParent(){
return parent;
}
/**
* Returns the next sibling of this evaluation. Returns null if
* this is the last in a chain of evaluations.
*
* @return the next sibling Evaluation of the current Evaluation, or null if this is the last Evaluation in a chain.
*/
public Evaluation getNext(){
return next;
}
/**
* Returns the previous sibling of this evaluation. Returns null if
* this is the first in a chain of evaluations.
*
* @return the previous sibling Evaluation of the current Evaluation, or null if this is the first Evaluation in a chain.
*/
public Evaluation getPrevious(){
return previous;
}
/**
* Returns the first child of this evaluation. Returns null if
* there are no children.
*
* @return the first child Evaluation of the current Evaluation, or null if no children exist.
*/
public Evaluation getFirstChild(){
return firstChild;
}
/**
* Returns the last child of this evaluation. Returns null if
* there are no children.
*
* @return the last child Evaluation of the current Evaluation, or null if no children exist.
*/
public Evaluation getLastChild(){
return lastChild;
}
/**
* Gets the first descendent. In any Evaluation tree this will the
* Evaluation that was first executed.
*
* @return the first descendant Evaluation (first Evaluation executed in the tree).
*/
public Evaluation getFirstDescendant(){
if (firstChild != null){
return firstChild.getFirstDescendant();
}
return this;
}
/**
* Gets the last descendent. In any Evaluation tree this will the
* Evaluation that was most recently executing.
*
* @return the last descendant Evaluation (most recent Evaluation executed in the tree).
*/
public Evaluation getLastDescendant(){
if (lastChild != null){
return lastChild.getLastDescendant();
}
return this;
}
/**
* Adds a child to the list of children of this evaluation. The
* parent of the child is set to the receiver and the children
* references are modified in the receiver to reflect the new child.
* The lastChild of the receiver is set to the child, and the
* firstChild is set also if child is the first (or only) child.
*
* @param child
* an Evaluation to add as a child to the current Evaluation.
*/
public void addChild(Evaluation child){
if (firstChild == null){
firstChild = lastChild = child;
}else{
if (firstChild == lastChild){
firstChild.next = child;
lastChild = child;
lastChild.previous = firstChild;
}else{
child.previous = lastChild;
lastChild.next = child;
lastChild = child;
}
}
child.parent = this;
}
/**
* Reinitializes this Evaluation to the parameters specified.
*
* @param node
* a SimpleNode for this Evaluation.
* @param source
* a source Object for this Evaluation.
* @param setOperation
* true to identify this Evaluation as a set operation, false to identify it as a get operation.
*/
public void init(SimpleNode node,Object source,boolean setOperation){
this.node = node;
this.source = source;
this.setOperation = setOperation;
result = null;
exception = null;
parent = null;
next = null;
previous = null;
firstChild = null;
lastChild = null;
}
/**
* Resets this Evaluation to the initial state.
*/
public void reset(){
init(null, null, false);
}
/**
* Produces a String value for the Evaluation. If compact is
* true then a more compact form of the description only including
* the node type and unique identifier is shown, else a full
* description including source and result are shown. If showChildren
* is true the child evaluations are printed using the depth string
* given as a prefix.
*
* @param compact
* true to generate a compact form of the description for this Evaluation, false for a full form.
* @param showChildren
* true to generate descriptions for child Evaluation elements of this Evaluation.
* @param depth
* prefix String to use in front of child Evaluation description output - used when showChildren is true.
* @return the description of this Evaluation as a String.
*/
public String toString(boolean compact,boolean showChildren,String depth){
String stringResult;
if (compact){
stringResult = depth + "<" + node.getClass().getName() + " " + System.identityHashCode(this) + ">";
}else{
String ss = (source != null) ? source.getClass().getName() : "null",
rs = (result != null) ? result.getClass().getName() : "null";
stringResult = depth + "<" + node.getClass().getName() + ": [" + (setOperation ? "set" : "get") + "] source = " + ss
+ ", result = " + result + " [" + rs + "]>";
}
if (showChildren){
Evaluation child = firstChild;
stringResult += "\n";
while (child != null){
stringResult += child.toString(compact, depth + " ");
child = child.next;
}
}
return stringResult;
}
/**
* Produces a String value for the Evaluation. If compact is
* true then a more compact form of the description only including
* the node type and unique identifier is shown, else a full
* description including source and result are shown. Child
* evaluations are printed using the depth string given as a prefix.
*
* @param compact
* true to generate a compact form of the description for this Evaluation, false for a full form.
* @param depth
* prefix String to use in front of child Evaluation description output - used when showChildren is true.
* @return the description of this Evaluation as a String.
*/
public String toString(boolean compact,String depth){
return toString(compact, true, depth);
}
/**
* Returns a String description of the Evaluation.
*
* @return the description of this Evaluation as a String.
*/
@Override
public String toString(){
return toString(false, "");
}
}