/*
* Copyright 2002-2009 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.expression.spel.ast;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.TypedValue;
import org.springframework.expression.spel.ExpressionState;
import org.springframework.expression.spel.SpelEvaluationException;
/**
* Represents a DOT separated expression sequence, such as 'property1.property2.methodOne()'
*
* @author Andy Clement
* @since 3.0
*/
public class CompoundExpression extends SpelNodeImpl {
public CompoundExpression(int pos,SpelNodeImpl... expressionComponents) {
super(pos,expressionComponents);
if (expressionComponents.length<2) {
throw new IllegalStateException("Dont build compound expression less than one entry: "+expressionComponents.length);
}
}
/**
* Evalutes a compound expression. This involves evaluating each piece in turn and the return value from each piece
* is the active context object for the subsequent piece.
* @param state the state in which the expression is being evaluated
* @return the final value from the last piece of the compound expression
*/
@Override
public TypedValue getValueInternal(ExpressionState state) throws EvaluationException {
TypedValue result = null;
SpelNodeImpl nextNode = null;
try {
nextNode = children[0];
result = nextNode.getValueInternal(state);
for (int i = 1; i < getChildCount(); i++) {
try {
state.pushActiveContextObject(result);
nextNode = children[i];
result = nextNode.getValueInternal(state);
} finally {
state.popActiveContextObject();
}
}
} catch (SpelEvaluationException ee) {
// Correct the position for the error before rethrowing
ee.setPosition(nextNode.getStartPosition());
throw ee;
}
return result;
}
@Override
public void setValue(ExpressionState state, Object value) throws EvaluationException {
if (getChildCount() == 1) {
getChild(0).setValue(state, value);
return;
}
TypedValue ctx = children[0].getValueInternal(state);
for (int i = 1; i < getChildCount() - 1; i++) {
try {
state.pushActiveContextObject(ctx);
ctx = children[i].getValueInternal(state);
} finally {
state.popActiveContextObject();
}
}
try {
state.pushActiveContextObject(ctx);
getChild(getChildCount() - 1).setValue(state, value);
} finally {
state.popActiveContextObject();
}
}
@Override
public boolean isWritable(ExpressionState state) throws EvaluationException {
if (getChildCount() == 1) {
return getChild(0).isWritable(state);
}
TypedValue ctx = children[0].getValueInternal(state);
for (int i = 1; i < getChildCount() - 1; i++) {
try {
state.pushActiveContextObject(ctx);
ctx = children[i].getValueInternal(state);
} finally {
state.popActiveContextObject();
}
}
try {
state.pushActiveContextObject(ctx);
return getChild(getChildCount() - 1).isWritable(state);
} finally {
state.popActiveContextObject();
}
}
@Override
public String toStringAST() {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < getChildCount(); i++) {
if (i>0) { sb.append("."); }
sb.append(getChild(i).toStringAST());
}
return sb.toString();
}
}
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