/*
* Copyright 2002-2010 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.integration.expression;
import java.util.Locale;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.core.convert.TypeDescriptor;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.Expression;
import org.springframework.util.Assert;
/**
* An implementation of {@link Expression} that delegates to an {@link ExpressionSource}
* for resolving the actual Expression instance per-invocation at runtime.
*
* @author Mark Fisher
* @since 2.0
*/
public class DynamicExpression implements Expression {
private final String key;
private final ExpressionSource expressionSource;
public DynamicExpression(String key, ExpressionSource expressionSource) {
Assert.notNull(key, "key must not be null");
Assert.notNull(expressionSource, "expressionSource must not be null");
this.key = key;
this.expressionSource = expressionSource;
}
public Object getValue() throws EvaluationException {
return this.resolveExpression().getValue();
}
public Object getValue(Object rootObject) throws EvaluationException {
return this.resolveExpression().getValue(rootObject);
}
public <T> T getValue(Class<T> desiredResultType) throws EvaluationException {
return this.resolveExpression().getValue(desiredResultType);
}
public <T> T getValue(Object rootObject, Class<T> desiredResultType) throws EvaluationException {
return this.resolveExpression().getValue(rootObject, desiredResultType);
}
public Object getValue(EvaluationContext context) throws EvaluationException {
return this.resolveExpression().getValue(context);
}
public Object getValue(EvaluationContext context, Object rootObject) throws EvaluationException {
return this.resolveExpression().getValue(context, rootObject);
}
public <T> T getValue(EvaluationContext context, Class<T> desiredResultType) throws EvaluationException {
return this.resolveExpression().getValue(context, desiredResultType);
}
public <T> T getValue(EvaluationContext context, Object rootObject, Class<T> desiredResultType) throws EvaluationException {
return this.resolveExpression().getValue(context, rootObject, desiredResultType);
}
public Class<?> getValueType() throws EvaluationException {
return this.resolveExpression().getValueType();
}
public Class<?> getValueType(Object rootObject) throws EvaluationException {
return this.resolveExpression().getValueType(rootObject);
}
public Class<?> getValueType(EvaluationContext context) throws EvaluationException {
return this.resolveExpression().getValueType(context);
}
public Class<?> getValueType(EvaluationContext context, Object rootObject) throws EvaluationException {
return this.resolveExpression().getValueType(context, rootObject);
}
public TypeDescriptor getValueTypeDescriptor() throws EvaluationException {
return this.resolveExpression().getValueTypeDescriptor();
}
public TypeDescriptor getValueTypeDescriptor(Object rootObject) throws EvaluationException {
return this.resolveExpression().getValueTypeDescriptor(rootObject);
}
public TypeDescriptor getValueTypeDescriptor(EvaluationContext context) throws EvaluationException {
return this.resolveExpression().getValueTypeDescriptor(context);
}
public TypeDescriptor getValueTypeDescriptor(EvaluationContext context, Object rootObject) throws EvaluationException {
return this.resolveExpression().getValueTypeDescriptor(context, rootObject);
}
public boolean isWritable(EvaluationContext context) throws EvaluationException {
return this.resolveExpression().isWritable(context);
}
public boolean isWritable(EvaluationContext context, Object rootObject) throws EvaluationException {
return this.resolveExpression().isWritable(context, rootObject);
}
public boolean isWritable(Object rootObject) throws EvaluationException {
return this.resolveExpression().isWritable(rootObject);
}
public void setValue(EvaluationContext context, Object value) throws EvaluationException {
this.resolveExpression().setValue(context, value);
}
public void setValue(Object rootObject, Object value) throws EvaluationException {
this.resolveExpression().setValue(rootObject, value);
}
public void setValue(EvaluationContext context, Object rootObject, Object value) throws EvaluationException {
this.resolveExpression().setValue(context, rootObject, value);
}
public String getExpressionString() {
return this.resolveExpression().getExpressionString();
}
private Expression resolveExpression() {
Locale locale = LocaleContextHolder.getLocale();
Expression expression = this.expressionSource.getExpression(this.key, locale);
Assert.state(expression != null, "Unable to resolve Expression with key '" + this.key + "'");
return expression;
}
}