/*
* Copyright 2004-2012 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.binding.expression.support;
import org.springframework.binding.expression.EvaluationException;
import org.springframework.binding.expression.Expression;
import org.springframework.util.Assert;
public class LiteralExpression implements Expression {
/**
* The string literal.
*/
private String literal;
/**
* Create a literal expression for the given literal.
* @param literal the literal
*/
public LiteralExpression(String literal) {
Assert.notNull(literal, "The literal is required");
this.literal = literal;
}
public int hashCode() {
return literal.hashCode();
}
public boolean equals(Object o) {
if (!(o instanceof LiteralExpression)) {
return false;
}
LiteralExpression other = (LiteralExpression) o;
return literal.equals(other.literal);
}
public Object getValue(Object context) throws EvaluationException {
return literal;
}
public void setValue(Object context, Object value) throws EvaluationException {
throw new UnsupportedOperationException(
"Cannot set a literal expression value. Are you attempting to set a property expression? "
+ "If so, should the expression string be enclosed in eval delimiters?");
}
public Class<?> getValueType(Object context) {
return String.class;
}
public String getExpressionString() {
return null;
}
public String toString() {
return literal;
}
}