org.springframework.binding.expression.ExpressionVariable Maven / Gradle / Ivy
/*
* Copyright 2004-2008 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;
import org.springframework.util.Assert;
/**
* An expression variable.
* @author Keith Donald
*/
public class ExpressionVariable {
private String name;
private String valueExpression;
private ParserContext parserContext;
/**
* Creates a new expression variable.
* @param name the name of the variable, acting as an convenient alias (required)
* @param valueExpression the value expression (required)
*/
public ExpressionVariable(String name, String valueExpression) {
init(name, valueExpression, null);
}
/**
* Creates a new expression variable with a populated parser context.
* @param name the name of the variable, acting as an convenient alias (required)
* @param valueExpression the value expression (required)
* @param parserContext the parser context to use to parse the value expression (optional)
*/
public ExpressionVariable(String name, String valueExpression, ParserContext parserContext) {
init(name, valueExpression, parserContext);
}
/**
* Returns the variable name.
* @return the variable name
*/
public String getName() {
return name;
}
/**
* Returns the expression that will be evaluated when the variable is referenced by its name in another expression.
* @return the expression value.
*/
public String getValueExpression() {
return valueExpression;
}
/**
* Returns the parser context to use to parse the variable's value expression.
* @return the value expression parser context
*/
public ParserContext getParserContext() {
return parserContext;
}
public boolean equals(Object o) {
if (!(o instanceof ExpressionVariable)) {
return false;
}
ExpressionVariable var = (ExpressionVariable) o;
return name.equals(var.name);
}
public int hashCode() {
return name.hashCode();
}
public String toString() {
return "[Expression Variable '" + name + "']";
}
private void init(String name, String valueExpression, ParserContext parserContext) {
Assert.hasText(name, "The expression variable must be named");
Assert.hasText(valueExpression, "The expression variable's value expression is required");
this.name = name;
this.valueExpression = valueExpression;
this.parserContext = parserContext;
}
}