com.livk.commons.expression.jexl3.JexlExpressionResolver Maven / Gradle / Ivy
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/*
* Copyright 2021-2024 spring-boot-extension 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
*
* https://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 com.livk.commons.expression.jexl3;
import com.livk.commons.expression.Context;
import com.livk.commons.expression.ConverterExpressionResolver;
import lombok.RequiredArgsConstructor;
import org.apache.commons.jexl3.JexlContext;
import org.apache.commons.jexl3.JexlEngine;
import org.apache.commons.jexl3.JexlExpression;
import org.apache.commons.jexl3.MapContext;
import org.apache.commons.jexl3.internal.Engine;
import java.util.Optional;
/**
* 使用Apache Commons Jexl3实现的表达式解析器
*
* @author livk
*/
@RequiredArgsConstructor
public class JexlExpressionResolver extends ConverterExpressionResolver {
private static final JexlEngine DEFAULT_ENGINE = new Engine();
private final JexlEngine engine;
/**
* Instantiates a new Jexl expression resolver.
*/
public JexlExpressionResolver() {
this(Optional.ofNullable(JexlEngine.getThreadEngine()).orElse(DEFAULT_ENGINE));
}
@Override
protected JexlExpression compile(String value) {
return engine.createExpression(value);
}
@Override
protected JexlContext transform(Context context) {
return new MapContext(context);
}
@Override
protected T calculate(JexlExpression expression, JexlContext context, Class returnType) {
return returnType.cast(expression.evaluate(context));
}
}