org.springframework.data.mapping.model.DefaultSpELExpressionEvaluator.java Source code

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Here is the source code for org.springframework.data.mapping.model.DefaultSpELExpressionEvaluator.java

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/*
 * Copyright 2011-2019 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 org.springframework.data.mapping.model;

import lombok.NonNull;
import lombok.RequiredArgsConstructor;

import org.springframework.data.mapping.PreferredConstructor.Parameter;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.Expression;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.lang.Nullable;

/**
 * {@link ParameterValueProvider} implementation that evaluates the {@link Parameter}s key against
 * {@link SpelExpressionParser} and {@link EvaluationContext}.
 *
 * @author Oliver Gierke
 */
@RequiredArgsConstructor
public class DefaultSpELExpressionEvaluator implements SpELExpressionEvaluator {

    private final @NonNull Object source;
    private final @NonNull SpELContext factory;

    /*
     * (non-Javadoc)
     * @see org.springframework.data.mapping.model.SpELExpressionEvaluator#evaluate(java.lang.String)
     */
    @Nullable
    @SuppressWarnings("unchecked")
    public <T> T evaluate(String expression) {

        Expression parseExpression = factory.getParser().parseExpression(expression);
        return (T) parseExpression.getValue(factory.getEvaluationContext(source));
    }
}