org.springframework.integration.jpa.support.parametersource.ExpressionEvaluatingParameterSource.java Source code

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Here is the source code for org.springframework.integration.jpa.support.parametersource.ExpressionEvaluatingParameterSource.java

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/*
 * Copyright 2002-2012 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.integration.jpa.support.parametersource;

import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.expression.ExpressionException;
import org.springframework.integration.jpa.support.JpaParameter;
import org.springframework.integration.jpa.support.parametersource.ExpressionEvaluatingParameterSourceUtils.ParameterExpressionEvaluator;
import org.springframework.util.Assert;

/**
*
* @author Gunnar Hillert
* @since 2.2
*
*/
class ExpressionEvaluatingParameterSource implements PositionSupportingParameterSource {

    private static final Log logger = LogFactory.getLog(ExpressionEvaluatingParameterSource.class);

    private static final Object ERROR = new Object();

    private final Object input;

    private volatile Map<String, Object> values = new HashMap<String, Object>();

    private final Map<String, String> parameterExpressions;

    private final List<JpaParameter> parameters;

    private final ParameterExpressionEvaluator expressionEvaluator;

    ExpressionEvaluatingParameterSource(Object input, List<JpaParameter> parameters,
            ParameterExpressionEvaluator expressionEvaluator) {

        this.input = input;
        this.expressionEvaluator = expressionEvaluator;
        this.parameters = parameters;
        this.parameterExpressions = ExpressionEvaluatingParameterSourceUtils.convertExpressions(parameters);
        this.values.putAll(ExpressionEvaluatingParameterSourceUtils.convertStaticParameters(parameters));

    }

    public Object getValueByPosition(int position) {

        Assert.isTrue(position >= 0, "The position must be be non-negative.");

        if (position <= parameters.size()) {

            final JpaParameter parameter = parameters.get(position);

            if (parameter.getValue() != null) {
                return parameter.getValue();
            }

            if (parameter.getExpression() != null) {
                String expression = parameter.getExpression();

                if (input instanceof Collection<?>) {
                    expression = "#root.![" + expression + "]";
                }

                final Object value = this.expressionEvaluator.evaluateExpression(expression, input);
                //FIXME values.put(paramName, value);
                if (logger.isDebugEnabled()) {
                    logger.debug("Resolved expression " + expression + " to " + value);
                }
                return value;

            }

        }

        return null;

    }

    public Object getValue(String paramName) {
        if (values.containsKey(paramName)) {
            return values.get(paramName);
        }
        String expression = paramName;
        if (parameterExpressions.containsKey(expression)) {
            expression = parameterExpressions.get(expression);
        }
        if (input instanceof Collection<?>) {
            expression = "#root.![" + expression + "]";
        }
        final Object value = this.expressionEvaluator.evaluateExpression(expression, input);
        values.put(paramName, value);
        if (logger.isDebugEnabled()) {
            logger.debug("Resolved expression " + expression + " to " + value);
        }
        return value;
    }

    public boolean hasValue(String paramName) {
        try {
            final Object value = getValue(paramName);
            if (value == ERROR) {
                return false;
            }
        } catch (ExpressionException e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Could not evaluate expression", e);
            }
            values.put(paramName, ERROR);
            return false;
        }
        return true;
    }
}