com.redhat.lightblue.query.RelationalExpression.java Source code

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Here is the source code for com.redhat.lightblue.query.RelationalExpression.java

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/*
 Copyright 2013 Red Hat, Inc. and/or its affiliates.
    
 This file is part of lightblue.
    
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
    
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
    
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.redhat.lightblue.query;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.redhat.lightblue.util.Error;

/**
 * Base class for all relational expression
 */
public abstract class RelationalExpression extends ComparisonExpression {
    private static final long serialVersionUID = 1L;

    /**
     * Parses a relational expression using the given object node
     */
    public static RelationalExpression fromJson(ObjectNode node) {
        JsonNode x = node.get("regex");
        if (x != null) {
            return RegexMatchExpression.fromJson(node);
        } else {
            x = node.get("op");
            if (x != null) {
                String op = x.asText();
                if (BinaryComparisonOperator.fromString(op) != null) {
                    return BinaryRelationalExpression.fromJson(node);
                } else if (NaryRelationalOperator.fromString(op) != null) {
                    return NaryRelationalExpression.fromJson(node);
                }
            }
        }
        throw Error.get(QueryConstants.ERR_INVALID_COMPARISON_EXPRESSION, node.toString());
    }
}