com.stackframe.collect.RangeUtilities.java Source code

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Here is the source code for com.stackframe.collect.RangeUtilities.java

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/*
 * Copyright 2013 StackFrame, LLC
 *
 * This is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3
 * as published by the Free Software Foundation.
 *
 * You should have received a copy of the GNU General Public License
 * along with this file.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.stackframe.collect;

import com.google.common.collect.BoundType;
import com.google.common.collect.Range;
import static com.stackframe.sql.SQLUtilities.convert;
import java.util.Date;

/**
 * Useful functions for dealing with Range objects.
 *
 * @author Gene McCulley
 */
public class RangeUtilities {

    private RangeUtilities() {
        // inhibit construction of utility class
    }

    /**
     * Determine if a value is contained in any supplied Ranges.
     *
     * @param <C> the class that Range is constrained to
     * @param ranges the ranges to check
     * @param value the value to check for
     * @return true if value is contained in any of the ranges
     */
    public static <C extends Comparable> boolean contains(Iterable<Range<C>> ranges, C value) {
        for (Range<C> r : ranges) {
            if (r.contains(value)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Build an expression suitable for passing to JDBC as part of an SQL query from a date range.
     *
     * @param column the name of the column
     * @param dateRange the Range
     * @return a String containing the expression
     */
    public static String toSQL(String column, Range<Date> dateRange) {
        StringBuilder buf = new StringBuilder();
        if (dateRange.hasLowerBound()) {
            BoundType lowerBound = dateRange.lowerBoundType();
            String operator;
            switch (lowerBound) {
            case CLOSED:
                operator = ">=";
                break;
            case OPEN:
                operator = ">";
                break;
            default:
                throw new AssertionError("unexpected bound type " + lowerBound);
            }

            Date lowerEndpoint = dateRange.lowerEndpoint();
            java.sql.Date lowerDate = convert(lowerEndpoint);
            buf.append(String.format("%s %s '%s'", column, operator, lowerDate.toString()));
            if (dateRange.hasUpperBound()) {
                buf.append(" AND ");
            }
        }

        if (dateRange.hasUpperBound()) {
            BoundType upperBound = dateRange.upperBoundType();
            String operator;
            switch (upperBound) {
            case CLOSED:
                operator = "<=";
                break;
            case OPEN:
                operator = "<";
                break;
            default:
                throw new AssertionError("unexpected bound type " + upperBound);
            }

            Date upperEndpoint = dateRange.upperEndpoint();
            java.sql.Date upperDate = convert(upperEndpoint);
            buf.append(String.format("%s %s '%s'", column, operator, upperDate.toString()));
        }

        return buf.toString();
    }
}