com.brandwatch.robots.MissingPrefixFixingFunction Maven / Gradle / Ivy

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Support for Robots Exclusion Protocol, including parsing and matching against robot.txt directives.

There is a newer version: 1.2.1

package com.brandwatch.robots;

/*
 * #%L
 * Robots (core)
 * %%
 * Copyright (C) 2014 - 2015 Brandwatch
 * %%
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 
 * 3. Neither the name of the Brandwatch nor the names of its contributors
 *    may be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * #L%
 */

import com.google.common.base.Function;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import static com.google.common.base.Preconditions.checkNotNull;

class MissingPrefixFixingFunction implements Function {

    @Nullable
    @Override
    public String apply(@Nonnull String input) {
        checkNotNull(input, "input is null");
        if (!input.isEmpty()) {
            final char c = input.charAt(0);
            if (c != '/' && c != '*' && c != '^') {
                return '/' + input;
            }
        }
        return input;
    }
}