SimpleStorageNameUtils.java

/*
 * Copyright 2013-2014 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.cloud.aws.core.io.s3;

import org.springframework.util.Assert;

/**
 * Utility class that provides utility method to work with s3 storage resources
 *
 * @author Agim Emruli
 * @author Alain Sahli
 * @since 1.0
 */
final class SimpleStorageNameUtils {

    private static final String S3_PROTOCOL_PREFIX = "s3://";
    private static final String PATH_DELIMITER = "/";
    private static final String VERSION_DELIMITER = "^";

    private SimpleStorageNameUtils() {
        // Avoid instantiation
    }

    static boolean isSimpleStorageResource(String location) {
        Assert.notNull(location, "Location must not be null");
        return location.toLowerCase().startsWith(S3_PROTOCOL_PREFIX);
    }

    static String getBucketNameFromLocation(String location) {
        Assert.notNull(location, "Location must not be null");
        if (!isSimpleStorageResource(location)) {
            throw new IllegalArgumentException("The location :'" + location + "' is not a valid S3 location");
        }
        int bucketEndIndex = location.indexOf(PATH_DELIMITER, S3_PROTOCOL_PREFIX.length());
        if (bucketEndIndex == -1 || bucketEndIndex == S3_PROTOCOL_PREFIX.length()) {
            throw new IllegalArgumentException("The location :'" + location + "' does not contain a valid bucket name");
        }
        return location.substring(S3_PROTOCOL_PREFIX.length(), bucketEndIndex);
    }

    static String getObjectNameFromLocation(String location) {
        Assert.notNull(location, "Location must not be null");
        if (!isSimpleStorageResource(location)) {
            throw new IllegalArgumentException("The location :'" + location + "' is not a valid S3 location");
        }
        int bucketEndIndex = location.indexOf(PATH_DELIMITER, S3_PROTOCOL_PREFIX.length());
        if (bucketEndIndex == -1 || bucketEndIndex == S3_PROTOCOL_PREFIX.length()) {
            throw new IllegalArgumentException("The location :'" + location + "' does not contain a valid bucket name");
        }

        if (location.contains(VERSION_DELIMITER)) {
            return getObjectNameFromLocation(location.substring(0, location.indexOf(VERSION_DELIMITER)));
        }

        if (location.endsWith(PATH_DELIMITER)) {
            return location.substring(++bucketEndIndex, location.length() - 1);
        }

        return location.substring(++bucketEndIndex, location.length());
    }

    static String getVersionIdFromLocation(String location) {
        Assert.notNull(location, "Location must not be null");
        if (!isSimpleStorageResource(location)) {
            throw new IllegalArgumentException("The location :'" + location + "' is not a valid S3 location");
        }
        int objectNameEndIndex = location.indexOf(VERSION_DELIMITER, S3_PROTOCOL_PREFIX.length());
        if (objectNameEndIndex == -1 || location.endsWith(VERSION_DELIMITER)) {
            return null;
        }

        if (objectNameEndIndex == S3_PROTOCOL_PREFIX.length()) {
            throw new IllegalArgumentException("The location :'" + location + "' does not contain a valid bucket name");
        }

        return location.substring(++objectNameEndIndex, location.length());
    }

    static String getLocationForBucketAndObject(String bucketName, String objectName) {
        Assert.notNull(bucketName, "Bucket name must not be null");
        Assert.notNull(objectName, "ObjectName name must not be null");
        StringBuilder location = new StringBuilder(S3_PROTOCOL_PREFIX.length() + bucketName.length() +
                PATH_DELIMITER.length() + objectName.length());
        location.append(S3_PROTOCOL_PREFIX);
        location.append(bucketName);
        location.append(PATH_DELIMITER);
        location.append(objectName);
        return location.toString();
    }

    static String getLocationForBucketAndObjectAndVersionId(String bucketName, String objectName, String versionId) {
        String location = getLocationForBucketAndObject(bucketName, objectName);
        return new StringBuffer(location).append(VERSION_DELIMITER).append(versionId).toString();
    }

    static String stripProtocol(String location) {
        Assert.notNull(location, "Location must not be null");
        if (!isSimpleStorageResource(location)) {
            throw new IllegalArgumentException("The location :'" + location + "' is not a valid S3 location");
        }
        return location.substring(S3_PROTOCOL_PREFIX.length());
    }

}