model.data.location.FileAccessFactory.java Source code

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Here is the source code for model.data.location.FileAccessFactory.java

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/**
 * Copyright 2016, RadiantBlue Technologies, Inc.
 * 
 * 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 model.data.location;

import java.io.InputStream;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.amazonaws.AmazonClientException;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.AmazonS3EncryptionClient;
import com.amazonaws.services.s3.model.CryptoConfiguration;
import com.amazonaws.services.s3.model.KMSEncryptionMaterialsProvider;
import com.amazonaws.services.s3.model.S3Object;
import com.fasterxml.jackson.annotation.JsonIgnore;

import exception.InvalidInputException;

/**
 * Factory class that helps with the obtaining of Files represented by FileLocation interfaces; such as S3 files or
 * folder shares.
 * 
 * @author Patrick.Doody, Sonny.Saniev
 * 
 */
public class FileAccessFactory {
    private String s3ak = "";
    private String s3pk = "";
    private String s3ek = "";

    private static final Logger LOGGER = LoggerFactory.getLogger(FileAccessFactory.class);

    private static final String PROTOCOL_PREFIX = "https://";

    public FileAccessFactory() {
        // Empty constructor required by Jackson
    }

    public FileAccessFactory(String s3AccessKey, String s3PrivateKey, String s3EncryptKey) {
        this.s3ak = s3AccessKey;
        this.s3pk = s3PrivateKey;
        this.s3ek = s3EncryptKey;
    }

    public FileAccessFactory(String s3AccessKey, String s3PrivateKey) {
        this.s3ak = s3AccessKey;
        this.s3pk = s3PrivateKey;
        this.s3ek = null;
    }

    /**
     * Sets the AWS Credentials, required for pulling S3 files. If encryption is required, then the key should be
     * specified. If encryption is not required, then null should be specified as this value.
     * 
     * @param accessKey
     *            Access key
     * @param privateKey
     *            Private key
     * @param s3EncryptKey
     *            The encryption key. If specified, then encryption will be used. Set to null if not desired.
     */
    public void setS3Credentials(String s3AccessKey, String s3PrivateKey, String s3EncryptKey) {
        this.s3ak = s3AccessKey;
        this.s3pk = s3PrivateKey;
        this.s3ek = s3EncryptKey;
    }

    /**
     * Returns the InputStream for a file represented by an object implementing the FileLocation interface
     * 
     * @param fileLocation
     *            The file location
     * @return The File stream
     */
    public InputStream getFile(FileLocation fileLocation) throws AmazonClientException, InvalidInputException {
        if (fileLocation instanceof FolderShare) {
            return ((FolderShare) fileLocation).getFile();
        } else if (fileLocation instanceof S3FileStore) {
            try {
                return getS3File(fileLocation, s3ak, s3pk, s3ek);
            } catch (AmazonClientException exception) {
                // Add helpful text to Exception
                String systemError = String.format(
                        "Could not retrieve File Bytes for S3 File. Failed with Message : %s. AWS Client Credentials may be incorrect or not specified.",
                        exception.getMessage());
                String userError = "There was an issue pushing the file to Piazza S3 Bucket. Please contact a Piazza administrator for details.";
                LOGGER.error(systemError, exception);
                throw new AmazonClientException(userError);
            }
        } else {
            throw new InvalidInputException("Unsupported Object type.");
        }
    }

    /**
     * Gets the input stream for an S3 file store. This will stream the bytes from S3. Null, or exception will be thrown
     * if an error occurs during acquisition.
     * 
     * The S3 Credentials MUST be populated using the setCredentials() method before executing this call, or a
     * Credentials exception is likely to be thrown by S3.
     */
    @JsonIgnore
    public InputStream getS3File(FileLocation fileLocation, String accessKey, String privateKey,
            String s3EncryptKey) {
        // Get the file from S3. Connect to S3 Bucket. Only apply credentials if they are present.
        final AmazonS3Client s3Client;
        S3FileStore fileStore = (S3FileStore) fileLocation;
        if (accessKey.isEmpty() || privateKey.isEmpty()) {
            s3Client = new AmazonS3Client();
        } else {
            // If an encryption key was provided, use the encrypted client
            BasicAWSCredentials credentials = new BasicAWSCredentials(accessKey, privateKey);
            if (s3EncryptKey != null) {
                KMSEncryptionMaterialsProvider materialProvider = new KMSEncryptionMaterialsProvider(s3EncryptKey);
                s3Client = new AmazonS3EncryptionClient(credentials, materialProvider,
                        new CryptoConfiguration().withKmsRegion(Regions.US_EAST_1))
                                .withRegion(Region.getRegion(Regions.US_EAST_1));
            } else {
                s3Client = new AmazonS3Client(credentials);
            }
        }
        S3Object s3Object = s3Client.getObject(fileStore.getBucketName(), fileStore.getFileName());
        return s3Object.getObjectContent();
    }

    /**
     * Returns the URI for a file represented by an object implementing the FileLocation interface
     * 
     * @param fileLocation
     *            The file location
     * @return The File URI
     */
    public String getFileUri(FileLocation fileLocation) throws InvalidInputException {
        if (fileLocation instanceof FolderShare) {
            return ((FolderShare) fileLocation).getFilePath();
        } else if (fileLocation instanceof S3FileStore) {
            S3FileStore s3FileStore = (S3FileStore) fileLocation;
            return String.format("%s%s/%s/%s", PROTOCOL_PREFIX, s3FileStore.getDomainName(),
                    s3FileStore.getBucketName(), s3FileStore.getFileName());
        } else {
            throw new InvalidInputException("Unsupported Object type.");
        }
    }
}