SDKGlobalConfiguration.java

/*
 * Copyright 2010-2014 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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 com.amazonaws;

import com.amazonaws.http.AmazonHttpClient;


/**
 * SDKGlobalConfiguration is to configure any global settings
 */
public class SDKGlobalConfiguration {
    /////////////////////// System Properties ///////////////////////

    /**
     * Disable validation of server certificates when using the HTTPS protocol.
     * This should ONLY be used to do quick smoke tests against endpoints which
     * don't yet have valid certificates; it should NEVER be used in
     * production.
     */
    public static final String DISABLE_CERT_CHECKING_SYSTEM_PROPERTY =
        "com.amazonaws.sdk.disableCertChecking";

    /**
     * System property used when starting up the JVM to enable the default
     * metrics collected by the AWS SDK, which uploads the derived statistics
     * to Amazon CloudWatch.
     *
     * <pre>
     * Example:
     *  -Dcom.amazonaws.sdk.enableDefaultMetrics
     * </pre>
     */
    public static final String DEFAULT_METRICS_SYSTEM_PROPERTY =
        "com.amazonaws.sdk.enableDefaultMetrics";

    /** System property name for the AWS access key ID */
    public static final String ACCESS_KEY_SYSTEM_PROPERTY = "aws.accessKeyId";

    /** System property name for the AWS secret key */
    public  static final String SECRET_KEY_SYSTEM_PROPERTY = "aws.secretKey";

    /**
     * System property for overriding the Amazon EC2 Instance Metadata Service
     * endpoint.
     */
    public static final String EC2_METADATA_SERVICE_OVERRIDE_SYSTEM_PROPERTY =
        "com.amazonaws.sdk.ec2MetadataServiceEndpointOverride";

    /**
     * Path to an override file for the region metadata loaded by the SDK
     * that maps service/region pairs to endpoints and vice versa.
     */
    public static final String REGIONS_FILE_OVERRIDE_SYSTEM_PROPERTY =
        "com.amazonaws.regions.RegionUtils.fileOverride";

    /**
     * By default, the SDK will attempt to download an up-to-date set of
     * region metadata from Amazon CloudFront when first required. This allows
     * you to look up information about new regions and services without having
     * to download a new version of the SDK every time.
     * <p>
     * If the SDK cannot download region metadata from Amazon CloudFront, it
     * will fall back to loading the region metadata bundled with the SDK when
     * it was released, which may be out of date.
     * <p>
     * Setting this system property to anything other than {@code null} will
     * <i>disable</i> this remote fetching, and will <i>only</i> load region
     * metadata that was bundled with the SDK. This gives you control over
     * when new region metadata will be picked up by your application, and
     * isolates you from potential issues if your application depends on being
     * able to load metadata about a region which is not included in your
     * version of the SDK and therefore may not be available in the event of
     * network outages.
     */
    public static final String DISABLE_REMOTE_REGIONS_FILE_SYSTEM_PROPERTY =
        "com.amazonaws.regions.RegionUtils.disableRemote";

    /**
     * By default, the AmazonS3Client will continue to use the legacy
     * S3Signer to authenticate requests it makes to S3 in regions that
     * support the older protocol. Setting this property to anything other
     * than null will cause the client to upgrade to Signature Version 4
     * whenever it has been configured with an explicit region (which is a
     * required parameter for Signature Version 4). The client will continue
     * to use the older signature protocol when not configured with a region
     * to avoid breaking existing applications.
     * <p>
     * Signature Version 4 is more secure than the legacy S3Signer, but
     * requires calculating a SHA-256 hash of the entire request body which
     * can be expensive for large upload requests.
     */
    public static final String ENABLE_S3_SIGV4_SYSTEM_PROPERTY =
        "com.amazonaws.services.s3.enableV4";

    /**
     * Like {@link #ENABLE_S3_SIGV4_SYSTEM_PROPERTY}, but causes the client to
     * always use Signature Version 4, assuming a region of
     * &quot;us-east-1&quot; if no explicit region has been configured. This
     * guarantees that the more secure authentication protocol will be used,
     * but will cause authentication failures in code that accesses buckets in
     * regions other than US Standard without explicitly configuring a region.
     */
    public static final String ENFORCE_S3_SIGV4_SYSTEM_PROPERTY =
        "com.amazonaws.services.s3.enforceV4";

    /**
     * @deprecated with {@link AmazonWebServiceRequest#getRequestClientOptions()}
     * and {@link RequestClientOptions#setReadLimit(int)}.
     * <p>
     * The default size of the buffer when uploading data from a stream. A
     * buffer of this size will be created and filled with the first bytes from
     * a stream being uploaded so that any transmit errors that occur in that
     * section of the data can be automatically retried without the caller's
     * intervention.
     * <p>
     * If not set, the default value of 128 KB will be used.
     */
    @Deprecated
    public static final String DEFAULT_S3_STREAM_BUFFER_SIZE =
        "com.amazonaws.sdk.s3.defaultStreamBufferSize";

    /**
     * @deprecated by {@link #DEFAULT_METRICS_SYSTEM_PROPERTY}.
     *
     * Internal system property to enable timing info collection.
     */
    @Deprecated
    public static final String PROFILING_SYSTEM_PROPERTY =
        "com.amazonaws.sdk.enableRuntimeProfiling";

    /////////////////////// Environment Variables ///////////////////////
    /** Environment variable name for the AWS access key ID */
    public static final String ACCESS_KEY_ENV_VAR = "AWS_ACCESS_KEY_ID";

    /** Alternate environment variable name for the AWS access key ID */
    public static final String ALTERNATE_ACCESS_KEY_ENV_VAR = "AWS_ACCESS_KEY";

    /** Environment variable name for the AWS secret key */
    public static final String SECRET_KEY_ENV_VAR = "AWS_SECRET_KEY";

    /** Alternate environment variable name for the AWS secret key */
    public static final String ALTERNATE_SECRET_KEY_ENV_VAR = "AWS_SECRET_ACCESS_KEY";

    /** Environment variable name for the AWS session token */
    public static final String AWS_SESSION_TOKEN_ENV_VAR = "AWS_SESSION_TOKEN";

    /**
     * globalTimeOffset is a time difference in seconds between the running JVM
     * and AWS. Used to globally adjust the client clock skew. Java SDK already
     * provides timeOffset and accessor methods in {@link Request} class but
     * those are used per request, whereas this variable will adjust clock skew
     * globally. Java SDK detects clock skew errors and adjusts global clock
     * skew automatically.
     */
    private static volatile int globalTimeOffset;

    /**
     * Sets the global time difference in seconds between the running JVM and
     * AWS. If this value is set then all the subsequent instantiation of an
     * {@link AmazonHttpClient} will start using this
     * value to generate timestamps.
     *
     * @param timeOffset
     *            the time difference in seconds between the running JVM and AWS
     */
    public  static void setGlobalTimeOffset(int timeOffset) {
        globalTimeOffset = timeOffset;
    }

    /**
     * Gets the global time difference in seconds between the running JVM and
     * AWS. See {@link Request#getTimeOffset()} if global time offset is
     * not set.
     */
    public static int getGlobalTimeOffset() {
        return globalTimeOffset;
    }
}