Java tutorial
/* * Copyright 2010-2016 ksyun.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://ksyun.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.ksc; import com.ksc.annotation.SdkProtectedApi; import com.ksc.auth.RegionAwareSigner; import com.ksc.auth.Signer; import com.ksc.auth.SignerFactory; import com.ksc.handlers.RequestHandler; import com.ksc.handlers.RequestHandler2; import com.ksc.http.KSCHttpClient; import com.ksc.http.ExecutionContext; import com.ksc.internal.DefaultServiceEndpointBuilder; import com.ksc.log.CommonsLogFactory; import com.ksc.metrics.KscSdkMetrics; import com.ksc.metrics.RequestMetricCollector; import com.ksc.regions.Region; import com.ksc.regions.Regions; import com.ksc.util.*; import com.ksc.util.KscRequestMetrics.Field; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.net.URI; import java.util.List; import java.util.concurrent.CopyOnWriteArrayList; import static com.ksc.SDKGlobalConfiguration.PROFILING_SYSTEM_PROPERTY; /** * Abstract base class for Ksc Web Service Java clients. * <p> * Responsible for basic client capabilities that are the same across all KSC * SDK Java clients (ex: setting the client endpoint). */ @SuppressWarnings("deprecation") public abstract class KscWebServiceClient { private static final String KSYUN = "Ksyun"; private static final String KSC = "KSC"; public static final boolean LOGGING_AWS_REQUEST_METRIC = true; private static final Log log = LogFactory.getLog(KscWebServiceClient.class); static { // Configures the internal logging of the signers and core // classes to use Jakarta Commons Logging to stay consistent with the // rest of the library. boolean success = com.ksc.log.InternalLogFactory.configureFactory(new CommonsLogFactory()); if (log.isDebugEnabled()) log.debug("Internal logging succesfully configured to commons logger: " + success); } /** * The service endpoint to which this client will send requests. * <p> * Subclass should only read but not assign to this field, at least not * without synchronization on the enclosing object for thread-safety * reason. */ protected volatile URI endpoint; /** * Used to explicitly override the internal signer region computed by the * default implementation. This field is typically null. */ private volatile String signerRegionOverride; /** The client configuration */ protected ClientConfiguration clientConfiguration; /** Low level client for sending requests to AWS services. */ protected KSCHttpClient client; /** Optional request handlers for additional request processing. */ protected final List<RequestHandler2> requestHandler2s; /** Optional offset (in seconds) to use when signing requests */ protected int timeOffset; /** AWS signer for authenticating requests. */ private volatile Signer signer; /** * The cached service abbreviation for this service, used for identifying * service endpoints by region, identifying the necessary signer, etc. * Thread safe so it's backward compatible. */ private volatile String serviceName; /** * The service name in region metadata, i.e. the prefix of endpoint. */ private volatile String endpointPrefix; /** * Constructs a new KscWebServiceClient object using the specified * configuration. * * @param clientConfiguration * The client configuration for this client. */ public KscWebServiceClient(ClientConfiguration clientConfiguration) { this(clientConfiguration, null); } /** * Constructs a new KscWebServiceClient object using the specified * configuration and request metric collector. * * @param clientConfiguration * The client configuration for this client. * @param requestMetricCollector * optional request metric collector to be used at the http * client level; can be null. */ public KscWebServiceClient(ClientConfiguration clientConfiguration, RequestMetricCollector requestMetricCollector) { this(clientConfiguration, requestMetricCollector, false); } @SdkProtectedApi protected KscWebServiceClient(ClientConfiguration clientConfiguration, RequestMetricCollector requestMetricCollector, boolean disableStrictHostNameVerification) { this.clientConfiguration = clientConfiguration; requestHandler2s = new CopyOnWriteArrayList<RequestHandler2>(); client = new KSCHttpClient(clientConfiguration, requestMetricCollector, disableStrictHostNameVerification); } /** * Returns the signer. * <p> * Note, however, the signer configured for S3 is incomplete at this stage * as the information on the S3 bucket and key is not yet known. */ protected Signer getSigner() { return signer; } /** * Overrides the default endpoint for this client. Callers can use this * method to control which AWS region they want to work with. * <p> * <b>This method is not threadsafe. Endpoints should be configured when the * client is created and before any service requests are made. Changing it * afterwards creates inevitable race conditions for any service requests in * transit.</b> * <p> * Callers can pass in just the endpoint (ex: "kec.ksyun.com") or a full * URL, including the protocol (ex: "https://kec.ksyun.com"). If the * protocol is not specified here, the default protocol from this client's * {@link ClientConfiguration} will be used, which by default is HTTPS. * <p> * For more information on using AWS regions with the AWS SDK for Java, and * a complete list of all available endpoints for all AWS services, see: * <a href="http://developer.amazonwebservices.com/connect/entry.jspa?externalID=3912"> * http://developer.amazonwebservices.com/connect/entry.jspa?externalID=3912</a> * * @param endpoint * The endpoint (ex: "kec.ksyun.com") or a full URL, * including the protocol (ex: "https://kec.ksyun.com") of * the region specific AWS endpoint this client will communicate * with. * @throws IllegalArgumentException * If any problems are detected with the specified endpoint. */ public void setEndpoint(String endpoint) throws IllegalArgumentException { URI uri = toURI(endpoint); Signer signer = computeSignerByURI(uri, signerRegionOverride, false); synchronized (this) { this.endpoint = uri; this.signer = signer; } } /** Returns the endpoint as a URI. */ private URI toURI(String endpoint) throws IllegalArgumentException { return RuntimeHttpUtils.toUri(endpoint, clientConfiguration); } /** * Returns the signer based on the given URI and the current AWS client * configuration. Currently only the SQS client can have different region on * a per request basis. For other AWS clients, the region remains the same * on a per AWS client level. * <p> * Note, however, the signer returned for S3 is incomplete at this stage as * the information on the S3 bucket and key is not yet known. */ public Signer getSignerByURI(URI uri) { return computeSignerByURI(uri, signerRegionOverride, true); } /** * Returns the signer for the given uri and the current client * configuration. * <p> * Note, however, the signer returned for S3 is incomplete at this stage as * the information on the S3 bucket and key is not yet known. * * @param signerRegionOverride * the overriding signer region; or null if there is none. * @param isRegionIdAsSignerParam * true if the "regionId" is used to configure the signer if * applicable; false if this method is called for the purpose of * purely setting the communication end point of this AWS client, * and therefore the "regionId" parameter will not be used * directly for configuring the signer. */ private Signer computeSignerByURI(URI uri, String signerRegionOverride, boolean isRegionIdAsSignerParam) { if (uri == null) { throw new IllegalArgumentException( "Endpoint is not set. Use setEndpoint to set an endpoint before performing any request."); } String service = getServiceNameIntern(); String region = KscHostNameUtils.parseRegionName(uri.getHost(), service); return computeSignerByServiceRegion(service, region, signerRegionOverride, isRegionIdAsSignerParam); } /** * Returns the signer for the given service name, region id, and the current * client configuration. * <p> * Note, however, the signer returned for S3 is incomplete at this stage as * the information on the S3 bucket and key is not yet known. * * @param regionId * the region for sending AWS requests * @param signerRegionOverride * the overriding signer region; or null if there is none. * @param isRegionIdAsSignerParam * true if the "regionId" is used to configure the signer if * applicable; false if this method is called for the purpose of * purely setting the communication end point of this AWS client, * and therefore the "regionId" parameter will not be used * directly for configuring the signer. */ private Signer computeSignerByServiceRegion(String serviceName, String regionId, String signerRegionOverride, boolean isRegionIdAsSignerParam) { String signerType = clientConfiguration.getSignerOverride(); Signer signer = signerType == null ? SignerFactory.getSigner(serviceName, regionId) : SignerFactory.getSignerByTypeAndService(signerType, serviceName); if (signer instanceof RegionAwareSigner) { // Overrides the default region computed RegionAwareSigner regionAwareSigner = (RegionAwareSigner) signer; // (signerRegionOverride != null) means that it is likely to be AWS // internal dev work, as "signerRegionOverride" is typically null // when used in the external release if (signerRegionOverride != null) regionAwareSigner.setRegionName(signerRegionOverride); else if (regionId != null && isRegionIdAsSignerParam) regionAwareSigner.setRegionName(regionId); } return signer; } /** * An alternative to {@link KscWebServiceClient#setEndpoint(String)}, sets the regional * endpoint for this client's service calls. Callers can use this method to control which AWS * region they want to work with. * <p> * <b>This method is not threadsafe. A region should be configured when the client is created * and before any service requests are made. Changing it afterwards creates inevitable race * conditions for any service requests in transit or retrying.</b> * <p> * By default, all service endpoints in all regions use the https protocol. To use http instead, * specify it in the {@link ClientConfiguration} supplied at construction. * * @param region * The region this client will communicate with. See * {@link Region#getRegion(com.ksc.regions.Regions)} for accessing a given * region. * @throws java.lang.IllegalArgumentException * If the given region is null, or if this service isn't available in the given * region. See {@link Region#isServiceSupported(String)} * @see Region#getRegion(com.ksc.regions.Regions) * @see Region#createClient(Class, com.ksc.auth.AWSCredentialsProvider, * ClientConfiguration) */ public void setRegion(Region region) throws IllegalArgumentException { if (region == null) { throw new IllegalArgumentException("No region provided"); } final String serviceNameForEndpoint = getEndpointPrefix(); final String serviceNameForSigner = getServiceNameIntern(); URI uri = new DefaultServiceEndpointBuilder(serviceNameForEndpoint, clientConfiguration.getProtocol().toString()).withRegion(region).getServiceEndpoint(); Signer signer = computeSignerByServiceRegion(serviceNameForSigner, region.getName(), signerRegionOverride, false); synchronized (this) { this.endpoint = uri; this.signer = signer; } } /** * Convenient method for setting region. * * @param region region to set to; must not be null. * * @see #setRegion(Region) */ public final void configureRegion(Regions region) { if (region == null) throw new IllegalArgumentException("No region provided"); this.setRegion(Region.getRegion(region)); } /** * Shuts down this client object, releasing any resources that might be held * open. This is an optional method, and callers are not expected to call * it, but can if they want to explicitly release any open resources. Once a * client has been shutdown, it should not be used to make any more * requests. */ public void shutdown() { client.shutdown(); } /** * @deprecated by {@link #addRequestHandler(RequestHandler2)}. * * Appends a request handler to the list of registered handlers that are run * as part of a request's lifecycle. * * @param requestHandler * The new handler to add to the current list of request * handlers. */ @Deprecated public void addRequestHandler(RequestHandler requestHandler) { requestHandler2s.add(RequestHandler2.adapt(requestHandler)); } /** * Appends a request handler to the list of registered handlers that are run * as part of a request's lifecycle. * * @param requestHandler2 * The new handler to add to the current list of request * handlers. */ public void addRequestHandler(RequestHandler2 requestHandler2) { requestHandler2s.add(requestHandler2); } /** * Removes a request handler from the list of registered handlers that are run * as part of a request's lifecycle. * * @param requestHandler * The handler to remove from the current list of request * handlers. */ public void removeRequestHandler(RequestHandler requestHandler) { requestHandler2s.remove(RequestHandler2.adapt(requestHandler)); } public void removeRequestHandler(RequestHandler2 requestHandler2) { requestHandler2s.remove(requestHandler2); } /** * Runs the {@code beforeMarshalling} method of any * {@code RequestHandler2}s associated with this client. * * @param request the request passed in from the user * @return the (possibly different) request to marshal */ @SuppressWarnings("unchecked") protected final <T extends KscWebServiceRequest> T beforeMarshalling(T request) { T local = request; for (RequestHandler2 handler : requestHandler2s) { local = (T) handler.beforeMarshalling(local); } return local; } protected ExecutionContext createExecutionContext(KscWebServiceRequest req) { boolean isMetricsEnabled = isRequestMetricsEnabled(req) || isProfilingEnabled(); return new ExecutionContext(requestHandler2s, isMetricsEnabled, this); } protected final ExecutionContext createExecutionContext(Request<?> req) { return createExecutionContext(req.getOriginalRequest()); } /** * @deprecated by {@link #createExecutionContext(KscWebServiceRequest)}. * * This method exists only for backward compatiblity reason, so * that clients compiled against the older version of this class * won't get {@link NoSuchMethodError} at runtime. However, * calling this methods would effectively ignore and disable the * request metric collector, if any, specified at the request * level. Request metric collector specified at the service * client or AWS SDK level will still be honored. */ @Deprecated protected final ExecutionContext createExecutionContext() { boolean isMetricsEnabled = isRMCEnabledAtClientOrSdkLevel() || isProfilingEnabled(); return new ExecutionContext(requestHandler2s, isMetricsEnabled, this); } /* Check the profiling system property and return true if set */ protected static boolean isProfilingEnabled() { return System.getProperty(PROFILING_SYSTEM_PROPERTY) != null; } /** * Returns true if request metric collection is applicable to the given * request; false otherwise. */ protected final boolean isRequestMetricsEnabled(KscWebServiceRequest req) { RequestMetricCollector c = req.getRequestMetricCollector(); // request level collector if (c != null && c.isEnabled()) { return true; } return isRMCEnabledAtClientOrSdkLevel(); } /** * Returns true if request metric collection is enabled at the service * client or AWS SDK level request; false otherwise. */ private boolean isRMCEnabledAtClientOrSdkLevel() { RequestMetricCollector c = requestMetricCollector(); return c != null && c.isEnabled(); } /** * Sets the optional value for time offset for this client. This * value will be applied to all requests processed through this client. * Value is in seconds, positive values imply the current clock is "fast", * negative values imply clock is slow. * * @param timeOffset * The optional value for time offset (in seconds) for this client. */ public void setTimeOffset(int timeOffset) { this.timeOffset = timeOffset; } /** * Sets the optional value for time offset for this client. This * value will be applied to all requests processed through this client. * Value is in seconds, positive values imply the current clock is "fast", * negative values imply clock is slow. * * @param timeOffset * The optional value for time offset (in seconds) for this client. * * @return the updated web service client */ public KscWebServiceClient withTimeOffset(int timeOffset) { setTimeOffset(timeOffset); return this; } /** * Returns the optional value for time offset for this client. This * value will be applied to all requests processed through this client. * Value is in seconds, positive values imply the current clock is "fast", * negative values imply clock is slow. * * @return The optional value for time offset (in seconds) for this client. */ public int getTimeOffset() { return timeOffset; } /** * Returns the client specific {@link RequestMetricCollector}; or null if * there is none. */ public RequestMetricCollector getRequestMetricsCollector() { return client.getRequestMetricCollector(); } /** * Returns the client specific request metric collector if there is one; or * the one at the AWS SDK level otherwise. */ protected RequestMetricCollector requestMetricCollector() { RequestMetricCollector mc = client.getRequestMetricCollector(); return mc == null ? KscSdkMetrics.getRequestMetricCollector() : mc; } /** * Returns the most specific request metric collector, starting from the * request level, then client level, then finally the AWS SDK level. */ protected final RequestMetricCollector findRequestMetricCollector(Request<?> req) { KscWebServiceRequest origReq = req.getOriginalRequest(); RequestMetricCollector mc = origReq.getRequestMetricCollector(); if (mc != null) { return mc; } mc = getRequestMetricsCollector(); return mc == null ? KscSdkMetrics.getRequestMetricCollector() : mc; } /** * Convenient method to end the client execution without logging the * awsRequestMetrics. */ protected final void endClientExecution(KscRequestMetrics awsRequestMetrics, Request<?> request, Response<?> response) { this.endClientExecution(awsRequestMetrics, request, response, !LOGGING_AWS_REQUEST_METRIC); } /** * Common routine to end a client AWS request/response execution and collect * the request metrics. Caller of this routine is responsible for starting * the event for {@link Field#ClientExecuteTime} and call this method * in a try-finally block. * * @param loggingAwsRequestMetrics deprecated and ignored */ protected final void endClientExecution(KscRequestMetrics awsRequestMetrics, Request<?> request, Response<?> response, @Deprecated boolean loggingAwsRequestMetrics) { if (request != null) { awsRequestMetrics.endEvent(Field.ClientExecuteTime); awsRequestMetrics.getTimingInfo().endTiming(); RequestMetricCollector c = findRequestMetricCollector(request); c.collectMetrics(request, response); awsRequestMetrics.log(); } } /** * @deprecated by {@link #getServiceName()}. */ @Deprecated protected String getServiceAbbreviation() { return getServiceNameIntern(); } /** * Returns the service abbreviation for this service, used for identifying * service endpoints by region, identifying the necessary signer, etc. * Used to be call "getServiceAbbreviation". */ public String getServiceName() { return getServiceNameIntern(); } /** * @return the service name that should be used when computing the region * endpoints. This method returns the value of the * regionMetadataServiceName configuration in the internal config * file if such configuration is specified for the current client, * otherwise it returns the same service name that is used for * request signing. */ public String getEndpointPrefix() { if (endpointPrefix != null) return endpointPrefix; String httpClientName = getHttpClientName(); String serviceNameInRegionMetadata = ServiceNameFactory.getServiceNameInRegionMetadata(httpClientName); synchronized (this) { if (endpointPrefix != null) return endpointPrefix; if (serviceNameInRegionMetadata != null) { return endpointPrefix = serviceNameInRegionMetadata; } else { return endpointPrefix = getServiceNameIntern(); } } } /** * An internal method used to explicitly override the service name for region metadata. * This service name is used to compute the region endpoints. */ protected void setEndpointPrefix(String endpointPrefix) { if (endpointPrefix == null) { throw new IllegalArgumentException("The parameter endpointPrefix must be specified!"); } this.endpointPrefix = endpointPrefix; } /** * Internal method for implementing {@link #getServiceName()}. Method is * protected by intent so peculiar subclass that don't follow the class * naming convention can choose to return whatever service name as needed. */ protected String getServiceNameIntern() { if (serviceName == null) { synchronized (this) { if (serviceName == null) { return serviceName = computeServiceName(); } } } return serviceName; } /** * An internal method used to explicitly override the service name * computed by the default implementation. This method is not expected to be * normally called except for AWS internal development purposes. */ public final void setServiceNameIntern(String serviceName) { if (serviceName == null) throw new IllegalArgumentException("The parameter serviceName must be specified!"); this.serviceName = serviceName; } /** * Returns the service name of this AWS http client by first looking it up * from the SDK internal configuration, and if not found, derive it from the * class name of the immediate subclass of {@link KscWebServiceClient}. * No configuration is necessary if the simple class name of the http client * follows the convention of <code>(ksyun|KSC).*(JavaClient|Client)</code>. */ private String computeServiceName() { final String httpClientName = getHttpClientName(); String service = ServiceNameFactory.getServiceName(httpClientName); if (service != null) { return service; // only if it is so explicitly configured } // Otherwise, make use of convention over configuration int j = httpClientName.indexOf("JavaClient"); if (j == -1) { j = httpClientName.indexOf("Client"); if (j == -1) { throw new IllegalStateException( "Unrecognized suffix for the AWS http client class name " + httpClientName); } } int i = httpClientName.indexOf(KSYUN); int len; if (i == -1) { i = httpClientName.indexOf(KSC); if (i == -1) { throw new IllegalStateException( "Unrecognized prefix for the KSC http client class name " + httpClientName); } len = KSC.length(); } else { len = KSYUN.length(); } if (i >= j) { throw new IllegalStateException("Unrecognized AWS http client class name " + httpClientName); } String serviceName = httpClientName.substring(i + len, j); return StringUtils.lowerCase(serviceName); } private String getHttpClientName() { Class<?> httpClientClass = Classes.childClassOf(KscWebServiceClient.class, this); return httpClientClass.getSimpleName(); } /** * Returns the signer region override. * * @see #setSignerRegionOverride(String). */ public final String getSignerRegionOverride() { return signerRegionOverride; } /** * An internal method used to explicitly override the internal signer region * computed by the default implementation. This method is not expected to be * normally called except for AWS internal development purposes. */ public final void setSignerRegionOverride(String signerRegionOverride) { Signer signer = computeSignerByURI(endpoint, signerRegionOverride, true); synchronized (this) { this.signer = signer; this.signerRegionOverride = signerRegionOverride; } } /** * Fluent method for {@link #setRegion(Region)}. *<pre> * Example: * * AmazonDynamoDBClient client = new AmazonDynamoDBClient(...).<AmazonDynamoDBClient>withRegion(...); *</pre> * @see #setRegion(Region) */ public <T extends KscWebServiceClient> T withRegion(Region region) { setRegion(region); @SuppressWarnings("unchecked") T t = (T) this; return t; } /** * Convenient fluent method for setting region. * * @param region region to set to; must not be null. * * @see #withRegion(Region) */ public <T extends KscWebServiceClient> T withRegion(Regions region) { configureRegion(region); @SuppressWarnings("unchecked") T t = (T) this; return t; } /** * Fluent method for {@link #setEndpoint(String)}. *<pre> * Example: * * AmazonDynamoDBClient client = new AmazonDynamoDBClient(...).<AmazonDynamoDBClient>withEndPoint(...); *</pre> * @see #setEndpoint(String) */ public <T extends KscWebServiceClient> T withEndpoint(String endpoint) { setEndpoint(endpoint); @SuppressWarnings("unchecked") T t = (T) this; return t; } }