[ACL-263] Caching improvements (#337)

Author: dili91

.github/pull_request_template.md

@@ -16,7 +16,7 @@ Please select multiple options if required.
 # Checklist:
 
 - [ ] I have updated the `gradle.properties` file with the new version
-- [ ] I have updated the `CHANGELOG.md` file with the details of the new versio
+- [ ] I have updated the `CHANGELOG.md` file with the details of the new version
 - [ ] My code follows the style guidelines of this project
 - [ ] I have performed a self-review of my own code
 - [ ] I have commented my code where necessary

CHANGELOG.md

@@ -5,7 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/).
 
-## [Unreleased]
+## [17.0.0] - 2025-01-15
+### Changed
+* ⚠️ Breaking: removed deprecated HPP link builder
+* ⚠️ Breaking: Aligned custom cache implementation to other officially supported client libraries
 
 ## [16.3.1] - 2025-01-10
 ### Changed

gradle.properties

@@ -1,7 +1,7 @@
 # Main properties
 group=com.truelayer
 archivesBaseName=truelayer-java
-version=16.3.1
+version=17.0.0
 
 # Artifacts properties
 sonatype_repository_url=https://s01.oss.sonatype.org/service/local/

src/main/java/com/truelayer/java/ITrueLayerClient.java

@@ -3,7 +3,6 @@
 import com.truelayer.java.auth.IAuthenticationHandler;
 import com.truelayer.java.commonapi.entities.SubmitPaymentsProviderReturnRequest;
 import com.truelayer.java.commonapi.entities.SubmitPaymentsProviderReturnResponse;
-import com.truelayer.java.hpp.IHostedPaymentPageLinkBuilder;
 import com.truelayer.java.http.entities.ApiResponse;
 import com.truelayer.java.mandates.IMandatesHandler;
 import com.truelayer.java.merchantaccounts.IMerchantAccountsHandler;
@@ -60,14 +59,6 @@ public interface ITrueLayerClient {
      */
     ISignupPlusHandler signupPlus();
 
-    /**
-     * Entrypoint for Hosted Payment Page related services.
-     * @return a utility to build a Hosted Payment Page URL.
-     * @deprecated use {@link #hppLinkBuilder()} instead.
-     */
-    @Deprecated
-    IHostedPaymentPageLinkBuilder hpp();
-
     /**
      * Entrypoint for Hosted Payment Page related services.
      * @return a utility to build a Hosted Payment Page URL.

src/main/java/com/truelayer/java/TrueLayerClient.java

@@ -4,7 +4,6 @@
 import com.truelayer.java.commonapi.ICommonHandler;
 import com.truelayer.java.commonapi.entities.SubmitPaymentsProviderReturnRequest;
 import com.truelayer.java.commonapi.entities.SubmitPaymentsProviderReturnResponse;
-import com.truelayer.java.hpp.IHostedPaymentPageLinkBuilder;
 import com.truelayer.java.http.entities.ApiResponse;
 import com.truelayer.java.mandates.IMandatesHandler;
 import com.truelayer.java.merchantaccounts.IMerchantAccountsHandler;
@@ -33,23 +32,14 @@ public class TrueLayerClient implements ITrueLayerClient {
     private IPayoutsHandler payoutsHandler;
     private ISignupPlusHandler signupPlusHandler;
     private ICommonHandler commonHandler;
-
-    /**
-     * @deprecated - use {@link #hostedPaymentPageLinkBuilder} instead.
-     */
-    @Deprecated
-    private IHostedPaymentPageLinkBuilder hppLinkBuilder;
-
     private HostedPaymentPageLinkBuilder hostedPaymentPageLinkBuilder;
 
     public TrueLayerClient(
             IAuthenticationHandler authenticationHandler,
-            IHostedPaymentPageLinkBuilder hostedPaymentPageLinkBuilder,
             ICommonHandler commonHandler,
             ISignupPlusHandler signupPlusHandler,
             HostedPaymentPageLinkBuilder hppLinkBuilder) {
         this.authenticationHandler = authenticationHandler;
-        this.hppLinkBuilder = hostedPaymentPageLinkBuilder;
         this.commonHandler = commonHandler;
         this.signupPlusHandler = signupPlusHandler;
         this.hostedPaymentPageLinkBuilder = hppLinkBuilder;
@@ -128,15 +118,6 @@ public ISignupPlusHandler signupPlus() {
         return signupPlusHandler;
     }
 
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    @Deprecated
-    public IHostedPaymentPageLinkBuilder hpp() {
-        return this.hppLinkBuilder;
-    }
-
     @Override
     public HostedPaymentPageLinkBuilder hppLinkBuilder() {
         return this.hostedPaymentPageLinkBuilder;

src/main/java/com/truelayer/java/TrueLayerClientBuilder.java

@@ -9,11 +9,10 @@
 import com.truelayer.java.commonapi.ICommonApi;
 import com.truelayer.java.commonapi.ICommonHandler;
 import com.truelayer.java.entities.RequestScopes;
-import com.truelayer.java.hpp.IHostedPaymentPageLinkBuilder;
 import com.truelayer.java.http.OkHttpClientFactory;
 import com.truelayer.java.http.RetrofitFactory;
 import com.truelayer.java.http.auth.cache.ICredentialsCache;
-import com.truelayer.java.http.auth.cache.SimpleCredentialsCache;
+import com.truelayer.java.http.auth.cache.InMemoryCredentialsCache;
 import com.truelayer.java.http.interceptors.logging.DefaultLogConsumer;
 import com.truelayer.java.mandates.IMandatesApi;
 import com.truelayer.java.mandates.IMandatesHandler;
@@ -72,6 +71,9 @@ public class TrueLayerClientBuilder {
 
     private Consumer<String> logMessageConsumer;
 
+    /**
+     * Holder for the cache implementation. Null if caching is disabled
+     */
     private ICredentialsCache credentialsCache;
 
     private ProxyConfiguration proxyConfiguration;
@@ -182,12 +184,13 @@ public TrueLayerClientBuilder withHttpLogs(Consumer<String> logConsumer) {
      * @return the instance of the client builder used
      */
     public TrueLayerClientBuilder withCredentialsCaching() {
-        this.credentialsCache = new SimpleCredentialsCache(Clock.systemUTC());
+        this.credentialsCache = new InMemoryCredentialsCache(Clock.systemUTC());
         return this;
     }
 
     /**
      * Utility to enable a custom cache for Oauth credentials.
+     * @param credentialsCache the custom cache implementation
      * @return the instance of the client builder used
      */
     public TrueLayerClientBuilder withCredentialsCaching(ICredentialsCache credentialsCache) {
@@ -228,10 +231,6 @@ public TrueLayerClient build() {
                 .httpClient(RetrofitFactory.build(authServerApiHttpClient, environment.getAuthApiUri()))
                 .build();
 
-        IHostedPaymentPageLinkBuilder hppLinkBuilder = com.truelayer.java.hpp.HostedPaymentPageLinkBuilder.New()
-                .uri(environment.getHppUri())
-                .build();
-
         // We're reusing a client with only User agent and Idempotency key interceptors and give it our base payment
         // endpoint
         ICommonApi commonApi = RetrofitFactory.build(authServerApiHttpClient, environment.getPaymentsApiUri())
@@ -241,7 +240,7 @@ public TrueLayerClient build() {
         // We're building a client which has the authentication handler and the options to cache the token.
         // this one represents the baseline for the client used for Signup+ and Payments
         OkHttpClient authenticatedApiClient = httpClientFactory.buildAuthenticatedApiClient(
-                authServerApiHttpClient, authenticationHandler, credentialsCache);
+                clientCredentials.clientId, authServerApiHttpClient, authenticationHandler, credentialsCache);
         ISignupPlusApi signupPlusApi = RetrofitFactory.build(authenticatedApiClient, environment.getPaymentsApiUri())
                 .create(ISignupPlusApi.class);
         SignupPlusHandler.SignupPlusHandlerBuilder signupPlusHandlerBuilder =
@@ -256,7 +255,6 @@ public TrueLayerClient build() {
         if (isEmpty(signingOptions)) {
             return new TrueLayerClient(
                     authenticationHandler,
-                    hppLinkBuilder,
                     commonHandler,
                     signupPlusHandler,
                     new HostedPaymentPageLinkBuilder(environment));
@@ -324,7 +322,6 @@ public TrueLayerClient build() {
                 payoutsHandler,
                 signupPlusHandler,
                 commonHandler,
-                hppLinkBuilder,
                 new HostedPaymentPageLinkBuilder(environment));
     }
 

src/main/java/com/truelayer/java/http/OkHttpClientFactory.java

@@ -108,6 +108,7 @@ public OkHttpClient buildAuthServerApiClient(OkHttpClient baseHttpClient, Client
     }
 
     public OkHttpClient buildAuthenticatedApiClient(
+            String clientId,
             OkHttpClient authServerApiClient,
             IAuthenticationHandler authenticationHandler,
             ICredentialsCache credentialsCache) {
@@ -118,7 +119,7 @@ public OkHttpClient buildAuthenticatedApiClient(
         OkHttpClient.Builder authenticatedApiClientBuilder = authServerApiClient.newBuilder();
 
         AccessTokenManager.AccessTokenManagerBuilder accessTokenManagerBuilder =
-                AccessTokenManager.builder().authenticationHandler(authenticationHandler);
+                AccessTokenManager.builder().clientId(clientId).authenticationHandler(authenticationHandler);
 
         // setup credentials caching if required
         if (isNotEmpty(credentialsCache)) {

src/main/java/com/truelayer/java/http/auth/AccessTokenManager.java

@@ -4,6 +4,7 @@
 import com.truelayer.java.auth.IAuthenticationHandler;
 import com.truelayer.java.auth.entities.AccessToken;
 import com.truelayer.java.entities.RequestScopes;
+import com.truelayer.java.http.auth.cache.CredentialsCacheHelper;
 import com.truelayer.java.http.auth.cache.ICredentialsCache;
 import com.truelayer.java.http.entities.ApiResponse;
 import java.util.Optional;
@@ -13,6 +14,8 @@
 @Builder
 public class AccessTokenManager implements IAccessTokenManager {
 
+    private final String clientId;
+
     private final IAuthenticationHandler authenticationHandler;
 
     private final ICredentialsCache credentialsCache;
@@ -23,10 +26,12 @@ private Optional<ICredentialsCache> getCredentialsCache() {
 
     @Override
     public AccessToken getToken(RequestScopes scopes) {
+        String cacheKey = CredentialsCacheHelper.buildKey(clientId, scopes);
+
         if (getCredentialsCache().isPresent()) {
-            return getCredentialsCache().get().getToken(scopes).orElseGet(() -> {
+            return getCredentialsCache().get().getToken(cacheKey).orElseGet(() -> {
                 AccessToken token = tryGetToken(scopes);
-                credentialsCache.storeToken(scopes, token);
+                credentialsCache.storeToken(cacheKey, token);
                 return token;
             });
         }
@@ -37,7 +42,8 @@ public AccessToken getToken(RequestScopes scopes) {
     @Override
     @Synchronized
     public void invalidateToken(RequestScopes scopes) {
-        getCredentialsCache().ifPresent(iCredentialsCache -> iCredentialsCache.clearToken(scopes));
+        String cacheKey = CredentialsCacheHelper.buildKey(clientId, scopes);
+        getCredentialsCache().ifPresent(iCredentialsCache -> iCredentialsCache.clearToken(cacheKey));
     }
 
     private AccessToken tryGetToken(RequestScopes scopes) {

src/main/java/com/truelayer/java/http/auth/cache/CredentialsCacheHelper.java

@@ -0,0 +1,50 @@
+package com.truelayer.java.http.auth.cache;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.apache.commons.lang3.ObjectUtils.isEmpty;
+
+import com.truelayer.java.TrueLayerException;
+import com.truelayer.java.entities.RequestScopes;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class CredentialsCacheHelper {
+    private static final String CACHE_KEY_PREFIX = "tl-auth-token";
+    private static final String SCOPES_DELIMITER = ",";
+
+    public static String buildKey(String clientId, RequestScopes requestScopes) {
+        if (isEmpty(clientId) || isEmpty(requestScopes) || isEmpty(requestScopes.getScopes())) {
+            throw new TrueLayerException("Invalid client id or request scopes provided");
+        }
+
+        List<String> scopes = new ArrayList<>(requestScopes.getScopes());
+
+        // Use natural ordering to make ordering not significant
+        Collections.sort(scopes);
+
+        byte[] md5InBytes = digest(String.join(SCOPES_DELIMITER, scopes).getBytes(UTF_8));
+        return MessageFormat.format("{0}:{1}:{2}", CACHE_KEY_PREFIX, clientId, bytesToHex(md5InBytes));
+    }
+
+    private static byte[] digest(byte[] input) {
+        MessageDigest md;
+        try {
+            md = MessageDigest.getInstance("MD5");
+        } catch (NoSuchAlgorithmException e) {
+            throw new TrueLayerException("Hashing algorithm is not available", e);
+        }
+        return md.digest(input);
+    }
+
+    private static String bytesToHex(byte[] bytes) {
+        StringBuilder sb = new StringBuilder();
+        for (byte b : bytes) {
+            sb.append(String.format("%02x", b));
+        }
+        return sb.toString();
+    }
+}

src/main/java/com/truelayer/java/http/auth/cache/ICredentialsCache.java

@@ -1,28 +1,13 @@
 package com.truelayer.java.http.auth.cache;
 
 import com.truelayer.java.auth.entities.AccessToken;
-import com.truelayer.java.entities.RequestScopes;
 import java.util.Optional;
 
 public interface ICredentialsCache {
 
-    /**
-     * Gets the cached access token for the given request scopes.
-     * @param scopes the requested scopes
-     * @return an optional access token. If the token is expired an empty optional is returned
-     */
-    Optional<AccessToken> getToken(RequestScopes scopes);
+    Optional<AccessToken> getToken(String key);
 
-    /**
-     * Stores an access token in cache for the given request scopes.
-     * @param token the new token to store
-     * @param scopes the requested scopes
-     */
-    void storeToken(RequestScopes scopes, AccessToken token);
+    void storeToken(String key, AccessToken token);
 
-    /**
-     * Remove the entry in the cache for the given request scopes.
-     * @param scopes the requested scopes
-     */
-    void clearToken(RequestScopes scopes);
+    void clearToken(String key);
 }