Merge pull request #48 from wching/kotlin_migration

Kotlin and JUnit Migration

library/build.gradle

@@ -1,10 +1,17 @@
+apply plugin: 'kotlin'
 apply plugin: 'groovy'
 apply plugin: 'maven'
 
 buildscript {
+    ext.kotlin_version = '1.3.41'
+
     repositories {
         mavenCentral()
     }
+
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
 }
 
 jar.archiveName = "Heimdall.Droid.jar"
@@ -17,17 +24,34 @@ repositories {
 }
 
 dependencies {
+    // Kotlin
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
 
     // Rx
-    implementation 'io.reactivex.rxjava2:rxjava:2.2.7'
+    implementation 'io.reactivex.rxjava2:rxjava:2.2.8'
 
     // GSON
     implementation 'com.google.code.gson:gson:2.8.5'
 
     // Testing
-    testImplementation "cglib:cglib:2.2"
     testImplementation 'junit:junit:4.12'
+    testImplementation 'org.mockito:mockito-core:2.27.0'
+    testImplementation "com.nhaarman.mockitokotlin2:mockito-kotlin:2.1.0"
+
+    testImplementation "cglib:cglib:2.2"
     testImplementation('org.spockframework:spock-core:1.0-groovy-2.4') {
         exclude group: 'junit'
     }
 }
+
+compileKotlin {
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}
+
+compileTestKotlin {
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}

library/src/main/java/de/rheinfabrik/heimdall2/OAuth2AccessToken.kt

@@ -0,0 +1,76 @@
+package de.rheinfabrik.heimdall2
+
+import com.google.gson.annotations.SerializedName
+import java.io.Serializable
+import java.util.Calendar
+
+class OAuth2AccessToken(
+    /**
+     * REQUIRED
+     * The type of the token issued as described in https://tools.ietf.org/html/rfc6749#section-7.1.
+     * Value is case insensitive.
+     */
+    @SerializedName("token_type")
+    var tokenType: String? = null,
+
+    /**
+     * REQUIRED
+     * The access token issued by the authorization server.
+     */
+    @SerializedName("access_token")
+    var accessToken: String? = null,
+
+    /**
+     * OPTIONAL
+     * The refresh token, which can be used to obtain new
+     * access tokens using the same authorization grant as described
+     * in https://tools.ietf.org/html/rfc6749#section-6.
+     */
+    @SerializedName("refresh_token")
+    var refreshToken: String? = null,
+
+    /**
+     * RECOMMENDED
+     * The lifetime in seconds of the access token.  For
+     * example, the value "3600" denotes that the access token will
+     * expire in one hour from the time the response was generated.
+     * If omitted, the authorization server SHOULD provide the
+     * expiration time via other means or document the default value.
+     */
+    @SerializedName("expires_in")
+    var expiresIn: Int? = null,
+
+    /**
+     * The expiration date used by Heimdall.
+     */
+    @SerializedName("heimdall_expiration_date")
+    var expirationDate: Calendar? = null
+) : Serializable {
+
+    // Public API
+
+    /**
+     * Returns whether the access token expired or not.
+     *
+     * @return True if expired. Otherwise false.
+     */
+    fun isExpired(): Boolean =
+        expirationDate != null &&
+            Calendar.getInstance().after(expirationDate)
+
+
+    override fun equals(other: Any?): Boolean =
+        when {
+            this === other -> true
+            other !is OAuth2AccessToken -> false
+            else -> {
+                accessToken.equals(other.accessToken) && tokenType.equals(other.accessToken)
+            }
+        }
+
+
+    override fun hashCode(): Int =
+        tokenType.hashCode().let {
+            31 * it + accessToken.hashCode()
+        }
+}

library/src/main/java/de/rheinfabrik/heimdall2/OAuth2AccessTokenManager.kt

@@ -0,0 +1,60 @@
+package de.rheinfabrik.heimdall2
+
+import de.rheinfabrik.heimdall2.grants.OAuth2Grant
+import de.rheinfabrik.heimdall2.grants.OAuth2RefreshAccessTokenGrant
+import io.reactivex.Single
+import java.util.Calendar
+
+open class OAuth2AccessTokenManager(
+    private val mStorage: OAuth2AccessTokenStorage
+) {
+
+    // Public API
+
+    /**
+     * Returns the underlying storage.
+     *
+     * @return - An OAuth2AccessTokenStorage.
+     */
+    fun getStorage(): OAuth2AccessTokenStorage = mStorage
+
+    /**
+     * Grants a new access token using the given OAuth2 grant.
+     *
+     * @param grant A class implementing the OAuth2Grant interface.
+     * @return - An Single emitting the granted access token.
+     */
+    fun grantNewAccessToken(
+        grant: OAuth2Grant,
+        calendar: Calendar = Calendar.getInstance()
+    ): Single<OAuth2AccessToken> =
+        grant.grantNewAccessToken()
+            .doOnSuccess { token ->
+                token.expiresIn?.let {
+                    val newExpirationDate = (calendar.clone() as Calendar).apply {
+                        add(Calendar.SECOND, it)
+                    }
+                    token.expirationDate = newExpirationDate
+                }
+                mStorage.storeAccessToken(token)
+            }.cache()
+
+    /**
+     * Returns an Observable emitting an unexpired access token.
+     * NOTE: In order to work, Heimdall needs an access token which has a refresh_token and an
+     * expires_in field.
+     *
+     * @param refreshAccessTokenGrant The refresh grant that will be used if the access token is expired.
+     * @return - An Single emitting an unexpired access token.
+     */
+    fun getValidAccessToken(refreshAccessTokenGrant: OAuth2RefreshAccessTokenGrant): Single<OAuth2AccessToken> =
+        mStorage.getStoredAccessToken()
+            .flatMap { accessToken ->
+                if (accessToken.isExpired()) {
+                    refreshAccessTokenGrant.refreshToken = accessToken.refreshToken
+                    grantNewAccessToken(refreshAccessTokenGrant)
+                } else {
+                    Single.just(accessToken)
+                }
+            }
+}