Android library load fix (#706)

Author: sbSteveK

android/crt/src/main/java/software/amazon/awssdk/crt/android/CrtPlatformImpl.java

@@ -9,12 +9,47 @@
 import software.amazon.awssdk.crt.BuildConfig;
 import software.amazon.awssdk.crt.CrtPlatform;
 import software.amazon.awssdk.crt.utils.PackageInfo;
+import java.util.Locale;
 
 public class CrtPlatformImpl extends CrtPlatform {
     public String getOSIdentifier() {
         return "android";
     }
 
+    public String getArchIdentifier() {
+        return System.getProperty("os.arch");
+    }
+
+    private String normalize(String value) {
+        if (value == null) {
+            return "";
+        }
+        return value.toLowerCase(Locale.US).replaceAll("[^a-z0-9]+", "");
+    }
+
+    public String getResourcePath(String cRuntime, String libraryName) {
+        // Internal folder structure of Android aar libraries are different from jar libraries
+        String arch = normalize(System.getProperty("os.arch"));
+
+        if (arch.matches("^(x8664|amd64|ia32e|em64t|x64|x86_64)$")) {
+            arch = "x86_64";
+        } else if (arch.matches("^(x8632|x86|i[3-6]86|ia32|x32)$")) {
+            arch =  "x86";
+        } else if (arch.startsWith("armeabi")) {
+            if (arch.contains("v7")) {
+                arch =  "armeabi-v7a";
+            } else {
+                throw new RuntimeException("AWS CRT: architecture not supported on Android: " + arch);
+            }
+        } else if (arch.startsWith("arm64") || arch.startsWith("aarch64")) {
+            arch =  "arm64-v8a";
+        } else {
+            throw new RuntimeException("AWS CRT: architecture not supported on Android: " + arch);
+        }
+
+        return "/lib/" + arch + "/" + libraryName;
+    }
+
     public PackageInfo.Version getVersion() {
         return new PackageInfo.Version(BuildConfig.VERSION_NAME);
     }

src/main/java/software/amazon/awssdk/crt/CRT.java

@@ -308,6 +308,15 @@ private static void extractAndLoadLibrary(String path) {
 
             // open a stream to read the shared lib contents from this JAR
             String libResourcePath = "/" + os + "/" + getArchIdentifier() + "/" +  getCRuntime(os) + "/" + libraryName;
+            // Check whether there is a platform specific resource path to use
+            CrtPlatform platform = getPlatformImpl();
+            if (platform != null){
+                String platformLibResourcePath = platform.getResourcePath(getCRuntime(os), libraryName);
+                if (platformLibResourcePath != null){
+                    libResourcePath = platformLibResourcePath;
+                }
+            }
+
             try (InputStream in = CRT.class.getResourceAsStream(libResourcePath)) {
                 if (in == null) {
                     throw new IOException("Unable to open library in jar for AWS CRT: " + libResourcePath);
@@ -406,6 +415,7 @@ private static CrtPlatform findPlatformImpl() {
                 String.format("software.amazon.awssdk.crt.test.%s.CrtPlatformImpl", getOSIdentifier()),
                 // Search for android test impl specifically because getOSIdentifier will return "linux" on android
                 "software.amazon.awssdk.crt.test.android.CrtPlatformImpl",
+                "software.amazon.awssdk.crt.android.CrtPlatformImpl",
                 // Fall back to crt
                 String.format("software.amazon.awssdk.crt.%s.CrtPlatformImpl", getOSIdentifier()), };
         for (String platformImpl : platforms) {

src/main/java/software/amazon/awssdk/crt/CrtPlatform.java

@@ -29,6 +29,11 @@ public String getArchIdentifier() {
         return System.getProperty("os.arch");
     }
 
+    // Get the library resource path to load the JNI library
+    public String getResourcePath(String cRuntime, String libraryName) throws RuntimeException {
+        return null;
+    }
+
     // Called one and only one time during setup for testing
     public void setupOnce() {}