Use alternate JSON client language header method (#83)

Author: dzou

google-cloud-graalvm-support/src/main/java/com/google/cloud/graalvm/features/substitutions/ApiClientVersionSubstitutions.java

@@ -17,9 +17,7 @@
 package com.google.cloud.graalvm.features.substitutions;
 
 import com.oracle.svm.core.annotate.Alias;
-import com.oracle.svm.core.annotate.RecomputeFieldValue;
-import com.oracle.svm.core.annotate.RecomputeFieldValue.CustomFieldValueTransformer;
-import com.oracle.svm.core.annotate.RecomputeFieldValue.Kind;
+import com.oracle.svm.core.annotate.Substitute;
 import com.oracle.svm.core.annotate.TargetClass;
 import java.util.function.BooleanSupplier;
 
@@ -33,33 +31,23 @@
 final class ApiClientVersionSubstitutions {
 
   @Alias
-  @RecomputeFieldValue(kind = Kind.Custom, declClass = ApiVersionTransformer.class)
-  private static String DEFAULT_VERSION;
+  private String versionString;
 
-  private ApiClientVersionSubstitutions() {
-  }
-
-  static class ApiVersionTransformer implements CustomFieldValueTransformer {
-
-    @Override
-    public Object transform(
-        jdk.vm.ci.meta.MetaAccessProvider metaAccess,
-        jdk.vm.ci.meta.ResolvedJavaField original,
-        jdk.vm.ci.meta.ResolvedJavaField annotated,
-        Object receiver,
-        Object originalValue) {
-      String originalHeader = (String) originalValue;
-      String[] tokens = originalHeader.split(" ");
+  @Substitute
+  public String toString() {
+    String[] tokens = versionString.split(" ");
 
-      if (tokens.length > 0 && tokens[0].startsWith("gl-java")) {
-        tokens[0] += "-graalvm";
-        return String.join(" ", tokens);
-      } else {
-        return originalValue;
-      }
+    if (tokens.length > 0 && tokens[0].startsWith("gl-java")) {
+      tokens[0] += "-graalvm";
+      return String.join(" ", tokens);
+    } else {
+      return versionString;
     }
   }
 
+  private ApiClientVersionSubstitutions() {
+  }
+
   static class OnlyIfInClassPath implements BooleanSupplier {
 
     @Override

google-cloud-graalvm-support/src/main/resources/META-INF/native-image/com.google.cloud/google-cloud-graalvm-support/native-image.properties

@@ -8,4 +8,5 @@ Args = -H:+AllowIncompleteClasspath --report-unsupported-elements-at-runtime \
     io.grpc.netty.shaded.io.netty.internal.tcnative.SSLPrivateKeyMethod,\
     io.grpc.netty.shaded.io.grpc.netty,\
     io.grpc.netty.shaded.io.netty.channel.epoll,\
-    io.grpc.netty.shaded.io.netty.channel.unix
+    io.grpc.netty.shaded.io.netty.channel.unix,\
+    com.google.api.client.googleapis.services.AbstractGoogleClientRequest$ApiClientVersion