add hex as required dependency, then use it inside init_blocks_table

Cargo.toml

@@ -14,7 +14,7 @@ android_logger = "0.6"
 failure = "0.1"
 futures = { version = "0.1", optional = true }
 grpc = { version = "0.6", optional = true }
-hex = { version = "0.3", optional = true }
+hex = "0.3"
 jni = { version = "0.10", default-features = false }
 log = "0.4"
 log-panics = "2.0.0"
@@ -52,7 +52,7 @@ dirs = "1"
 tempfile = "3"
 
 [features]
-updater = ["futures", "grpc", "hex"]
+updater = ["futures", "grpc"]
 
 [lib]
 name = "zcashwalletsdk"

src/main/java/cash/z/wallet/sdk/jni/JniConverter.kt

@@ -13,7 +13,7 @@ class JniConverter {
         dbData: String,
         height: Int,
         time: Long,
-        saplingTree: ByteArray): Boolean
+        saplingTree: String): Boolean
 
     external fun getAddress(dbData: String, account: Int): String
 

src/main/rust/bin/update_sapling_tree.rs

@@ -26,11 +26,11 @@ const BATCH_SIZE: u64 = 10_000;
 fn print_sapling_tree(height: u64, time: u32, tree: CommitmentTree) {
     let mut tree_bytes = vec![];
     tree.write(&mut tree_bytes).unwrap();
-    println!("{");
+    println!("{{");
     println!("  \"height\": {},", height);
     println!("  \"time\": {},", time);
     println!("  \"tree\": \"{}\",", hex::encode(tree_bytes));
-    println!("}");
+    println!("}}");
 }
 
 fn main() {

src/main/rust/lib.rs

@@ -1,5 +1,6 @@
 #[macro_use]
 extern crate log;
+extern crate hex;
 
 mod sql;
 mod utils;
@@ -119,7 +120,7 @@ pub unsafe extern "C" fn Java_cash_z_wallet_sdk_jni_JniConverter_initBlocksTable
     db_data: JString<'_>,
     height: jint,
     time: jlong,
-    sapling_tree: jbyteArray,
+    sapling_tree_string: JString<'_>,
 ) -> jboolean {
     let res = panic::catch_unwind(|| {
         let db_data = utils::java_string_to_rust(&env, db_data);
@@ -128,7 +129,8 @@ pub unsafe extern "C" fn Java_cash_z_wallet_sdk_jni_JniConverter_initBlocksTable
         } else {
             return Err(format_err!("time argument must fit in a u32"));
         };
-        let sapling_tree = env.convert_byte_array(sapling_tree).unwrap();
+        let sapling_tree =
+            hex::decode(utils::java_string_to_rust(&env, sapling_tree_string)).unwrap();
 
         match init_blocks_table(&db_data, height, time, &sapling_tree) {
             Ok(()) => Ok(JNI_TRUE),