Add block explorer tx as hex request using completeable future api

Signed-off-by: HenrikJannsen <boilingfrog@gmx.com>

core/src/main/java/bisq/core/provider/MempoolHttpClient.java

@@ -27,6 +27,8 @@ import javax.inject.Singleton;
 
 import java.io.IOException;
 
+import java.util.concurrent.CompletableFuture;
+
 import javax.annotation.Nullable;
 
 @Singleton
@@ -42,4 +44,18 @@ public class MempoolHttpClient extends HttpClientImpl {
         String api = "/" + txId;
         return get(api, "User-Agent", "bisq/" + Version.VERSION);
     }
+
+
+    public CompletableFuture<String> requestTxAsHex(String txId) {
+        super.shutDown(); // close any prior incomplete request
+
+        return CompletableFuture.supplyAsync(() -> {
+            String api = "/" + txId + "/hex";
+            try {
+                return get(api, "User-Agent", "bisq/" + Version.VERSION);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        });
+    }
 }

core/src/main/java/bisq/core/provider/mempool/MempoolRequest.java

@@ -34,6 +34,7 @@ import com.google.common.util.concurrent.SettableFuture;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
+import java.util.concurrent.CompletableFuture;
 
 import lombok.extern.slf4j.Slf4j;
 
@@ -66,12 +67,19 @@ public class MempoolRequest {
                 log.info("Received mempoolData of [{}] from provider", mempoolData);
                 mempoolServiceCallback.set(mempoolData);
             }
+
             public void onFailure(@NotNull Throwable throwable) {
                 mempoolServiceCallback.setException(throwable);
             }
         }, MoreExecutors.directExecutor());
     }
 
+
+    public CompletableFuture<String> requestTxAsHex(String txId) {
+        mempoolHttpClient.setBaseUrl(getRandomServiceAddress(txBroadcastServices));
+        return mempoolHttpClient.requestTxAsHex(txId);
+    }
+
     public boolean switchToAnotherProvider() {
         txBroadcastServices.remove(mempoolHttpClient.getBaseUrl());
         return txBroadcastServices.size() > 0;

core/src/main/java/bisq/core/provider/mempool/MempoolService.java

@@ -43,6 +43,7 @@ import com.google.common.util.concurrent.SettableFuture;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
 
 import lombok.Getter;
@@ -129,7 +130,12 @@ public class MempoolService {
         mempoolRequest.getTxStatus(future, txId);
     }
 
-    // ///////////////////////////
+    public CompletableFuture<String> requestTxAsHex(String txId) {
+        outstandingRequests++;
+        return new MempoolRequest(preferences, socks5ProxyProvider)
+                .requestTxAsHex(txId)
+                .whenComplete((result, throwable) -> outstandingRequests--);
+    }
 
     private void validateOfferMakerTx(MempoolRequest mempoolRequest,
                                       TxValidator txValidator,