Implement very basic HTTP client in 1.20

fabric/src/main/java/net/smyler/terramap/TerramapFabricMod.java

@@ -9,6 +9,7 @@
 import net.smyler.smylib.json.TextJsonAdapter;
 import net.smyler.smylib.text.Text;
 import net.smyler.terramap.http.HttpClient;
+import net.smyler.terramap.http.TerramapHttpClient;
 import org.apache.logging.log4j.Logger;
 
 import static org.apache.logging.log4j.LogManager.getLogger;
@@ -23,11 +24,12 @@ public class TerramapFabricMod implements ModInitializer, Terramap {
             .registerTypeAdapter(Text.class, new TextJsonAdapter())
             .setPrettyPrinting()
             .create();
+    private final HttpClient httpClient = new TerramapHttpClient(this.logger);
 
     @Override
     public void onInitialize() {
-        Terramap.InstanceHolder.setInstance(this);
         this.logger.info("Initializing Terramap");
+        Terramap.InstanceHolder.setInstance(this);
         SmyLib.initializeGameClient(new WrappedMinecraft(Minecraft.getInstance()), this.logger);
     }
 
@@ -38,7 +40,7 @@ public Logger logger() {
 
     @Override
     public HttpClient http() {
-        return null;
+        return this.httpClient;
     }
 
     @Override

fabric/src/main/java/net/smyler/terramap/http/TerramapHttpClient.java

@@ -0,0 +1,60 @@
+package net.smyler.terramap.http;
+
+import org.apache.logging.log4j.Logger;
+
+import java.net.URI;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.Objects;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.CompletableFuture;
+
+
+public class TerramapHttpClient implements HttpClient {
+
+    private static final String USER_AGENT = "Experimental Terramap version https://github.com/SmylerMC/terramap";
+    private final java.net.http.HttpClient client = java.net.http.HttpClient.newBuilder().build();
+    private final Logger logger;
+
+    public TerramapHttpClient(Logger logger) {
+        this.logger = logger;
+        logger.warn("You are using an HTTP client that does not support caching. This is not suitable for production.");
+    }
+
+    @Override
+    public CompletableFuture<byte[]> get(String url) {
+        HttpRequest request = HttpRequest.newBuilder()
+                .uri(URI.create(url))
+                .header("User-Agent", USER_AGENT)
+                .GET()
+                .build();
+        this.log(request);
+        CompletableFuture<HttpResponse<byte[]>> response = this.client.sendAsync(request, HttpResponse.BodyHandlers.ofByteArray());
+        CompletableFuture<byte[]> bytes = response.thenApply(HttpResponse::body);
+        bytes.exceptionally(t -> {
+            if (t instanceof CancellationException) {
+                response.cancel(true);
+            }
+            return null;
+        });
+        return bytes;
+    }
+
+    @Override
+    public void setMaxConcurrentRequests(String host, int maxConcurrentRequests) {
+        logger.warn(
+                "Trying to set max concurrent requests to {}: {}. This is not yet supported",
+                host,
+                maxConcurrentRequests
+        );
+    }
+
+    private void log(HttpRequest request) {
+        this.logger.debug("{} {} {}",
+                request.method(),
+                request.uri(),
+                request.version().map(Objects::toString).orElse("")
+        );
+    }
+
+}