Add missing JsonRpcTransport from previous commit

consensusj-jsonrpc/src/main/java/org/consensusj/jsonrpc/JsonRpcTransport.java

@@ -0,0 +1,104 @@
+package org.consensusj.jsonrpc;
+
+import javax.net.ssl.SSLContext;
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.net.URI;
+import java.security.NoSuchAlgorithmException;
+import java.util.Base64;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.function.Supplier;
+
+// TODO: Have JsonRpcClientJavaNet and JsonRpcClientHttpUrlConnection directly implement this class
+// and AbstractRpcClient become DefaultRpcClient and take a transport instance in its constructor.
+/**
+ * Defines the interface for a network-layer implementation of a JSON-RPC client.
+ */
+public interface JsonRpcTransport<T extends Type> extends AsyncSupport {
+    /**
+     * Get the URI of the remote server
+     * @return URI of remote server
+     */
+    URI getServerURI();
+
+    /**
+     * Send a {@link JsonRpcRequest} for a {@link JsonRpcResponse}
+     * <p>Synchronous subclasses should override this method to prevent {@link CompletableFuture#supplyAsync(Supplier)} from
+     * being called twice when {@link AsyncSupport} is being used. Eventually we'll migrate more of the codebase to native
+     * async, and then we won't have to worry about calling {@code supplyAsync} twice.
+     * @param <R> Type of result object
+     * @param request The request to send
+     * @param responseType The response type expected (used by Jackson for conversion)
+     * @return A JSON RPC Response with `result` of type `R`
+     * @throws IOException network error
+     * @throws JsonRpcStatusException JSON RPC status error
+     */
+    default <R> JsonRpcResponse<R> sendRequestForResponse(JsonRpcRequest request, T responseType) throws IOException, JsonRpcStatusException {
+        return syncGet(sendRequestForResponseAsync(request, responseType));
+    }
+
+    /**
+     * Send a {@link JsonRpcRequest} for a {@link JsonRpcResponse} asynchronously.
+     * @param <R> Type of result object
+     * @param request The request to send
+     * @param responseType The response type expected (used by Jackson for conversion)
+     * @return A future JSON RPC Response with `result` of type `R`
+     */
+    <R> CompletableFuture<JsonRpcResponse<R>> sendRequestForResponseAsync(JsonRpcRequest request, T responseType);
+
+    /**
+     * Synchronously complete a JSON-RPC request by calling {@link CompletableFuture#get()}, unwrapping nested
+     * {@link JsonRpcException} or {@link IOException} from {@link ExecutionException}.
+     * @param future The {@code CompletableFuture} (result of JSON-RPC request) to unwrap
+     * @return A JSON-RPC result
+     * @param <R> The expected result type
+     * @throws IOException If {@link CompletableFuture#get} threw  {@code ExecutionException} caused by {@code IOException}
+     * @throws JsonRpcException If {@link CompletableFuture#get} threw  {@code ExecutionException} caused by {@code JsonRpcException}
+     * @throws RuntimeException If {@link CompletableFuture#get} threw {@link InterruptedException} or other {@link ExecutionException}.
+     */
+    default <R> R syncGet(CompletableFuture<R> future) throws IOException, JsonRpcException {
+        try {
+            return future.get();
+        } catch (InterruptedException ie) {
+            throw new RuntimeException(ie);
+        } catch (ExecutionException ee) {
+            Throwable cause = ee.getCause();
+            if (cause instanceof JsonRpcException) {
+                throw (JsonRpcException) cause;
+            } else if (cause instanceof IOException) {
+                throw (IOException) cause;
+            } else {
+                throw new RuntimeException(ee);
+            }
+        }
+    }
+
+
+
+    /**
+     * Encode username password as Base64 for basic authentication
+     * <p>
+     * We're using {@link java.util.Base64}, which requires Android 8.0 or later.
+     *
+     * @param authString An authorization string of the form `username:password`
+     * @return A compliant Base64 encoding of `authString`
+     */
+    static String base64Encode(String authString) {
+        return Base64.getEncoder().encodeToString(authString.getBytes()).trim();
+    }
+
+    /**
+     *
+     * Return the default {@link SSLContext} without declaring a checked exception
+     * @return The default {@code SSLContext}
+     */
+    static SSLContext getDefaultSSLContext() {
+        try {
+            return SSLContext.getDefault();
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+}