ADD: templates for code generation

lib/codegen/java/async_http_client.dart

@@ -6,4 +6,72 @@ import 'package:apidash/models/models.dart' show RequestModel;
 import 'package:apidash/consts.dart';
 
 class JavaAsyncHttpClientGen {
+  final String kTemplateStart = '''
+import org.asynchttpclient.*;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+public class Main {
+    public static void main(String[] args) {
+        try (AsyncHttpClient asyncHttpClient = Dsl.asyncHttpClient()) {
+''';
+
+  final String kTemplateUrl = '''
+            String url = "{{url}}";\n
+''';
+
+  final String kTemplateRequestCreation = '''
+            Request request = asyncHttpClient
+                .prepare("{{method}}", url)\n
+''';
+
+  final String kTemplateUrlQueryParam = '''
+                .addQueryParam("{{name}}", "{{value}}")\n
+''';
+
+  final String kTemplateRequestHeader = '''
+                .addHeader("{{name}}", "{{value}}")\n
+''';
+  final String kTemplateRequestFormData = '''
+                .addFormParam("{{name}}", "{{value}}")\n
+''';
+
+  String kTemplateRequestBodyContent = '''
+            String bodyContent = "{{body}}";\n
+''';
+  String kTemplateRequestBodySetup = '''
+                .setBody(bodyContent)\n
+''';
+
+  final String kTemplateRequestEnd = """
+                .build();
+            ListenableFuture<Response> listenableFuture = asyncHttpClient.executeRequest(request);
+            listenableFuture.addListener(() -> {
+                try {
+                    Response response = listenableFuture.get();
+                    InputStream is = response.getResponseBodyAsStream();
+                    BufferedReader br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));
+                    String respBody = br.lines().collect(Collectors.joining("\\n"));
+                    System.out.println(response.getStatusCode());
+                    System.out.println(respBody);
+                } catch (InterruptedException | ExecutionException e) {
+                    e.printStackTrace();
+                }
+            }, Executors.newCachedThreadPool());
+            listenableFuture.get();
+        } catch (InterruptedException | ExecutionException | IOException ignored) {
+
+        }
+    }
+}
+\n
+""";
+
 }