Streaming output for Helidon/Javalin

http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/nima/ControllerMethodWriter.java

@@ -17,6 +17,7 @@
  */
 final class ControllerMethodWriter {
 
+  private static final String FILTER_CHAIN = "FilterChain";
   private static final Map<Integer,String> statusMap = new HashMap<>();
   static {
     statusMap.put(200, "OK_200");
@@ -78,7 +79,7 @@ final class ControllerMethodWriter {
   }
 
   private void validateMethod() {
-    if (method.params().stream().map(MethodParam::shortType).noneMatch("FilterChain"::equals)) {
+    if (method.params().stream().map(MethodParam::shortType).noneMatch(FILTER_CHAIN::equals)) {
       logError(method.element(), "Filters must contain a FilterChain Parameter");
     }
   }
@@ -223,7 +224,7 @@ void writeHandler(boolean requestScoped) {
       final var param = params.get(i);
       if (isAssignable2Interface(param.utype().mainType(), "java.lang.Exception")) {
         writer.append("ex");
-      } else if ("FilterChain".equals(param.shortType())) {
+      } else if (FILTER_CHAIN.equals(param.shortType())) {
         writer.append("chain");
       } else {
         param.buildParamName(writer);
@@ -242,34 +243,42 @@ void writeHandler(boolean requestScoped) {
         writer.append("      res.status(NO_CONTENT_204).send();").eol();
         writer.append("    } else {").eol();
       }
+      final var uType = UType.parse(method.returnType());
       String indent = includeNoContent ? "      " : "    ";
-      if (responseMode == ResponseMode.Templating) {
-        writer.append(indent).append("var content = renderer.render(result);").eol();
-        if (withContentCache) {
-          writer.append(indent).append("contentCache.contentPut(key, content);").eol();
-        }
-        writeContextReturn(indent);
-        writer.append(indent).append("res.send(content);").eol();
+      switch (responseMode) {
+        case ResponseMode.Templating -> {
+          writer.append(indent).append("var content = renderer.render(result);").eol();
+          if (withContentCache) {
+            writer.append(indent).append("contentCache.contentPut(key, content);").eol();
+          }
+          writeContextReturn(indent);
+          writer.append(indent).append("res.send(content);").eol();
 
-      } else if (responseMode == ResponseMode.Jstachio) {
-        var renderer = ProcessingContext.jstacheRenderer(method.returnType());
-        writer.append(indent).append("var content = %s(result);", renderer).eol();
-        writeContextReturn(indent);
-        writer.append(indent).append("res.send(content);").eol();
+        }
+        case ResponseMode.Jstachio -> {
+          var renderer = ProcessingContext.jstacheRenderer(method.returnType());
+          writer.append(indent).append("var content = %s(result);", renderer).eol();
+          writeContextReturn(indent);
+          writer.append(indent).append("res.send(content);").eol();
 
-      } else {
-        final var uType = UType.parse(method.returnType());
-        writeContextReturn(indent, streamingResponse(uType));
-        if (responseMode == ResponseMode.InputStream) {
-          writer.append(indent).append("result.transferTo(res.outputStream());", uType.shortName()).eol();
-        } else if (responseMode == ResponseMode.Json) {
-          if (returnTypeString()) {
-            writer.append(indent).append("res.send(result); // send raw JSON").eol();
+        }
+        case ResponseMode.StreamingOutput -> {
+          writeContextReturn(indent, streamingResponse(uType));
+          writeStreamingOutputReturn(indent);
+        }
+        default -> {
+          writeContextReturn(indent, streamingResponse(uType));
+          if (responseMode == ResponseMode.InputStream) {
+            writer.append(indent).append("result.transferTo(res.outputStream());", uType.shortName()).eol();
+          } else if (responseMode == ResponseMode.Json) {
+            if (returnTypeString()) {
+              writer.append(indent).append("res.send(result); // send raw JSON").eol();
+            } else {
+              writer.append(indent).append("%sJsonType.toJson(result, JsonOutput.of(res));", uType.shortName()).eol();
+            }
           } else {
-            writer.append(indent).append("%sJsonType.toJson(result, JsonOutput.of(res));", uType.shortName()).eol();
+            writer.append(indent).append("res.send(result);").eol();
           }
-        } else {
-          writer.append(indent).append("res.send(result);").eol();
         }
       }
       if (includeNoContent) {
@@ -279,8 +288,14 @@ void writeHandler(boolean requestScoped) {
     writer.append("  }").eol().eol();
   }
 
+  private void writeStreamingOutputReturn(String indent) {
+    writer.append(indent).append("try (var responseOutputStream = res.outputStream()) {").eol();
+    writer.append(indent).append(indent).append("result.write(responseOutputStream);").eol();
+    writer.append(indent).append("}").eol();
+  }
+
   private static boolean streamingResponse(UType uType) {
-    return uType.mainType().equals("java.util.stream.Stream");
+    return "java.util.stream.Stream".equals(uType.mainType());
   }
 
   enum ResponseMode {
@@ -289,6 +304,7 @@ enum ResponseMode {
     Jstachio,
     Templating,
     InputStream,
+    StreamingOutput,
     Other
   }
 
@@ -299,6 +315,9 @@ ResponseMode responseMode() {
     if (isInputStream(method.returnType())) {
       return ResponseMode.InputStream;
     }
+    if (isStreamingOutput(method.returnType())) {
+      return ResponseMode.StreamingOutput;
+    }
     if (producesJson()) {
       return ResponseMode.Json;
     }
@@ -323,7 +342,7 @@ private boolean useTemplating() {
 
   private static boolean isExceptionOrFilterChain(MethodParam param) {
     return isAssignable2Interface(param.utype().mainType(), "java.lang.Exception")
-      || "FilterChain".equals(param.shortType());
+      || FILTER_CHAIN.equals(param.shortType());
   }
 
   private boolean isInputStream(TypeMirror type) {
@@ -420,4 +439,8 @@ private String lookupStatusCode(int statusCode) {
   public void buildApiDocumentation() {
     method.buildApiDoc();
   }
+
+  private boolean isStreamingOutput(TypeMirror type) {
+    return isAssignable2Interface(type.toString(), "io.avaje.http.api.StreamingOutput");
+  }
 }

http-generator-javalin/src/main/java/io/avaje/http/generator/javalin/ControllerMethodWriter.java

@@ -159,10 +159,19 @@ private void writeContextReturn(final String resultVariableName) {
       produces = MediaType.TEXT_HTML.getValue();
     }
 
+    var uType = UType.parse(method.returnType());
+
     boolean applicationJson = produces == null || MediaType.APPLICATION_JSON.getValue().equalsIgnoreCase(produces);
-    if (applicationJson || JsonBUtil.isJsonMimeType(produces)) {
+
+    if (isAssignable2Interface(uType.mainType(), "io.avaje.http.api.StreamingOutput")) {
+      writer.append("      ctx.contentType(\"%s\");", produces).eol();
+      writer.append("      try (var ctxOutputStream = ctx.outputStream()) {").eol();
+      writer.append("            %s.write(ctxOutputStream);", resultVariableName).eol();
+      writer.append("      } catch (java.io.IOException e) {").eol();
+      writer.append("            throw new java.io.UncheckedIOException(e);").eol();
+      writer.append("      }").eol();
+    } else if (applicationJson || JsonBUtil.isJsonMimeType(produces)) {
       if (useJsonB) {
-        var uType = UType.parse(method.returnType());
         final boolean isfuture = "java.util.concurrent.CompletableFuture".equals(uType.mainType());
         if (isfuture || method.isErrorMethod()) {
           if (isfuture) {

http-generator-jex/src/main/java/io/avaje/http/generator/jex/ControllerMethodWriter.java

@@ -310,9 +310,9 @@ private void writeContextReturn(ResponseMode responseMode, String resultVariable
 
   private void writeStreamingOutputReturn(String produces, String resultVariable, String indent) {
     writer.append("ctx.contentType(\"%s\");", produces).eol();
-    writer.append(indent).append("try (java.io.OutputStream ctxOutputStream = ctx.outputStream()) {").eol();
+    writer.append(indent).append("try (var ctxOutputStream = ctx.outputStream()) {").eol();
     writer.append(indent).append(indent).append("%s.write(ctxOutputStream);", resultVariable).eol();
-    writer.append(indent).append("}", resultVariable);
+    writer.append(indent).append("}");
   }
 
   private void writeJsonReturn(String produces, String indent) {
@@ -340,7 +340,7 @@ private void writeJsonReturn(String produces, String indent) {
   }
 
   private static boolean streamingContent(UType uType) {
-    return uType.mainType().equals("java.util.stream.Stream");
+    return "java.util.stream.Stream".equals(uType.mainType());
   }
 
   private static boolean isExceptionOrFilterChain(MethodParam param) {

tests/test-javalin-jsonb/src/main/java/org/example/myapp/web/HelloController.java

@@ -9,6 +9,7 @@
 import java.util.concurrent.Executors;
 
 import org.example.myapp.service.MyService;
+import org.example.myapp.web.other.Foo;
 
 import io.avaje.http.api.BeanParam;
 import io.avaje.http.api.Controller;
@@ -21,11 +22,11 @@
 import io.avaje.http.api.Post;
 import io.avaje.http.api.Produces;
 import io.avaje.http.api.QueryParam;
+import io.avaje.http.api.StreamingOutput;
 import io.avaje.http.api.Valid;
 import io.javalin.http.Context;
 import io.swagger.v3.oas.annotations.Hidden;
 import jakarta.inject.Inject;
-import org.example.myapp.web.other.Foo;
 
 /**
  * Hello resource manager.
@@ -152,7 +153,7 @@ CompletableFuture<List<HelloDto>> getAllAsync() {
       // This also helps ensure that we aren't just getting lucky with timings.
       try {
         Thread.sleep(10L);
-      } catch (InterruptedException e) {
+      } catch (final InterruptedException e) {
         throw new RuntimeException(e);
       }
 
@@ -190,4 +191,12 @@ String controlStatusCode(Context ctx) {
   String takesNestedEnum(Foo.NestedEnum myEnum) {
     return "takesNestedEnum-" + myEnum;
   }
+
+  @Get("streamBytes")
+  @Produces(value = "text/html", statusCode = 200)
+  StreamingOutput streamBytes() {
+    return outputStream -> outputStream.write(new byte[]{
+      0x41, 0x76, 0x61, 0x6a, 0x65
+    });
+  }
 }

tests/test-javalin-jsonb/src/main/resources/public/openapi.json

@@ -678,6 +678,27 @@
 				}
 			}
 		},
+		"/hello/streamBytes" : {
+			"get" : {
+				"tags" : [
+
+				],
+				"summary" : "",
+				"description" : "",
+				"responses" : {
+					"200" : {
+						"description" : "",
+						"content" : {
+							"text/html" : {
+								"schema" : {
+									"$ref" : "#/components/schemas/StreamingOutput"
+								}
+							}
+						}
+					}
+				}
+			}
+		},
 		"/hello/takesNestedEnum" : {
 			"get" : {
 				"tags" : [
@@ -2357,6 +2378,9 @@
 					}
 				}
 			},
+			"StreamingOutput" : {
+				"type" : "object"
+			},
 			"String,?>" : {
 				"type" : "object"
 			},

tests/test-javalin-jsonb/src/test/java/org/example/myapp/HelloControllerTest.java

@@ -1,23 +1,28 @@
 package org.example.myapp;
 
-import io.avaje.http.client.*;
-import io.restassured.common.mapper.TypeRef;
-import io.restassured.http.ContentType;
-import io.restassured.response.Response;
-import org.example.myapp.web.HelloDto;
-import org.junit.jupiter.api.Test;
-
-import java.net.http.HttpResponse;
-import java.util.List;
-import java.util.Map;
-
 import static io.restassured.RestAssured.get;
 import static io.restassured.RestAssured.given;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
+import java.net.http.HttpResponse;
+import java.util.List;
+import java.util.Optional;
+
+import org.example.myapp.web.HelloDto;
+import org.junit.jupiter.api.Test;
+
+import io.avaje.http.client.BodyReader;
+import io.avaje.http.client.BodyWriter;
+import io.avaje.http.client.HttpClient;
+import io.avaje.http.client.HttpException;
+import io.avaje.http.client.JacksonBodyAdapter;
+import io.restassured.common.mapper.TypeRef;
+import io.restassured.http.ContentType;
+import io.restassured.response.Response;
+
 class HelloControllerTest extends BaseWebTest {
 
   final HttpClient client;
@@ -45,7 +50,7 @@ void hello() {
   @Test
   void hello2() {
 
-    TypeRef<List<HelloDto>> listDto = new TypeRef<>() { };
+    final TypeRef<List<HelloDto>> listDto = new TypeRef<>() { };
     final List<HelloDto> beans = given()
       .get(baseUrl + "/hello")
       .then()
@@ -64,7 +69,7 @@ void hello2() {
 
   @Test
   void helloAsyncRequestHandling() {
-    TypeRef<List<HelloDto>> listDto = new TypeRef<>() { };
+    final TypeRef<List<HelloDto>> listDto = new TypeRef<>() { };
     final List<HelloDto> beans = given()
       .get(baseUrl + "/hello/async")
       .then()
@@ -106,7 +111,7 @@ void getWithPathParamAndQueryParam() {
 
   @Test
   void postIt() {
-    HelloDto dto = new HelloDto(12, "rob", "other");
+    final HelloDto dto = new HelloDto(12, "rob", "other");
 
     given().body(dto).post(baseUrl + "/hello")
       .then()
@@ -129,7 +134,7 @@ void postIt() {
 
   @Test
   void saveBean() {
-    HelloDto dto = new HelloDto(12, "rob", "other");
+    final HelloDto dto = new HelloDto(12, "rob", "other");
 
     given().body(dto).post(baseUrl + "/hello/savebean/foo")
       .then()
@@ -217,7 +222,7 @@ void postForm_validation_expect_badRequest() {
         .POST()
         .asVoid();
 
-    } catch (HttpException e) {
+    } catch (final HttpException e) {
       assertEquals(422, e.statusCode());
 
       final HttpResponse<?> httpResponse = e.httpResponse();
@@ -331,4 +336,18 @@ void get_controlStatusCode_expect201() {
     assertEquals("controlStatusCode", hres.body());
   }
 
+  @Test
+  void streamBytesTest() {
+    final HttpResponse<String> res = client.request()
+      .path("hello/streamBytes")
+      .GET()
+      .asString();
+
+    final Optional<String> contentTypeHeaderValueOptional = res.headers().firstValue("Content-Type");
+
+    assertThat(contentTypeHeaderValueOptional.isPresent()).isEqualTo(true);
+   // assertThat(contentTypeHeaderValueOptional.get()).isEqualTo("text/html");
+    assertThat(res.body()).isEqualTo("Avaje");
+    assertThat(res.statusCode()).isEqualTo(200);
+  }
 }

tests/test-nima-jsonb/src/main/java/org/example/HelloController.java

@@ -15,6 +15,7 @@
 import io.avaje.http.api.Produces;
 import io.avaje.http.api.Put;
 import io.avaje.http.api.QueryParam;
+import io.avaje.http.api.StreamingOutput;
 import io.avaje.http.api.Valid;
 import io.helidon.common.media.type.MediaTypes;
 import io.helidon.webserver.http.ServerRequest;
@@ -164,4 +165,10 @@ String formBean(MyForm form) {
   String testBigInt(BigInteger val, BigInteger someQueryParam) {
     return "hi|" + val;
   }
+
+  @Get("streamBytes")
+  @Produces(value = "text/html", statusCode = 200)
+  StreamingOutput streamBytes() {
+    return outputStream -> outputStream.write(new byte[] {0x41, 0x76, 0x61, 0x6a, 0x65});
+  }
 }