diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/HttpMessageWriterView.java b/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/HttpMessageWriterView.java index 60514a94ef..7e4108d182 100644 --- a/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/HttpMessageWriterView.java +++ b/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/HttpMessageWriterView.java @@ -1,5 +1,5 @@ /* - * Copyright 2002-2016 the original author or authors. + * Copyright 2002-2017 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -17,11 +17,12 @@ package org.springframework.web.reactive.result.view; import java.util.Collections; -import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; +import java.util.Optional; import java.util.Set; +import java.util.stream.Collectors; import org.reactivestreams.Publisher; import reactor.core.publisher.Mono; @@ -37,53 +38,65 @@ import org.springframework.web.server.ServerWebExchange; /** - * A {@link View} that delegates to an {@link HttpMessageWriter}. + * {@code View} that writes model attribute(s) with an {@link HttpMessageWriter}. * * @author Rossen Stoyanchev * @since 5.0 */ public class HttpMessageWriterView implements View { - private final HttpMessageWriter messageWriter; + private final HttpMessageWriter writer; private final Set modelKeys = new HashSet<>(4); - private final List mediaTypes; + private final boolean canWriteMap; /** - * Create a {@code View} with the given {@code Encoder} wrapping it as an - * {@link EncoderHttpMessageWriter}. + * Constructor with an {@code Encoder}. */ public HttpMessageWriterView(Encoder encoder) { this(new EncoderHttpMessageWriter<>(encoder)); } /** - * Create a View that delegates to the given message messageWriter. + * Constructor with a fully initialized {@link HttpMessageWriter}. */ - public HttpMessageWriterView(HttpMessageWriter messageWriter) { - Assert.notNull(messageWriter, "'messageWriter' is required."); - this.messageWriter = messageWriter; - this.mediaTypes = messageWriter.getWritableMediaTypes(); + public HttpMessageWriterView(HttpMessageWriter writer) { + Assert.notNull(writer, "'writer' is required."); + this.writer = writer; + this.canWriteMap = writer.canWrite(ResolvableType.forClass(Map.class), null); } /** - * Return the configured message messageWriter. + * Return the configured message writer. */ public HttpMessageWriter getMessageWriter() { - return this.messageWriter; + return this.writer; } /** - * By default model attributes are filtered with - * {@link HttpMessageWriter#canWrite} to find the ones that can be - * rendered. Use this property to further narrow the list and consider only - * attribute(s) under specific model key(s). - *

If more than one matching attribute is found, than a Map is rendered, - * or if the {@code Encoder} does not support rendering a {@code Map} then - * an exception is raised. + * {@inheritDoc} + *

The implementation of this method for {@link HttpMessageWriterView} + * delegates to {@link HttpMessageWriter#getWritableMediaTypes()}. + */ + @Override + public List getSupportedMediaTypes() { + return this.writer.getWritableMediaTypes(); + } + + /** + * Set the attributes in the model that should be rendered by this view. + * When set, all other model attributes will be ignored. The matching + * attributes are further narrowed with {@link HttpMessageWriter#canWrite}. + * The matching attributes are processed as follows: + *

*/ public void setModelKeys(Set modelKeys) { this.modelKeys.clear(); @@ -99,73 +112,50 @@ public class HttpMessageWriterView implements View { return this.modelKeys; } - @Override - public List getSupportedMediaTypes() { - return this.mediaTypes; - } @Override - public Mono render(Map model, MediaType contentType, - ServerWebExchange exchange) { - Object value = extractObjectToRender(model); - return applyMessageWriter(value, contentType, exchange); + @SuppressWarnings("unchecked") + public Mono render(Map model, MediaType contentType, ServerWebExchange exchange) { + return getObjectToRender(model) + .map(value -> { + Publisher stream = Mono.justOrEmpty(value); + ResolvableType type = ResolvableType.forClass(value.getClass()); + ServerHttpResponse response = exchange.getResponse(); + return this.writer.write(stream, type, contentType, response, Collections.emptyMap()); + }) + .orElseGet(() -> exchange.getResponse().setComplete()); } - protected Object extractObjectToRender(Map model) { - Map map = new HashMap<>(model.size()); - for (Map.Entry entry : model.entrySet()) { - if (isEligibleAttribute(entry.getKey(), entry.getValue())) { - map.put(entry.getKey(), entry.getValue()); - } + private Optional getObjectToRender(Map model) { + + Map result = model.entrySet().stream() + .filter(this::isMatch) + .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)); + + if (result.isEmpty()) { + return Optional.empty(); } - if (map.isEmpty()) { - return null; + else if (result.size() == 1) { + return Optional.of(result.values().iterator().next()); } - else if (map.size() == 1) { - return map.values().iterator().next(); - } - else if (getMessageWriter().canWrite(ResolvableType.forClass(Map.class), null)) { - return map; + else if (this.canWriteMap) { + return Optional.of(result); } else { - throw new IllegalStateException( - "Multiple matching attributes found: " + map + ". " + - "However Map rendering is not supported by " + getMessageWriter()); + throw new IllegalStateException("Multiple matches found: " + result + " but " + + "Map rendering is not supported by " + getMessageWriter().getClass().getName()); } } - /** - * Whether the given model attribute key-value pair is eligible for encoding. - *

The default implementation checks against the configured - * {@link #setModelKeys model keys} and whether the Encoder supports the - * value type. - */ - protected boolean isEligibleAttribute(String attributeName, Object attributeValue) { - ResolvableType type = ResolvableType.forClass(attributeValue.getClass()); - if (getModelKeys().isEmpty()) { - return getMessageWriter().canWrite(type, null); + private boolean isMatch(Map.Entry entry) { + if (entry.getValue() == null) { + return false; } - if (getModelKeys().contains(attributeName)) { - if (getMessageWriter().canWrite(type, null)) { - return true; - } - throw new IllegalStateException( - "Model object [" + attributeValue + "] retrieved via key " + - "[" + attributeName + "] is not supported by " + getMessageWriter()); + if (!getModelKeys().isEmpty() && !getModelKeys().contains(entry.getKey())) { + return false; } - return false; - } - - @SuppressWarnings("unchecked") - private Mono applyMessageWriter(Object value, MediaType contentType, ServerWebExchange exchange) { - if (value == null) { - return Mono.empty(); - } - Publisher stream = Mono.just((T) value); - ResolvableType type = ResolvableType.forClass(value.getClass()); - ServerHttpResponse response = exchange.getResponse(); - return ((HttpMessageWriter) getMessageWriter()).write(stream, type, contentType, - response, Collections.emptyMap()); + ResolvableType type = ResolvableType.forInstance(entry.getValue()); + return getMessageWriter().canWrite(type, null); } } diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/ViewResolutionResultHandler.java b/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/ViewResolutionResultHandler.java index 31ea08126c..445116d557 100644 --- a/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/ViewResolutionResultHandler.java +++ b/spring-webflux/src/main/java/org/springframework/web/reactive/result/view/ViewResolutionResultHandler.java @@ -55,13 +55,13 @@ import org.springframework.web.server.support.HttpRequestPathHelper; * {@code HandlerResultHandler} that encapsulates the view resolution algorithm * supporting the following return types: *

    - *
  • String-based view name - *
  • Reference to a {@link View} - *
  • {@link Model} - *
  • {@link Map} - *
  • Return types annotated with {@code @ModelAttribute} - *
  • {@link BeanUtils#isSimpleProperty Non-simple} return types are - * treated as a model attribute + *
  • {@link Void} or no value -- default view name
    • + *
  • {@link String} -- view name unless {@code @ModelAttribute}-annotated + *
  • {@link View} -- View to render with + *
  • {@link Model} -- attributes to add to the model + *
  • {@link Map} -- attributes to add to the model + *
  • {@link ModelAttribute @ModelAttribute} -- attribute for the model + *
  • Non-simple value -- attribute for the model *
* *

A String-based view name is resolved through the configured @@ -71,8 +71,9 @@ import org.springframework.web.server.support.HttpRequestPathHelper; * *

By default this resolver is ordered at {@link Ordered#LOWEST_PRECEDENCE} * and generally needs to be late in the order since it interprets any String - * return value as a view name while others may interpret the same otherwise - * based on annotations (e.g. for {@code @ResponseBody}). + * return value as a view name or any non-simple value type as a model attribute + * while other result handlers may interpret the same otherwise based on the + * presence of annotations, e.g. for {@code @ResponseBody}. * * @author Rossen Stoyanchev * @since 5.0 @@ -174,11 +175,16 @@ public class ViewResolutionResultHandler extends HandlerResultHandlerSupport ReactiveAdapter adapter = getAdapter(result); if (adapter != null) { - Assert.isTrue(!adapter.isMultiValue(), "Only single-value async return type supported."); + Assert.isTrue(!adapter.isMultiValue(), "Multi-value " + + "reactive types not supported in view resolution: " + result.getReturnType()); + valueMono = result.getReturnValue() - .map(value -> Mono.from(adapter.toPublisher(value))).orElse(Mono.empty()); + .map(value -> Mono.from(adapter.toPublisher(value))) + .orElse(Mono.empty()); + valueType = adapter.isNoValue() ? - ResolvableType.forClass(Void.class) : result.getReturnType().getGeneric(0); + ResolvableType.forClass(Void.class) : + result.getReturnType().getGeneric(0); } else { valueMono = Mono.justOrEmpty(result.getReturnValue()); @@ -224,7 +230,7 @@ public class ViewResolutionResultHandler extends HandlerResultHandlerSupport viewsMono = resolveViews(getDefaultViewName(exchange), locale); } - addBindingResult(result.getBindingContext(), exchange); + updateBindingContext(result.getBindingContext(), exchange); return viewsMono.then(views -> render(views, model.asMap(), exchange)); }); @@ -259,11 +265,6 @@ public class ViewResolutionResultHandler extends HandlerResultHandlerSupport }); } - /** - * Return the name of a model attribute return value based on the method - * {@code @ModelAttribute} annotation, if present, or derived from the type - * of the return value otherwise. - */ private String getNameForReturnValue(Class returnValueType, MethodParameter returnType) { ModelAttribute annotation = returnType.getMethodAnnotation(ModelAttribute.class); if (annotation != null && StringUtils.hasText(annotation.value())) { @@ -273,9 +274,7 @@ public class ViewResolutionResultHandler extends HandlerResultHandlerSupport return ClassUtils.getShortNameAsProperty(returnValueType); } - - - private void addBindingResult(BindingContext context, ServerWebExchange exchange) { + private void updateBindingContext(BindingContext context, ServerWebExchange exchange) { Map model = context.getModel().asMap(); model.keySet().stream() .filter(name -> isBindingCandidate(name, model.get(name))) diff --git a/spring-webflux/src/test/java/org/springframework/web/reactive/result/view/HttpMessageWriterViewTests.java b/spring-webflux/src/test/java/org/springframework/web/reactive/result/view/HttpMessageWriterViewTests.java index 938af497d0..2a25353e0f 100644 --- a/spring-webflux/src/test/java/org/springframework/web/reactive/result/view/HttpMessageWriterViewTests.java +++ b/spring-webflux/src/test/java/org/springframework/web/reactive/result/view/HttpMessageWriterViewTests.java @@ -20,16 +20,15 @@ import java.nio.charset.StandardCharsets; import java.time.Duration; import java.util.Arrays; import java.util.Collections; -import java.util.HashMap; import java.util.HashSet; import java.util.LinkedHashMap; -import java.util.List; import java.util.Map; import org.junit.Test; import reactor.test.StepVerifier; import org.springframework.core.codec.CharSequenceEncoder; +import org.springframework.core.io.buffer.DataBuffer; import org.springframework.core.io.buffer.support.DataBufferTestUtils; import org.springframework.http.MediaType; import org.springframework.http.codec.json.Jackson2JsonEncoder; @@ -38,12 +37,9 @@ import org.springframework.mock.http.server.reactive.test.MockServerHttpRequest; import org.springframework.mock.http.server.reactive.test.MockServerWebExchange; import org.springframework.ui.ExtendedModelMap; import org.springframework.ui.ModelMap; -import org.springframework.util.MimeType; import static junit.framework.TestCase.assertTrue; import static org.junit.Assert.assertEquals; -import static org.junit.Assert.assertNotNull; -import static org.junit.Assert.assertNull; import static org.junit.Assert.fail; @@ -55,62 +51,65 @@ public class HttpMessageWriterViewTests { private HttpMessageWriterView view = new HttpMessageWriterView(new Jackson2JsonEncoder()); - private ModelMap model = new ExtendedModelMap(); + private final ModelMap model = new ExtendedModelMap(); + + private final MockServerWebExchange exchange = MockServerHttpRequest.get("/").toExchange(); @Test public void supportedMediaTypes() throws Exception { - List mimeTypes = Arrays.asList( - new MimeType("application", "json", StandardCharsets.UTF_8), - new MimeType("application", "*+json", StandardCharsets.UTF_8)); - - assertEquals(mimeTypes, this.view.getSupportedMediaTypes()); + assertEquals(Arrays.asList( + MediaType.parseMediaType("application/json;charset=UTF-8"), + MediaType.parseMediaType("application/*+json;charset=UTF-8")), + this.view.getSupportedMediaTypes()); } @Test - public void extractObject() throws Exception { + public void singleMatch() throws Exception { this.view.setModelKeys(Collections.singleton("foo2")); this.model.addAttribute("foo1", "bar1"); this.model.addAttribute("foo2", "bar2"); this.model.addAttribute("foo3", "bar3"); - assertEquals("bar2", this.view.extractObjectToRender(this.model)); + assertEquals("\"bar2\"", doRender()); } @Test - public void extractObjectNoMatch() throws Exception { + public void noMatch() throws Exception { this.view.setModelKeys(Collections.singleton("foo2")); this.model.addAttribute("foo1", "bar1"); - assertNull(this.view.extractObjectToRender(this.model)); + assertEquals("", doRender()); } @Test - public void extractObjectMultipleMatches() throws Exception { + public void noMatchBecauseNotSupported() throws Exception { + this.view = new HttpMessageWriterView(new Jaxb2XmlEncoder()); + this.view.setModelKeys(new HashSet<>(Collections.singletonList("foo1"))); + this.model.addAttribute("foo1", "bar1"); + + assertEquals("", doRender()); + } + + @Test + public void multipleMatches() throws Exception { this.view.setModelKeys(new HashSet<>(Arrays.asList("foo1", "foo2"))); this.model.addAttribute("foo1", "bar1"); this.model.addAttribute("foo2", "bar2"); this.model.addAttribute("foo3", "bar3"); - Object value = this.view.extractObjectToRender(this.model); - assertNotNull(value); - assertEquals(HashMap.class, value.getClass()); - - Map map = (Map) value; - assertEquals(2, map.size()); - assertEquals("bar1", map.get("foo1")); - assertEquals("bar2", map.get("foo2")); + assertEquals("{\"foo1\":\"bar1\",\"foo2\":\"bar2\"}", doRender()); } @Test - public void extractObjectMultipleMatchesNotSupported() throws Exception { - HttpMessageWriterView view = new HttpMessageWriterView(CharSequenceEncoder.allMimeTypes()); - view.setModelKeys(new HashSet<>(Arrays.asList("foo1", "foo2"))); + public void multipleMatchesNotSupported() throws Exception { + this.view = new HttpMessageWriterView(CharSequenceEncoder.allMimeTypes()); + this.view.setModelKeys(new HashSet<>(Arrays.asList("foo1", "foo2"))); this.model.addAttribute("foo1", "bar1"); this.model.addAttribute("foo2", "bar2"); try { - view.extractObjectToRender(this.model); + doRender(); fail(); } catch (IllegalStateException ex) { @@ -119,22 +118,6 @@ public class HttpMessageWriterViewTests { } } - @Test - public void extractObjectNotSupported() throws Exception { - HttpMessageWriterView view = new HttpMessageWriterView(new Jaxb2XmlEncoder()); - view.setModelKeys(new HashSet<>(Collections.singletonList("foo1"))); - this.model.addAttribute("foo1", "bar1"); - - try { - view.extractObjectToRender(this.model); - fail(); - } - catch (IllegalStateException ex) { - String message = ex.getMessage(); - assertTrue(message, message.contains("[foo1] is not supported")); - } - } - @Test public void render() throws Exception { Map pojoData = new LinkedHashMap<>(); @@ -143,18 +126,24 @@ public class HttpMessageWriterViewTests { this.model.addAttribute("pojoData", pojoData); this.view.setModelKeys(Collections.singleton("pojoData")); - MockServerWebExchange exchange = MockServerHttpRequest.get("/path").toExchange(); + this.view.render(this.model, MediaType.APPLICATION_JSON, exchange).block(Duration.ZERO); - this.view.render(this.model, MediaType.APPLICATION_JSON, exchange).block(Duration.ofSeconds(5)); - - StepVerifier.create(exchange.getResponse().getBody()) - .consumeNextWith( buf -> assertEquals("{\"foo\":\"f\",\"bar\":\"b\"}", - DataBufferTestUtils.dumpString(buf, StandardCharsets.UTF_8)) - ) + StepVerifier.create(this.exchange.getResponse().getBody()) + .consumeNextWith(buf -> assertEquals("{\"foo\":\"f\",\"bar\":\"b\"}", dumpString(buf))) .expectComplete() .verify(); } + private String dumpString(DataBuffer buf) { + return DataBufferTestUtils.dumpString(buf, StandardCharsets.UTF_8); + } + + private String doRender() { + this.view.render(this.model, MediaType.APPLICATION_JSON, this.exchange).block(Duration.ZERO); + return this.exchange.getResponse().getBodyAsString().block(Duration.ZERO); + } + + @SuppressWarnings("unused") private String handle() {