Update ScriptTemplateView to manage content type

This commit introduces the following changes:
 - Content type can now be properly configured
 - Default content type is "text/html"
 - Content type and charset are now properly set in the response

Issue: SPR-13379

spring-webmvc/src/main/java/org/springframework/web/servlet/config/ScriptTemplateConfigurerBeanDefinitionParser.java

@@ -67,6 +67,9 @@ public class ScriptTemplateConfigurerBeanDefinitionParser extends AbstractSimple
 		if (element.hasAttribute("render-function")) {
 			builder.addPropertyValue("renderFunction", element.getAttribute("render-function"));
 		}
+		if (element.hasAttribute("content-type")) {
+			builder.addPropertyValue("contentType", element.getAttribute("content-type"));
+		}
 		if (element.hasAttribute("charset")) {
 			builder.addPropertyValue("charset", Charset.forName(element.getAttribute("charset")));
 		}
@@ -81,7 +84,8 @@ public class ScriptTemplateConfigurerBeanDefinitionParser extends AbstractSimple
 	@Override
 	protected boolean isEligibleAttribute(String name) {
 		return (name.equals("engine-name") || name.equals("scripts") || name.equals("render-object") ||
-				name.equals("render-function") || name.equals("charset") || name.equals("resource-loader-path"));
+				name.equals("render-function") || name.equals("content-type") ||
+				name.equals("charset") || name.equals("resource-loader-path"));
 	}
 
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/view/script/ScriptTemplateConfig.java

@@ -60,6 +60,12 @@ public interface ScriptTemplateConfig {
 	 */
 	String getRenderFunction();
 
+	/**
+	 * Return the content type to use for the response.
+	 * @since 4.2.1
+	 */
+	String getContentType();
+
 	/**
 	 * Return the charset used to read script and template files.
 	 */

spring-webmvc/src/main/java/org/springframework/web/servlet/view/script/ScriptTemplateConfigurer.java

@@ -59,6 +59,8 @@ public class ScriptTemplateConfigurer implements ScriptTemplateConfig {
 
 	private String renderFunction;
 
+	private String contentType;
+
 	private Charset charset;
 
 	private String resourceLoaderPath;
@@ -170,6 +172,24 @@ public class ScriptTemplateConfigurer implements ScriptTemplateConfig {
 		return this.renderFunction;
 	}
 
+	/**
+	 * Set the content type to use for the response.
+	 * ({@code text/html} by default).
+	 * @since 4.2.1
+	 */
+	public void setContentType(String contentType) {
+		this.contentType = contentType;
+	}
+
+	/**
+	 * Return the content type to use for the response.
+	 * @since 4.2.1
+	 */
+	@Override
+	public String getContentType() {
+		return this.contentType;
+	}
+
 	/**
 	 * Set the charset used to read script and template files.
 	 * ({@code UTF-8} by default).

spring-webmvc/src/main/java/org/springframework/web/servlet/view/script/ScriptTemplateView.java

@@ -63,6 +63,8 @@ import org.springframework.web.servlet.view.AbstractUrlBasedView;
  */
 public class ScriptTemplateView extends AbstractUrlBasedView {
 
+	public static final String DEFAULT_CONTENT_TYPE = "text/html";
+
 	private static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
 
 	private static final String DEFAULT_RESOURCE_LOADER_PATH = "classpath:";
@@ -89,6 +91,24 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 	private String resourceLoaderPath;
 
 
+	/**
+	 * Constructor for use as a bean.
+	 * @see #setUrl
+	 */
+	public ScriptTemplateView() {
+		setContentType(null);
+	}
+
+	/**
+	 * Create a new ScriptTemplateView with the given URL.
+	 * @since 4.2.1
+	 */
+	public ScriptTemplateView(String url) {
+		super(url);
+		setContentType(null);
+	}
+
+
 	/**
 	 * See {@link ScriptTemplateConfigurer#setEngine(ScriptEngine)} documentation.
 	 */
@@ -132,6 +152,15 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 		this.renderFunction = functionName;
 	}
 
+	/**
+	 * See {@link ScriptTemplateConfigurer#setContentType(String)}} documentation.
+	 * @since 4.2.1
+	 */
+	@Override
+	public void setContentType(String contentType) {
+		super.setContentType(contentType);
+	}
+
 	/**
 	 * See {@link ScriptTemplateConfigurer#setCharset(Charset)} documentation.
 	 */
@@ -167,6 +196,9 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 		if (this.renderFunction == null && viewConfig.getRenderFunction() != null) {
 			this.renderFunction = viewConfig.getRenderFunction();
 		}
+		if (this.getContentType() == null) {
+			setContentType(viewConfig.getContentType() != null ? viewConfig.getContentType() : DEFAULT_CONTENT_TYPE);
+		}
 		if (this.charset == null) {
 			this.charset = (viewConfig.getCharset() != null ? viewConfig.getCharset() : DEFAULT_CHARSET);
 		}
@@ -276,10 +308,17 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 		}
 	}
 
+	@Override
+	protected void prepareResponse(HttpServletRequest request, HttpServletResponse response) {
+		super.prepareResponse(request, response);
+
+		setResponseContentType(request, response);
+		response.setCharacterEncoding(this.charset.name());
+	}
 
 	@Override
-	protected void renderMergedOutputModel(
+	protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request,
-			Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
+			HttpServletResponse response) throws Exception {
 
 		try {
 			ScriptEngine engine = getEngine();

spring-webmvc/src/main/resources/org/springframework/web/servlet/config/spring-mvc-4.2.xsd

@@ -1252,6 +1252,13 @@
 					]]></xsd:documentation>
 				</xsd:annotation>
 			</xsd:attribute>
+			<xsd:attribute name="content-type" type="xsd:string">
+				<xsd:annotation>
+					<xsd:documentation><![CDATA[
+	Set the content type to use for the response (text/html by default).
+					]]></xsd:documentation>
+				</xsd:annotation>
+			</xsd:attribute>
 			<xsd:attribute name="charset" type="xsd:string">
 				<xsd:annotation>
 					<xsd:documentation><![CDATA[

spring-webmvc/src/test/java/org/springframework/web/servlet/config/MvcNamespaceTests.java

@@ -799,6 +799,7 @@ public class MvcNamespaceTests {
 		ScriptTemplateConfigurer scriptTemplateConfigurer = appContext.getBean(ScriptTemplateConfigurer.class);
 		assertNotNull(scriptTemplateConfigurer);
 		assertEquals("render", scriptTemplateConfigurer.getRenderFunction());
+		assertEquals(MediaType.TEXT_PLAIN_VALUE, scriptTemplateConfigurer.getContentType());
 		assertEquals(StandardCharsets.ISO_8859_1, scriptTemplateConfigurer.getCharset());
 		assertEquals("classpath:", scriptTemplateConfigurer.getResourceLoaderPath());
 		assertFalse(scriptTemplateConfigurer.isSharedEngine());

spring-webmvc/src/test/java/org/springframework/web/servlet/view/script/ScriptTemplateViewTests.java

@@ -20,7 +20,9 @@ import java.net.URLClassLoader;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
@@ -34,6 +36,13 @@ import org.junit.Test;
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.context.ApplicationContextException;
 import org.springframework.context.support.StaticApplicationContext;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.mock.web.test.MockHttpServletRequest;
+import org.springframework.mock.web.test.MockHttpServletResponse;
+import org.springframework.mock.web.test.MockServletContext;
+import org.springframework.web.context.support.StaticWebApplicationContext;
+import org.springframework.web.servlet.DispatcherServlet;
 
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
@@ -51,7 +60,7 @@ public class ScriptTemplateViewTests {
 
 	private ScriptTemplateConfigurer configurer;
 
-	private StaticApplicationContext applicationContext;
+	private StaticWebApplicationContext wac;
 
 	private static final String RESOURCE_LOADER_PATH = "classpath:org/springframework/web/servlet/view/script/";
 
@@ -59,10 +68,10 @@ public class ScriptTemplateViewTests {
 	@Before
 	public void setup() {
 		this.configurer = new ScriptTemplateConfigurer();
-		this.applicationContext = new StaticApplicationContext();
+		this.wac = new StaticWebApplicationContext();
-		this.applicationContext.getBeanFactory().registerSingleton("scriptTemplateConfigurer", this.configurer);
+		this.wac.getBeanFactory().registerSingleton("scriptTemplateConfigurer", this.configurer);
 		this.view = new ScriptTemplateView();
-		this.view.setUrl("sampleView");
+		this.view.setUrl(RESOURCE_LOADER_PATH + "empty.txt");
 	}
 
 	@Test
@@ -83,13 +92,18 @@ public class ScriptTemplateViewTests {
 		this.configurer.setEngine(engine);
 		this.configurer.setRenderObject("Template");
 		this.configurer.setRenderFunction("render");
+		this.configurer.setContentType(MediaType.TEXT_PLAIN_VALUE);
 		this.configurer.setCharset(StandardCharsets.ISO_8859_1);
+		this.configurer.setSharedEngine(true);
+
 		DirectFieldAccessor accessor = new DirectFieldAccessor(this.view);
-		this.view.setApplicationContext(this.applicationContext);
+		this.view.setApplicationContext(this.wac);
 		assertEquals(engine, accessor.getPropertyValue("engine"));
 		assertEquals("Template", accessor.getPropertyValue("renderObject"));
 		assertEquals("render", accessor.getPropertyValue("renderFunction"));
+		assertEquals(MediaType.TEXT_PLAIN_VALUE, accessor.getPropertyValue("contentType"));
 		assertEquals(StandardCharsets.ISO_8859_1, accessor.getPropertyValue("charset"));
+		assertEquals(true, accessor.getPropertyValue("sharedEngine"));
 	}
 
 	@Test
@@ -97,16 +111,15 @@ public class ScriptTemplateViewTests {
 		this.configurer.setEngineName("nashorn");
 		this.configurer.setRenderObject("Template");
 		this.configurer.setRenderFunction("render");
-		this.configurer.setCharset(StandardCharsets.ISO_8859_1);
+
-		this.configurer.setSharedEngine(true);
 		DirectFieldAccessor accessor = new DirectFieldAccessor(this.view);
-		this.view.setApplicationContext(this.applicationContext);
+		this.view.setApplicationContext(this.wac);
 		assertEquals("nashorn", accessor.getPropertyValue("engineName"));
 		assertNotNull(accessor.getPropertyValue("engine"));
 		assertEquals("Template", accessor.getPropertyValue("renderObject"));
 		assertEquals("render", accessor.getPropertyValue("renderFunction"));
-		assertEquals(StandardCharsets.ISO_8859_1, accessor.getPropertyValue("charset"));
+		assertEquals(MediaType.TEXT_HTML_VALUE, accessor.getPropertyValue("contentType"));
-		assertEquals(true, accessor.getPropertyValue("sharedEngine"));
+		assertEquals(StandardCharsets.UTF_8, accessor.getPropertyValue("charset"));
 	}
 
 	@Test
@@ -115,7 +128,7 @@ public class ScriptTemplateViewTests {
 		given(engine.get("key")).willReturn("value");
 		this.view.setEngine(engine);
 		this.view.setRenderFunction("render");
-		this.view.setApplicationContext(this.applicationContext);
+		this.view.setApplicationContext(this.wac);
 		engine = this.view.getEngine();
 		assertNotNull(engine);
 		assertEquals("value", engine.get("key"));
@@ -131,7 +144,7 @@ public class ScriptTemplateViewTests {
 		this.view.setEngineName("nashorn");
 		this.view.setRenderFunction("render");
 		this.view.setSharedEngine(false);
-		this.view.setApplicationContext(this.applicationContext);
+		this.view.setApplicationContext(this.wac);
 		ExecutorService executor = Executors.newFixedThreadPool(4);
 		List<Future<Boolean>> results = new ArrayList<>();
 		for(int i = 0; i < iterations; i++) {
@@ -160,7 +173,7 @@ public class ScriptTemplateViewTests {
 	public void noRenderFunctionDefined() {
 		this.view.setEngine(mock(InvocableScriptEngine.class));
 		try {
-			this.view.setApplicationContext(this.applicationContext);
+			this.view.setApplicationContext(this.wac);
 			fail("Should have thrown IllegalArgumentException");
 		}
 		catch (IllegalArgumentException ex) {
@@ -174,7 +187,7 @@ public class ScriptTemplateViewTests {
 		this.view.setEngineName("test");
 		this.view.setRenderFunction("render");
 		try {
-			this.view.setApplicationContext(this.applicationContext);
+			this.view.setApplicationContext(this.wac);
 			fail("Should have thrown IllegalArgumentException");
 		}
 		catch (IllegalArgumentException ex) {
@@ -188,7 +201,7 @@ public class ScriptTemplateViewTests {
 		this.view.setRenderFunction("render");
 		this.view.setSharedEngine(false);
 		try {
-			this.view.setApplicationContext(this.applicationContext);
+			this.view.setApplicationContext(this.wac);
 			fail("Should have thrown IllegalArgumentException");
 		}
 		catch (IllegalArgumentException ex) {
@@ -203,7 +216,7 @@ public class ScriptTemplateViewTests {
 		this.view.setEngine(mock(InvocableScriptEngine.class));
 		this.view.setRenderFunction("render");
 		this.view.setResourceLoaderPath(RESOURCE_LOADER_PATH);
-		this.view.setApplicationContext(this.applicationContext);
+		this.view.setApplicationContext(this.wac);
 		ClassLoader classLoader = this.view.createClassLoader();
 		assertNotNull(classLoader);
 		URLClassLoader urlClassLoader = (URLClassLoader) classLoader;
@@ -219,6 +232,38 @@ public class ScriptTemplateViewTests {
 		assertThat(Arrays.asList(urlClassLoader.getURLs()).get(1).toString(), Matchers.endsWith("org/springframework/web/servlet/view/"));
 	}
 
+	@Test // SPR-13379
+	public void contentType() throws Exception {
+		MockServletContext servletContext = new MockServletContext();
+		this.wac.setServletContext(servletContext);
+		this.wac.refresh();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setAttribute(DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE, this.wac);
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		Map<String, Object> model = new HashMap<String, Object>();
+		this.view.setEngine(mock(InvocableScriptEngine.class));
+		this.view.setRenderFunction("render");
+		this.view.setResourceLoaderPath(RESOURCE_LOADER_PATH);
+		this.view.setApplicationContext(this.wac);
+
+		this.view.render(model, request, response);
+		assertEquals(MediaType.TEXT_HTML_VALUE + ";charset=" +
+				StandardCharsets.UTF_8, response.getHeader(HttpHeaders.CONTENT_TYPE));
+
+		response = new MockHttpServletResponse();
+		this.view.setContentType(MediaType.TEXT_PLAIN_VALUE);
+		this.view.render(model, request, response);
+		assertEquals(MediaType.TEXT_PLAIN_VALUE + ";charset=" +
+				StandardCharsets.UTF_8, response.getHeader(HttpHeaders.CONTENT_TYPE));
+
+		response = new MockHttpServletResponse();
+		this.view.setCharset(StandardCharsets.ISO_8859_1);
+		this.view.render(model, request, response);
+		assertEquals(MediaType.TEXT_PLAIN_VALUE + ";charset=" +
+				StandardCharsets.ISO_8859_1, response.getHeader(HttpHeaders.CONTENT_TYPE));
+
+	}
+
 
 	private interface InvocableScriptEngine extends ScriptEngine, Invocable {
 	}

spring-webmvc/src/test/resources/org/springframework/web/servlet/config/mvc-config-view-resolution.xml

@@ -34,7 +34,8 @@
 
 	<mvc:groovy-configurer resource-loader-path="/test" cache-templates="false" auto-indent="true" />
 
-	<mvc:script-template-configurer engine-name="nashorn" render-function="render" charset="ISO-8859-1"
+	<mvc:script-template-configurer engine-name="nashorn" render-function="render"
+									content-type="text/plain" charset="ISO-8859-1"
 									resource-loader-path="classpath:" shared-engine="false">
 		<mvc:script location="org/springframework/web/servlet/view/script/nashorn/render.js" />
 	</mvc:script-template-configurer>