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(
-			Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
+	protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request,
+			HttpServletResponse response) throws Exception {
 
 		try {
 			ScriptEngine engine = getEngine();