Upgrade to Jetty 12.0.12

Closes gh-41770

Author: snicoll

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -687,7 +687,7 @@ bom {
 			]
 		}
 	}
-	library("Jetty", "12.0.11") {
+	library("Jetty", "12.0.12") {
 		group("org.eclipse.jetty.ee10") {
 			imports = [
 				"jetty-ee10-bom"

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/jetty/JettyEmbeddedWebAppContext.java

@@ -42,6 +42,11 @@ void deferredInitialize() throws Exception {
 		getContext().call(handler::deferredInitialize, null);
 	}
 
+	@Override
+	public String getCanonicalNameForTmpDir() {
+		return super.getCanonicalNameForTmpDir();
+	}
+
 	private static final class JettyEmbeddedServletHandler extends ServletHandler {
 
 		@Override

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/jetty/JettyServletWebServerFactory.java

@@ -308,9 +308,17 @@ private void addLocaleMappings(WebAppContext context) {
 
 	private File getTempDirectory(WebAppContext context) {
 		String temp = System.getProperty("java.io.tmpdir");
-		return (temp != null)
-				? new File(temp, WebInfConfiguration.getCanonicalNameForWebAppTmpDir(context) + UUID.randomUUID())
-				: null;
+		return (temp != null) ? new File(temp, getTempDirectoryPrefix(context) + UUID.randomUUID()) : null;
+	}
+
+	@SuppressWarnings("removal")
+	private String getTempDirectoryPrefix(WebAppContext context) {
+		try {
+			return ((JettyEmbeddedWebAppContext) context).getCanonicalNameForTmpDir();
+		}
+		catch (Throwable ex) {
+			return WebInfConfiguration.getCanonicalNameForWebAppTmpDir(context);
+		}
 	}
 
 	private void configureDocumentRoot(WebAppContext handler) {