Fix handling of static resource jar paths containing a +

Closes gh-12942

spring-boot-integration-tests/spring-boot-integration-tests-embedded-servlet-container/src/test/java/org/springframework/boot/context/embedded/IdeApplicationLauncher.java

@@ -40,7 +40,7 @@ import org.springframework.util.StringUtils;
  */
 class IdeApplicationLauncher extends AbstractApplicationLauncher {
 
-	private final File exploded = new File("target/ide application");
+	private final File exploded = new File("target/the+ide application");
 
 	IdeApplicationLauncher(ApplicationBuilder applicationBuilder) {
 		super(applicationBuilder);

spring-boot/src/main/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactory.java

@@ -109,7 +109,7 @@ public abstract class AbstractEmbeddedServletContainerFactory
 	private boolean isStaticResourceJar(URL url) {
 		try {
 			if ("file".equals(url.getProtocol())) {
-				File file = new File(getDecodedFile(url));
+				File file = new File(url.toURI());
 				return (file.isDirectory()
 						&& new File(file, "META-INF/resources").isDirectory())
 						|| isResourcesJar(file);
@@ -122,12 +122,20 @@ public abstract class AbstractEmbeddedServletContainerFactory
 				}
 			}
 		}
-		catch (IOException ex) {
+		catch (Exception ex) {
 			throw new IllegalStateException(ex);
 		}
 		return false;
 	}
 
+	/**
+	 * Converts the given {@code url} into a decoded file path.
+	 *
+	 * @param url the url to convert
+	 * @return the file path
+	 * @deprecated Since 1.5.13 in favor of {@link File#File(java.net.URI)}
+	 */
+	@Deprecated
 	protected final String getDecodedFile(URL url) {
 		try {
 			return URLDecoder.decode(url.getFile(), "UTF-8");

spring-boot/src/main/java/org/springframework/boot/context/embedded/jetty/JettyEmbeddedServletContainerFactory.java

@@ -431,9 +431,9 @@ public class JettyEmbeddedServletContainerFactory
 		}
 	}
 
-	private Resource createResource(URL url) throws IOException {
+	private Resource createResource(URL url) throws Exception {
 		if ("file".equals(url.getProtocol())) {
-			File file = new File(getDecodedFile(url));
+			File file = new File(url.toURI());
 			if (file.isFile()) {
 				return Resource.newResource("jar:" + url + "!/META-INF/resources");
 			}

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/TomcatResources.java

@@ -16,11 +16,11 @@
 
 package org.springframework.boot.context.embedded.tomcat;
 
-import java.io.UnsupportedEncodingException;
+import java.io.File;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
+import java.net.URISyntaxException;
 import java.net.URL;
-import java.net.URLDecoder;
 import java.util.List;
 
 import javax.naming.directory.DirContext;
@@ -49,31 +49,27 @@ abstract class TomcatResources {
 
 	void addResourceJars(List<URL> resourceJarUrls) {
 		for (URL url : resourceJarUrls) {
-			String file = getDecodedFile(url);
-			if (file.endsWith(".jar") || file.endsWith(".jar!/")) {
-				String jar = url.toString();
-				if (!jar.startsWith("jar:")) {
-					// A jar file in the file system. Convert to Jar URL.
-					jar = "jar:" + jar + "!/";
+			try {
+				String path = url.getPath();
+				if (path.endsWith(".jar") || path.endsWith(".jar!/")) {
+					String jar = url.toString();
+					if (!jar.startsWith("jar:")) {
+						// A jar file in the file system. Convert to Jar URL.
+						jar = "jar:" + jar + "!/";
+					}
+					addJar(jar);
+				}
+				else {
+					addDir(new File(url.toURI()).getAbsolutePath(), url);
 				}
-				addJar(jar);
 			}
-			else {
-				addDir(file, url);
+			catch (URISyntaxException ex) {
+				throw new IllegalStateException(
+						"Failed to create File from URL '" + url + "'");
 			}
 		}
 	}
 
-	private String getDecodedFile(URL url) {
-		try {
-			return URLDecoder.decode(url.getFile(), "UTF-8");
-		}
-		catch (UnsupportedEncodingException ex) {
-			throw new IllegalStateException(
-					"Failed to decode '" + url.getFile() + "' using UTF-8");
-		}
-	}
-
 	protected final Context getContext() {
 		return this.context;
 	}

spring-boot/src/main/java/org/springframework/boot/context/embedded/undertow/UndertowEmbeddedServletContainerFactory.java

@@ -494,18 +494,18 @@ public class UndertowEmbeddedServletContainerFactory
 		resourceManagers.add(rootResourceManager);
 		for (URL url : metaInfResourceUrls) {
 			if ("file".equals(url.getProtocol())) {
-				File file = new File(getDecodedFile(url));
-				if (file.isFile()) {
-					try {
+				try {
+					File file = new File(url.toURI());
+					if (file.isFile()) {
 						resourceJarUrls.add(new URL("jar:" + url + "!/"));
 					}
-					catch (MalformedURLException ex) {
-						throw new RuntimeException(ex);
+					else {
+						resourceManagers.add(new FileResourceManager(
+								new File(file, "META-INF/resources"), 0));
 					}
 				}
-				else {
-					resourceManagers.add(new FileResourceManager(
-							new File(file, "META-INF/resources"), 0));
+				catch (Exception ex) {
+					throw new RuntimeException(ex);
 				}
 			}
 			else {