Fix URL methods in JarURLConnection

Update JarURLConnection to return correct values from `getURL()`,
`getJarFileURL()` and `getEntryName()`.

Fixes gh-973

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/JarURLConnection.java

@@ -51,6 +51,7 @@ class JarURLConnection extends java.net.JarURLConnection {
 
 	protected JarURLConnection(URL url, JarFile jarFile) throws MalformedURLException {
 		super(new URL(buildRootUrl(jarFile)));
+		this.url = url;
 		this.jarFile = jarFile;
 
 		String spec = url.getFile();
@@ -59,27 +60,19 @@ class JarURLConnection extends java.net.JarURLConnection {
 			throw new MalformedURLException("no " + SEPARATOR + " found in url spec:"
 					+ spec);
 		}
-		/*
+		if (separator + 2 != spec.length()) {
-		 * The superclass constructor creates a jarFileUrl which is equal to the root URL
-		 * of the containing archive (therefore not unique if we are connecting to
-		 * multiple nested jars in the same archive). Therefore we need to make something
-		 * sensible for #getJarFileURL().
-		 */
-		if (separator + SEPARATOR.length() != spec.length()) {
 			this.jarEntryName = decode(spec.substring(separator + 2));
-			this.jarFileUrl = new URL("jar:" + spec.substring(0, separator) + SEPARATOR
+		}
-					+ this.jarEntryName);
+
+		String container = spec.substring(0, separator);
+		if (container.indexOf(SEPARATOR) == -1) {
+			this.jarFileUrl = new URL(container);
 		}
 		else {
-			this.jarFileUrl = new URL("jar:" + spec.substring(0, separator));
+			this.jarFileUrl = new URL("jar:" + container);
 		}
 	}
 
-	@Override
-	public URL getJarFileURL() {
-		return this.jarFileUrl;
-	}
-
 	@Override
 	public void connect() throws IOException {
 		if (this.jarEntryName != null) {
@@ -108,12 +101,22 @@ class JarURLConnection extends java.net.JarURLConnection {
 		return this.jarFile;
 	}
 
+	@Override
+	public URL getJarFileURL() {
+		return this.jarFileUrl;
+	}
+
 	@Override
 	public JarEntry getJarEntry() throws IOException {
 		connect();
 		return (this.jarEntryData == null ? null : this.jarEntryData.asJarEntry());
 	}
 
+	@Override
+	public String getEntryName() {
+		return this.jarEntryName;
+	}
+
 	@Override
 	public InputStream getInputStream() throws IOException {
 		connect();

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/JarFileTests.java

@@ -183,7 +183,7 @@ public class JarFileTests {
 		assertThat(jarURLConnection.getContentLength(), greaterThan(1));
 		assertThat(jarURLConnection.getContent(), sameInstance((Object) this.jarFile));
 		assertThat(jarURLConnection.getContentType(), equalTo("x-java/jar"));
-		assertThat(jarURLConnection.getJarFileURL().toString(), equalTo("jar:file:"
+		assertThat(jarURLConnection.getJarFileURL().toString(), equalTo("file:"
 				+ this.rootJarFile));
 	}
 
@@ -296,6 +296,27 @@ public class JarFileTests {
 		InputStream inputStream = url.openStream();
 		assertThat(inputStream, notNullValue());
 		assertThat(inputStream.read(), equalTo(3));
+		JarURLConnection connection = (JarURLConnection) url.openConnection();
+		assertThat(connection.getURL().toString(), equalTo(spec));
+		assertThat(connection.getJarFileURL().toString(), equalTo("jar:file:"
+				+ this.rootJarFile.getPath() + "!/nested.jar"));
+		assertThat(connection.getEntryName(), equalTo("3.dat"));
+	}
+
+	@Test
+	public void createNonNestedUrlFromString() throws Exception {
+		JarFile.registerUrlProtocolHandler();
+		String spec = "jar:file:" + this.rootJarFile.getPath() + "!/2.dat";
+		URL url = new URL(spec);
+		assertThat(url.toString(), equalTo(spec));
+		InputStream inputStream = url.openStream();
+		assertThat(inputStream, notNullValue());
+		assertThat(inputStream.read(), equalTo(2));
+		JarURLConnection connection = (JarURLConnection) url.openConnection();
+		assertThat(connection.getURL().toString(), equalTo(spec));
+		assertThat(connection.getJarFileURL().toString(), equalTo("file:"
+				+ this.rootJarFile.getPath()));
+		assertThat(connection.getEntryName(), equalTo("2.dat"));
 	}
 
 	@Test