Allow entries to be streamed from JarURLConnections' jar file

Fixes gh-23821

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

@@ -24,6 +24,7 @@ import java.security.Permission;
 import java.util.Enumeration;
 import java.util.jar.JarEntry;
 import java.util.jar.Manifest;
+import java.util.stream.Stream;
 import java.util.zip.ZipEntry;
 
 /**
@@ -67,6 +68,11 @@ class JarFileWrapper extends AbstractJarFile {
 		return this.parent.entries();
 	}
 
+	@Override
+	public Stream<JarEntry> stream() {
+		return this.parent.stream();
+	}
+
 	@Override
 	public JarEntry getJarEntry(String name) {
 		return this.parent.getJarEntry(name);

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

@@ -28,6 +28,7 @@ import java.util.Enumeration;
 import java.util.Set;
 import java.util.jar.JarOutputStream;
 import java.util.jar.Manifest;
+import java.util.stream.Stream;
 import java.util.zip.ZipEntry;
 
 import org.junit.jupiter.api.AfterEach;
@@ -150,6 +151,12 @@ class JarFileWrapperTests {
 				.isThrownBy(() -> JarFileWrapper.class.getDeclaredMethod("close"));
 	}
 
+	@Test
+	void streamDelegatestoParent() {
+		this.wrapper.stream();
+		this.parent.verify(Call.STREAM);
+	}
+
 	/**
 	 * {@link JarFile} that we can spy (even on Java 11+)
 	 */
@@ -179,6 +186,12 @@ class JarFileWrapperTests {
 			return super.entries();
 		}
 
+		@Override
+		public Stream<java.util.jar.JarEntry> stream() {
+			mark(Call.STREAM);
+			return super.stream();
+		}
+
 		@Override
 		public JarEntry getJarEntry(String name) {
 			mark(Call.GET_JAR_ENTRY);
@@ -257,7 +270,9 @@ class JarFileWrapperTests {
 
 			GET_COMMENT,
 
-			SIZE
+			SIZE,
+
+			STREAM
 
 		}
 

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

@@ -21,6 +21,9 @@ import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.InputStream;
 import java.net.URL;
+import java.util.List;
+import java.util.jar.JarEntry;
+import java.util.stream.Collectors;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -201,6 +204,14 @@ class JarURLConnectionTests {
 		assertThat(connection.getLastModified()).isEqualTo(connection.getJarEntry().getTime());
 	}
 
+	@Test
+	void entriesCanBeStreamedFromJarFileOfConnection() throws Exception {
+		URL url = new URL("jar:" + this.rootJarFile.toURI().toURL() + "!/");
+		JarURLConnection connection = JarURLConnection.get(url, this.jarFile);
+		List<String> entryNames = connection.getJarFile().stream().map(JarEntry::getName).collect(Collectors.toList());
+		assertThat(entryNames).hasSize(12);
+	}
+
 	@Test
 	void jarEntryBasicName() {
 		assertThat(new JarEntryName(new StringSequence("a/b/C.class")).toString()).isEqualTo("a/b/C.class");