1 files changed, 36 insertions, 0 deletions
diff --git a/bundle-plugin/src/main/java/com/yahoo/container/plugin/util/JarFiles.java b/bundle-plugin/src/main/java/com/yahoo/container/plugin/util/JarFiles.java
new file mode 100644
index 00000000000..398b2f5a72a
--- /dev/null
+++ b/bundle-plugin/src/main/java/com/yahoo/container/plugin/util/JarFiles.java
@@ -0,0 +1,36 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.plugin.util;
+
+import java.io.File;
+import java.io.InputStream;
+import java.util.Optional;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+
+/**
+ * @author Tony Vaagenes
+ * @author ollivir
+ */
+public class JarFiles {
+    public static <T> T withJarFile(File file, ThrowingFunction<JarFile, T> action) {
+        try (JarFile jar = new JarFile(file)) {
+            return action.apply(jar);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static <T> T withInputStream(ZipFile zipFile, ZipEntry zipEntry, ThrowingFunction<InputStream, T> action) {
+        try (InputStream is = zipFile.getInputStream(zipEntry)) {
+            return action.apply(is);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static Optional<Manifest> getManifest(File jarFile) {
+        return withJarFile(jarFile, jar -> Optional.ofNullable(jar.getManifest()));
+    }
+}