This is an example of how to write a JAR file Manifest to a file. A JAR file is essentially a zip file that contains an optional META-INF directory. In this directory there is a Manifest, that is used to specify meta-information about the jar file and its entries. Writing a JAR file’s Manifest to a file implies that you should:
- Create a new JarFile to read from the specified jar file.
- Get the Manifest for that file, using the
getManifest()API method of the JarFile. - Write the manifest to a file, using a FileOutputStream and the
write(OutputStream out)API method of the Manifest,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
public class WriteJARFileManifestToFile {
public static void main(String[] args) throws Exception {
// create a new JAR file to read from the specified file
JarFile jarfile = new JarFile("jsp-api.jar");
// get the manifest for that file
Manifest manifest = jarfile.getManifest();
// write the manifest to a file
OutputStream fos = new FileOutputStream("Manifest.MF");
manifest.write(fos);
fos.close();
}
}
Output:
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.8.0
Created-By: 1.6.0_20-b02 (Sun Microsystems Inc.)
X-Compile-Source-JDK: 1.6
X-Compile-Target-JDK: 1.6
Name: javax/servlet/jsp/
Implementation-Vendor: Apache Software Foundation
Specification-Title: Java API for JavaServer Pages
Implementation-Title: javax.servlet.jsp
Implementation-Version: 2.2.FR
Specification-Version: 2.2
Specification-Vendor: Sun Microsystems, Inc.
This was an example of how to write a JAR file Manifest to a file in Java.
