With this example we are going to demonstrate how to create a Manifest for a JAR File. In short, to create a Manifest for a JAR File you should:
- Create a FileInputStream by opening a connection to an actual file.
- Create a new Manifest from the specified input stream.
- Invoke the
getMainAttributes()API method of the Manifest to get the Attributes of the Manifest. - Get the Collection view of the attribute name-value mappings contained in the Attributes, with the
entrySet()API method of the Attributes. - Use an Iterator to get the entries of the Attributes.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.jar.Attributes;
import java.util.jar.Manifest;
public class CreateManifestForJARFile {
public static void main(String[] args) throws Exception {
// Create a manifest from a file
InputStream fis = new FileInputStream("Manifest.MF");
Manifest manifest = new Manifest(fis);
Attributes attrs = manifest.getMainAttributes();
Set<Map.Entry<Object,Object>> set = attrs.entrySet();
Iterator<Map.Entry<Object,Object>> iter = set.iterator();
while (iter.hasNext()) {
Map.Entry<Object, Object> entry = iter.next();
System.out.println(entry);
}
}
}
Manifest.MF:
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/
Specification-Title: Java API for JavaServer Pages
Specification-Version: 2.2
Specification-Vendor: Sun Microsystems, Inc.
Implementation-Title: javax.servlet.jsp
Implementation-Version: 2.2.FR
Implementation-Vendor: Apache Software Foundation
Output:
Ant-Version=Apache Ant 1.8.0
Manifest-Version=1.0
Created-By=1.6.0_20-b02 (Sun Microsystems Inc.)
X-Compile-Source-JDK=1.6
X-Compile-Target-JDK=1.6
This was an example of how to create a Manifest for a JAR File in Java.
