Working with Archive Files - Beginning Java 8 Language Features - page 380

/* Add main attributes
1. Manifest Version
2. Main-Class
3. Sealed
*/
Attributes mainAttribs = manifest.getMainAttributes();
mainAttribs.put(Attributes.Name.MANIFEST_VERSION, "1.0");
mainAttribs.put(Attributes.Name.MAIN_CLASS, "com.jdojo.intro.Welcome");
mainAttribs.put(Attributes.Name.SEALED, "true");

Adding an individual entry to the manifest file is a little more complex than adding the main entry. Suppose you
want to add the following individual entry to a manifest file:

Name: "com/jdojo/archives/"
Sealed: false

You need to perform the following steps.

1. Get the Map object that stores the individual entries for a manifest.

2. Create an Attributes object.

3. Add the name-value pair to the Attributes object. You can add as many name-value pairs

as you want.

4. Add the Attributes object to the attribute Map using the name of the individual section as

the key.

The following snippet of code shows you how to add an individual entry to a Manifest object:

// Get the Attribute map for the Manifest
Map<String,Attributes> attribsMap = manifest.getEntries();

// Create an Attributes object
Attributes attribs = new Attributes();

// Create an Attributes.Name object for the "Sealed" attribute
Attributes.Name name = new Attributes.Name("Sealed");

// Add the "name: value" pair (Sealed: false) to the attributes objects
attribs.put(name, "false");

// Add the Sealed: false attibute to the attributes map
attribsMap.put("com/jdojo/archives/", attribs);

If you want to add a manifest file to a JAR file, you can specify it in one of the constructors of the JarOutputStream
class. For example, the following snippet of code creates a jar output stream to create a test.jar file with a Manifest
object:

// Create a Manifest object
Manifest manifest = new Manifest();