An object of the Manifest class represents a manifest file.
You create a Manifest object in your code as follows:
Manifest manifest = new Manifest();
To add an entry into a main section, get an instance of the Attributes class using the getMainAttributes() of Manifest class.
Add a name-value pair to it using its put() method.
The following code adds some attributes to the main section of a manifest object.
The attribute names are defined as constants in the Attributes.Name class.
For example, the constant Attributes.Name.MANIFEST_VERSION represents the Manifest-Version attribute name.
Manifest manifest = new Manifest(); Attributes mainAttribs = manifest.getMainAttributes(); mainAttribs.put(Attributes.Name.MANIFEST_VERSION, "1.0"); mainAttribs.put(Attributes.Name.MAIN_CLASS, "com.book2s.intro.Welcome"); mainAttribs.put(Attributes.Name.SEALED, "true");
Add the following individual entry to a manifest file:
Name: "com/book2s/archives/"
Sealed: false
The following code adds 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/book2s/archives/", attribs);
To add a manifest file to a JAR file, specify it in one of the constructors of the JarOutputStream class.
The following code creates a jar output stream to create a test.jar file with a Manifest object:
// Create a Manifest object Manifest manifest = new Manifest(); // Create a JarOutputStream with a Manifest object JarOutputStream jos = new JarOutputStream(new BufferedOutputStream( new FileOutputStream("test.jar")), manifest);