JarURLConnection getMainAttributes() in Java

getMainAttributes(): This method is available in the java.net.JarURLConnection class of Java.

Syntax:

Attributes java.net.JarURLConnection.getMainAttributes() throws IOException

This method returns the main Attributes for the JAR file for this connection.

Parameters: NA

Returns: the main Attributes for the JAR file for this connection.

Throws:

1. IOException - if getting the manifest causes anIOException to be thrown.

Approach

Java

package com.JarURLConnection;

import java.net.JarURLConnection;
import java.net.URL;

public class JarURLConnectiongetMainAttributes {

    private final static String JAR_URL = "jar:file:/D:/testClass.jar!/";

    public static void main(String[] args) throws Exception {

        URL FileSysUrl = new URL(JAR_URL);

        JarURLConnection jarURLConn = 
                      (JarURLConnection) FileSysUrl.openConnection();

        System.out.println(jarURLConn.getMainAttributes());

    }
}

Output:

java.util.jar.Attributes@49f83991

Some other methods of JarURLConnection class

getAttributes(): This method returns the Attributes object for this connection if its URL points to a JAR file entry, null otherwise.

getCertificates(): This method returns the Certificate objects for this connection if the URL for it points to a JAR file entry, null otherwise.

getEntryName(): This method returns the entry name for this connection.

getJarEntry(): This method returns the JAR entry object for this connection if any. 

getJarFile(): This method returns the JAR file for this connection.

getJarFileURL(): This method returns the URL for the Jar file for this connection.

getMainAttributes(): This method returns the main Attributes for the JAR file for this connection.

getManifest(): This method returns the Manifest for this connection, or null if none.