JarURLConnection


JarURLConnection java.net

Java 1.2

This class is a specialized URLConnection that represents a connection to a jar : URL. A jar : URL is a compound URL that includes the URL of a JAR archive and, optionally , a reference to a file or directory within the JAR archive. The jar : URL syntax uses the ! character to separate the pathname of the JAR archive from the filename within the JAR archive. Note that a jar : URL contains a subprotocol that specifies the protocol that retrieves the JAR file itself. For example:

 jar:http://my.jar.com/my.jar!/       // The whole archive jar:file:/usr/java/lib/my.jar!/com/jar/          // A directory of the archive jar:ftp://ftp.jar.com/pub/my.jar!/com/jar/Jar.class // A file in the archive 

To obtain a JarURLConnection , define a URL object for a jar : URL, open a connection to it with openConnection( ) , and cast the returned URLConnection object to a JarURLConnection . The various methods defined by JarURLConnection allow you to read the manifest file of the JAR archive and look up attributes from that manifest for the archive as a whole or for individual entries in the archive. These methods make use of various classes from the java.util.jar package.

Figure 12-10. java.net.JarURLConnection

 public abstract class  JarURLConnection  extends URLConnection {  // Protected Constructors  protected  JarURLConnection  (URL  url  ) throws MalformedURLException;  // Public Instance Methods  public java.util.jar.Attributes  getAttributes  ( ) throws java.io.IOException;        public java.security.cert.Certificate[ ]  getCertificates  ( )  throws java.io.IOException;        public String  getEntryName  ( );        public java.util.jar.JarEntry  getJarEntry  ( ) throws java.io.IOException;        public abstract java.util.jar.JarFile  getJarFile  ( )  throws java.io.IOException;        public URL  getJarFileURL  ( );        public java.util.jar.Attributes  getMainAttributes  ( )  throws java.io.IOException;        public java.util.jar.Manifest  getManifest  ( ) throws java.io.IOException;  // Protected Instance Fields  protected URLConnection  jarFileURLConnection  ;   } 



Java In A Nutshell
Java In A Nutshell, 5th Edition
ISBN: 0596007736
EAN: 2147483647
Year: 2004
Pages: 1220

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