Home » openjdk-7 » java » net » [javadoc | source]
abstract public class: JarURLConnection [javadoc | source]
A URL Connection to a Java ARchive (JAR) file or an entry in a JAR file.

The syntax of a JAR URL is:


for example:


Jar URLs should be used to refer to a JAR file or entries in a JAR file. The example above is a JAR URL which refers to a JAR entry. If the entry name is omitted, the URL refers to the whole JAR file: jar:http://www.foo.com/bar/baz.jar!/

Users should cast the generic URLConnection to a JarURLConnection when they know that the URL they created is a JAR URL, and they need JAR-specific functionality. For example:

URL url = new URL("jar:file:/home/duke/duke.jar!/");
JarURLConnection jarConnection = (JarURLConnection)url.openConnection();
Manifest manifest = jarConnection.getManifest();

JarURLConnection instances can only be used to read from JAR files. It is not possible to get a java.io.OutputStream to modify or write to the underlying JAR file using this class.


A Jar entry
A Jar file
A Jar directory

!/ is refered to as the separator.

When constructing a JAR url via new URL(context, spec), the following rules apply:

Field Summary
protected  URLConnection jarFileURLConnection    The connection to the JAR file URL, if the connection has been initiated. This should be set by connect. 
Fields inherited from java.net.URLConnection:
url,  doInput,  doOutput,  allowUserInteraction,  useCaches,  ifModifiedSince,  connected,  factory
 protected JarURLConnection(URL url) throws MalformedURLException 
    Creates the new JarURLConnection to the specified URL.
    url - the URL
    MalformedURLException - if no legal protocol could be found in a specification string or the string could not be parsed.
Method from java.net.JarURLConnection Summary:
getAttributes,   getCertificates,   getEntryName,   getJarEntry,   getJarFile,   getJarFileURL,   getMainAttributes,   getManifest
Methods from java.net.URLConnection:
addRequestProperty,   connect,   getAllowUserInteraction,   getConnectTimeout,   getContent,   getContent,   getContentEncoding,   getContentHandler,   getContentLength,   getContentLengthLong,   getContentType,   getDate,   getDefaultAllowUserInteraction,   getDefaultRequestProperty,   getDefaultUseCaches,   getDoInput,   getDoOutput,   getExpiration,   getFileNameMap,   getHeaderField,   getHeaderField,   getHeaderFieldDate,   getHeaderFieldInt,   getHeaderFieldKey,   getHeaderFieldLong,   getHeaderFields,   getIfModifiedSince,   getInputStream,   getLastModified,   getOutputStream,   getPermission,   getReadTimeout,   getRequestProperties,   getRequestProperty,   getURL,   getUseCaches,   guessContentTypeFromName,   guessContentTypeFromStream,   setAllowUserInteraction,   setConnectTimeout,   setContentHandlerFactory,   setDefaultAllowUserInteraction,   setDefaultRequestProperty,   setDefaultUseCaches,   setDoInput,   setDoOutput,   setFileNameMap,   setIfModifiedSince,   setReadTimeout,   setRequestProperty,   setUseCaches,   toString
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from java.net.JarURLConnection Detail:
 public Attributes getAttributes() throws IOException 
    Return the Attributes object for this connection if the URL for it points to a JAR file entry, null otherwise.
 public Certificate[] getCertificates() throws IOException 
    Return the Certificate object for this connection if the URL for it points to a JAR file entry, null otherwise. This method can only be called once the connection has been completely verified by reading from the input stream until the end of the stream has been reached. Otherwise, this method will return null
 public String getEntryName() 
    Return the entry name for this connection. This method returns null if the JAR file URL corresponding to this connection points to a JAR file and not a JAR file entry.
 public JarEntry getJarEntry() throws IOException 
    Return the JAR entry object for this connection, if any. This method returns null if the JAR file URL corresponding to this connection points to a JAR file and not a JAR file entry.
 abstract public JarFile getJarFile() throws IOException
    Return the JAR file for this connection.
 public URL getJarFileURL() 
    Returns the URL for the Jar file for this connection.
 public Attributes getMainAttributes() throws IOException 
    Returns the main Attributes for the JAR file for this connection.
 public Manifest getManifest() throws IOException 
    Returns the Manifest for this connection, or null if none.