public abstract class JarURLConnection extends URLConnection
A URL Connection to a Java ARchive (JAR) file or an entry in a JAR file.
The syntax of a JAR URL is:
jar:<url>!/{entry}
for example:
jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class
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 OutputStream
to modify or write to the underlying JAR file using this class.
Examples:
jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class
jar:http://www.foo.com/bar/baz.jar!/
jar:http://www.foo.com/bar/baz.jar!/COM/foo/
!/
is referred to as the separator.
When constructing a JAR url via new URL(context, spec)
, the following rules apply:
Examples:
URL
, URLConnection
, JarFile
, JarInputStream
, Manifest
, ZipEntry
protected URLConnection jarFileURLConnection
The connection to the JAR file URL, if the connection has been initiated. This should be set by connect.
protected JarURLConnection(URL url) throws MalformedURLException
Creates the new JarURLConnection to the specified URL.
url
- the URLMalformedURLException
- if no legal protocol could be found in a specification string or the string could not be parsed.public URL getJarFileURL()
Returns the URL for the Jar file for this connection.
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 abstract JarFile getJarFile() throws IOException
Return the JAR file for this connection.
IOException
- if an IOException occurs while trying to connect to the JAR file for this connection.URLConnection.connect()
public Manifest getManifest() throws IOException
Returns the Manifest for this connection, or null if none.
IOException
- if getting the JAR file for this connection causes an IOException to be thrown.getJarFile()
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.
IOException
- if getting the JAR file for this connection causes an IOException to be thrown.getJarFile()
, getJarEntry()
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.
IOException
- if getting the JAR entry causes an IOException to be thrown.getJarEntry()
public Attributes getMainAttributes() throws IOException
Returns the main Attributes for the JAR file for this connection.
IOException
- if getting the manifest causes an IOException to be thrown.getJarFile()
, getManifest()
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
IOException
- if getting the JAR entry causes an IOException to be thrown.getJarEntry()
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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