W3cubDocs

/OpenJDK 8

Class JarFile

All Implemented Interfaces:
Closeable, AutoCloseable 
public class JarFile
extends ZipFile

The JarFile class is used to read the contents of a jar file from any file that can be opened with java.io.RandomAccessFile. It extends the class java.util.zip.ZipFile with support for reading an optional Manifest entry. The Manifest can be used to specify meta-information about the jar file and its entries.

Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a NullPointerException to be thrown. If the verify flag is on when opening a signed jar file, the content of the file is verified against its signature embedded inside the file. Please note that the verification process does not include validating the signer's certificate. A caller should inspect the return value of JarEntry.getCodeSigners() to further determine if the signature can be trusted.

Since:
1.2
See Also:
Manifest, ZipFile, JarEntry

Fields

MANIFEST_NAME

public static final String MANIFEST_NAME

The JAR manifest file name.

LOCSIG

public static final long LOCSIG

EXTSIG

public static final long EXTSIG

CENSIG

public static final long CENSIG

ENDSIG

public static final long ENDSIG

LOCHDR

public static final int LOCHDR

EXTHDR

public static final int EXTHDR

CENHDR

public static final int CENHDR

ENDHDR

public static final int ENDHDR

LOCVER

public static final int LOCVER

LOCFLG

public static final int LOCFLG

LOCHOW

public static final int LOCHOW

LOCTIM

public static final int LOCTIM

LOCCRC

public static final int LOCCRC

LOCSIZ

public static final int LOCSIZ

LOCLEN

public static final int LOCLEN

LOCNAM

public static final int LOCNAM

LOCEXT

public static final int LOCEXT

EXTCRC

public static final int EXTCRC

EXTSIZ

public static final int EXTSIZ

EXTLEN

public static final int EXTLEN

CENVEM

public static final int CENVEM

CENVER

public static final int CENVER

CENFLG

public static final int CENFLG

CENHOW

public static final int CENHOW

CENTIM

public static final int CENTIM

CENCRC

public static final int CENCRC

CENSIZ

public static final int CENSIZ

CENLEN

public static final int CENLEN

CENNAM

public static final int CENNAM

CENEXT

public static final int CENEXT

CENCOM

public static final int CENCOM

CENDSK

public static final int CENDSK

CENATT

public static final int CENATT

CENATX

public static final int CENATX

CENOFF

public static final int CENOFF

ENDSUB

public static final int ENDSUB

ENDTOT

public static final int ENDTOT

ENDSIZ

public static final int ENDSIZ

ENDOFF

public static final int ENDOFF

ENDCOM

public static final int ENDCOM

Constructors

JarFile

public JarFile(String name)
        throws IOException

Creates a new JarFile to read from the specified file name. The JarFile will be verified if it is signed.

Parameters:
name - the name of the jar file to be opened for reading
Throws:
IOException - if an I/O error has occurred
SecurityException - if access to the file is denied by the SecurityManager

JarFile

public JarFile(String name,
               boolean verify)
        throws IOException

Creates a new JarFile to read from the specified file name.

Parameters:
name - the name of the jar file to be opened for reading
verify - whether or not to verify the jar file if it is signed.
Throws:
IOException - if an I/O error has occurred
SecurityException - if access to the file is denied by the SecurityManager

JarFile

public JarFile(File file)
        throws IOException

Creates a new JarFile to read from the specified File object. The JarFile will be verified if it is signed.

Parameters:
file - the jar file to be opened for reading
Throws:
IOException - if an I/O error has occurred
SecurityException - if access to the file is denied by the SecurityManager

JarFile

public JarFile(File file,
               boolean verify)
        throws IOException

Creates a new JarFile to read from the specified File object.

Parameters:
file - the jar file to be opened for reading
verify - whether or not to verify the jar file if it is signed.
Throws:
IOException - if an I/O error has occurred
SecurityException - if access to the file is denied by the SecurityManager.

JarFile

public JarFile(File file,
               boolean verify,
               int mode)
        throws IOException

Creates a new JarFile to read from the specified File object in the specified mode. The mode argument must be either OPEN_READ or OPEN_READ | OPEN_DELETE.

Parameters:
file - the jar file to be opened for reading
verify - whether or not to verify the jar file if it is signed.
mode - the mode in which the file is to be opened
Throws:
IOException - if an I/O error has occurred
IllegalArgumentException - if the mode argument is invalid
SecurityException - if access to the file is denied by the SecurityManager
Since:
1.3

Methods

getManifest

public Manifest getManifest()
                     throws IOException

Returns the jar file manifest, or null if none.

Returns:
the jar file manifest, or null if none
Throws:
IllegalStateException - may be thrown if the jar file has been closed
IOException - if an I/O error has occurred

getJarEntry

public JarEntry getJarEntry(String name)

Returns the JarEntry for the given entry name or null if not found.

Parameters:
name - the jar file entry name
Returns:
the JarEntry for the given entry name or null if not found.
Throws:
IllegalStateException - may be thrown if the jar file has been closed
See Also:
JarEntry

getEntry

public ZipEntry getEntry(String name)

Returns the ZipEntry for the given entry name or null if not found.

Overrides:
getEntry in class ZipFile
Parameters:
name - the jar file entry name
Returns:
the ZipEntry for the given entry name or null if not found
Throws:
IllegalStateException - may be thrown if the jar file has been closed
See Also:
ZipEntry

entries

public Enumeration<JarEntry> entries()

Returns an enumeration of the zip file entries.

Overrides:
entries in class ZipFile
Returns:
an enumeration of the ZIP file entries

stream

public Stream<JarEntry> stream()

Description copied from class: ZipFile

Return an ordered Stream over the ZIP file entries. Entries appear in the Stream in the order they appear in the central directory of the ZIP file.

Overrides:
stream in class ZipFile
Returns:
an ordered Stream of entries in this ZIP file

getInputStream

public InputStream getInputStream(ZipEntry ze)
                           throws IOException

Returns an input stream for reading the contents of the specified zip file entry.

Overrides:
getInputStream in class ZipFile
Parameters:
ze - the zip file entry
Returns:
an input stream for reading the contents of the specified zip file entry
Throws:
ZipException - if a zip file format error has occurred
IOException - if an I/O error has occurred
SecurityException - if any of the jar file entries are incorrectly signed.
IllegalStateException - may be thrown if the jar file has been closed

© 1993–2017, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.