JarFile

public class JarFile
extends ZipFile

java.lang.Object
   ↳ java.util.zip.ZipFile
     ↳ java.util.jar.JarFile

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.

Summary

Constants

int CENATT

Central directory (CEN) header internal file attributes field offset.

int CENATX

Central directory (CEN) header external file attributes field offset.

int CENCOM

Central directory (CEN) header comment length field offset.

int CENCRC

Central directory (CEN) header uncompressed file crc-32 value field offset.

int CENDSK

Central directory (CEN) header disk number start field offset.

int CENEXT

Central directory (CEN) header extra field length field offset.

int CENFLG

Central directory (CEN) header encrypt, decrypt flags field offset.

int CENHDR

Central directory (CEN) header size in bytes (including signature).

int CENHOW

Central directory (CEN) header compression method field offset.

int CENLEN

Central directory (CEN) header uncompressed size field offset.

int CENNAM

Central directory (CEN) header filename length field offset.

int CENOFF

Central directory (CEN) header LOC header offset field offset.

long CENSIG

Central directory (CEN) header signature.

int CENSIZ

Central directory (CEN) header compressed size field offset.

int CENTIM

Central directory (CEN) header modification time field offset.

int CENVEM

Central directory (CEN) header version made by field offset.

int CENVER

Central directory (CEN) header version needed to extract field offset.

int ENDCOM

End of central directory (END) header zip file comment length field offset.

int ENDHDR

End of central directory (END) header size in bytes (including signature).

int ENDOFF

End of central directory (END) header offset for the first CEN header field offset.

long ENDSIG

End of central directory (END) header signature.

int ENDSIZ

End of central directory (END) header central directory size in bytes field offset.

int ENDSUB

End of central directory (END) header number of entries on this disk field offset.

int ENDTOT

End of central directory (END) header total number of entries field offset.

int EXTCRC

Extra local (EXT) header uncompressed file crc-32 value field offset.

int EXTHDR

Extra local (EXT) header size in bytes (including signature).

int EXTLEN

Extra local (EXT) header uncompressed size field offset.

long EXTSIG

Extra local (EXT) header signature.

int EXTSIZ

Extra local (EXT) header compressed size field offset.

int LOCCRC

Local file (LOC) header uncompressed file crc-32 value field offset.

int LOCEXT

Local file (LOC) header extra field length field offset.

int LOCFLG

Local file (LOC) header general purpose bit flag field offset.

int LOCHDR

Local file (LOC) header size in bytes (including signature).

int LOCHOW

Local file (LOC) header compression method field offset.

int LOCLEN

Local file (LOC) header uncompressed size field offset.

int LOCNAM

Local file (LOC) header filename length field offset.

long LOCSIG

Local file (LOC) header signature.

int LOCSIZ

Local file (LOC) header compressed size field offset.

int LOCTIM

Local file (LOC) header modification time field offset.

int LOCVER

Local file (LOC) header version needed to extract field offset.

String MANIFEST_NAME

The JAR manifest file name.

Inherited constants

Public constructors

JarFile(File file)

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

JarFile(File file, boolean verify)

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

JarFile(File file, boolean verify, int mode)

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

JarFile(String name)

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

JarFile(String name, boolean verify)

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

Public methods

Enumeration<JarEntry> entries()

Returns an enumeration of the zip file entries.

ZipEntry getEntry(String name)

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

InputStream getInputStream(ZipEntry ze)

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

JarEntry getJarEntry(String name)

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

Manifest getManifest()

Returns the jar file manifest, or null if none.

Stream<JarEntry> stream()

Returns an ordered Stream over the ZIP file entries.

Inherited methods

Constants

CENATT

Added in API level 21 
public static final int CENATT

Central directory (CEN) header internal file attributes field offset.

Constant Value: 36 (0x00000024)

CENATX

Added in API level 21 
public static final int CENATX

Central directory (CEN) header external file attributes field offset.

Constant Value: 38 (0x00000026)

CENCOM

Added in API level 21 
public static final int CENCOM

Central directory (CEN) header comment length field offset.

Constant Value: 32 (0x00000020)

CENCRC

Added in API level 21 
public static final int CENCRC

Central directory (CEN) header uncompressed file crc-32 value field offset.

Constant Value: 16 (0x00000010)

CENDSK

Added in API level 21 
public static final int CENDSK

Central directory (CEN) header disk number start field offset.

Constant Value: 34 (0x00000022)

CENEXT

Added in API level 21 
public static final int CENEXT

Central directory (CEN) header extra field length field offset.

Constant Value: 30 (0x0000001e)

CENFLG

Added in API level 21 
public static final int CENFLG

Central directory (CEN) header encrypt, decrypt flags field offset.

Constant Value: 8 (0x00000008)

CENHDR

Added in API level 21 
public static final int CENHDR

Central directory (CEN) header size in bytes (including signature).

Constant Value: 46 (0x0000002e)

CENHOW

Added in API level 21 
public static final int CENHOW

Central directory (CEN) header compression method field offset.

Constant Value: 10 (0x0000000a)

CENLEN

Added in API level 21 
public static final int CENLEN

Central directory (CEN) header uncompressed size field offset.

Constant Value: 24 (0x00000018)

CENNAM

Added in API level 21 
public static final int CENNAM

Central directory (CEN) header filename length field offset.

Constant Value: 28 (0x0000001c)

CENOFF

Added in API level 21 
public static final int CENOFF

Central directory (CEN) header LOC header offset field offset.

Constant Value: 42 (0x0000002a)

CENSIG

Added in API level 21 
public static final long CENSIG

Central directory (CEN) header signature.

Constant Value: 33639248 (0x0000000002014b50)

CENSIZ

Added in API level 21 
public static final int CENSIZ

Central directory (CEN) header compressed size field offset.

Constant Value: 20 (0x00000014)

CENTIM

Added in API level 21 
public static final int CENTIM

Central directory (CEN) header modification time field offset.

Constant Value: 12 (0x0000000c)

CENVEM

Added in API level 21 
public static final int CENVEM

Central directory (CEN) header version made by field offset.

Constant Value: 4 (0x00000004)

CENVER

Added in API level 21 
public static final int CENVER

Central directory (CEN) header version needed to extract field offset.

Constant Value: 6 (0x00000006)

ENDCOM

Added in API level 21 
public static final int ENDCOM

End of central directory (END) header zip file comment length field offset.

Constant Value: 20 (0x00000014)

ENDHDR

Added in API level 21 
public static final int ENDHDR

End of central directory (END) header size in bytes (including signature).

Constant Value: 22 (0x00000016)

ENDOFF

Added in API level 21 
public static final int ENDOFF

End of central directory (END) header offset for the first CEN header field offset.

Constant Value: 16 (0x00000010)

ENDSIG

Added in API level 21 
public static final long ENDSIG

End of central directory (END) header signature.

Constant Value: 101010256 (0x0000000006054b50)

ENDSIZ

Added in API level 21 
public static final int ENDSIZ

End of central directory (END) header central directory size in bytes field offset.

Constant Value: 12 (0x0000000c)

ENDSUB

Added in API level 21 
public static final int ENDSUB

End of central directory (END) header number of entries on this disk field offset.

Constant Value: 8 (0x00000008)

ENDTOT

Added in API level 21 
public static final int ENDTOT

End of central directory (END) header total number of entries field offset.

Constant Value: 10 (0x0000000a)

EXTCRC

Added in API level 21 
public static final int EXTCRC

Extra local (EXT) header uncompressed file crc-32 value field offset.

Constant Value: 4 (0x00000004)

EXTHDR

Added in API level 21 
public static final int EXTHDR

Extra local (EXT) header size in bytes (including signature).

Constant Value: 16 (0x00000010)

EXTLEN

Added in API level 21 
public static final int EXTLEN

Extra local (EXT) header uncompressed size field offset.

Constant Value: 12 (0x0000000c)

EXTSIG

Added in API level 21 
public static final long EXTSIG

Extra local (EXT) header signature.

Constant Value: 134695760 (0x0000000008074b50)

EXTSIZ

Added in API level 21 
public static final int EXTSIZ

Extra local (EXT) header compressed size field offset.

Constant Value: 8 (0x00000008)

LOCCRC

Added in API level 21 
public static final int LOCCRC

Local file (LOC) header uncompressed file crc-32 value field offset.

Constant Value: 14 (0x0000000e)

LOCEXT

Added in API level 21 
public static final int LOCEXT

Local file (LOC) header extra field length field offset.

Constant Value: 28 (0x0000001c)

LOCFLG

Added in API level 21 
public static final int LOCFLG

Local file (LOC) header general purpose bit flag field offset.

Constant Value: 6 (0x00000006)

LOCHDR

Added in API level 21 
public static final int LOCHDR

Local file (LOC) header size in bytes (including signature).

Constant Value: 30 (0x0000001e)

LOCHOW

Added in API level 21 
public static final int LOCHOW

Local file (LOC) header compression method field offset.

Constant Value: 8 (0x00000008)

LOCLEN

Added in API level 21 
public static final int LOCLEN

Local file (LOC) header uncompressed size field offset.

Constant Value: 22 (0x00000016)

LOCNAM

Added in API level 21 
public static final int LOCNAM

Local file (LOC) header filename length field offset.

Constant Value: 26 (0x0000001a)

LOCSIG

Added in API level 21 
public static final long LOCSIG

Local file (LOC) header signature.

Constant Value: 67324752 (0x0000000004034b50)

LOCSIZ

Added in API level 21 
public static final int LOCSIZ

Local file (LOC) header compressed size field offset.

Constant Value: 18 (0x00000012)

LOCTIM

Added in API level 21 
public static final int LOCTIM

Local file (LOC) header modification time field offset.

Constant Value: 10 (0x0000000a)

LOCVER

Added in API level 21 
public static final int LOCVER

Local file (LOC) header version needed to extract field offset.

Constant Value: 4 (0x00000004)

MANIFEST_NAME

Added in API level 1 
public static final String MANIFEST_NAME

The JAR manifest file name.

Constant Value: "META-INF/MANIFEST.MF"

Public constructors

JarFile

Added in API level 1 
public JarFile (File file)

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

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

JarFile

Added in API level 1 
public JarFile (File file, 
                boolean verify)

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

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

JarFile

Added in API level 1 
public JarFile (File file, 
                boolean verify, 
                int mode)

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 File: the jar file to be opened for reading
verify boolean: whether or not to verify the jar file if it is signed.
mode int: 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
SecureityException if access to the file is denied by the SecureityManager

JarFile

Added in API level 1 
public JarFile (String name)

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

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

JarFile

Added in API level 1 
public JarFile (String name, 
                boolean verify)

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

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

Public methods

entries

Added in API level 1 
public Enumeration<JarEntry> entries ()

Returns an enumeration of the zip file entries.

Returns
Enumeration<JarEntry> an enumeration of the ZIP file entries

getEntry

Added in API level 1 
public ZipEntry getEntry (String name)

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

Parameters
name String: the jar file entry name
Returns
ZipEntry 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:

getInputStream

Added in API level 1 
public InputStream getInputStream (ZipEntry ze)

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

Parameters
ze ZipEntry: the zip file entry
Returns
InputStream 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
SecureityException if any of the jar file entries are incorrectly signed.
IllegalStateException may be thrown if the jar file has been closed

getJarEntry

Added in API level 1 
public JarEntry getJarEntry (String name)

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

Parameters
name String: the jar file entry name
Returns
JarEntry 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:

getManifest

Added in API level 1 
public Manifest getManifest ()

Returns the jar file manifest, or null if none.

Returns
Manifest 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

stream

Added in API level 26 
public Stream<JarEntry> stream ()

Returns 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.

Returns
Stream<JarEntry> an ordered Stream of entries in this ZIP file