java.util.jar
Class JarFile

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

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.

Since:

1.2

See Also:

Manifest, ZipFile, JarEntry

Field Summary

static int	CENATT
static int	CENATX
static int	CENCOM
static int	CENCRC
static int	CENDSK
static int	CENEXT
static int	CENFLG
static int	CENHDR
static int	CENHOW
static int	CENLEN
static int	CENNAM
static int	CENOFF
static long	CENSIG
static int	CENSIZ
static int	CENTIM
static int	CENVEM
static int	CENVER
static int	ENDCOM
static int	ENDHDR
static int	ENDOFF
static long	ENDSIG
static int	ENDSIZ
static int	ENDSUB
static int	ENDTOT
static int	EXTCRC
static int	EXTHDR
static int	EXTLEN
static long	EXTSIG
static int	EXTSIZ
static int	LOCCRC
static int	LOCEXT
static int	LOCFLG
static int	LOCHDR
static int	LOCHOW
static int	LOCLEN
static int	LOCNAM
static long	LOCSIG
static int	LOCSIZ
static int	LOCTIM
static int	LOCVER
static String	MANIFEST_NAME The JAR manifest file name.

Fields inherited from class java.util.zip.ZipFile

OPEN_DELETE, OPEN_READ

Constructor Summary

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.

Method Summary

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.

Methods inherited from class java.util.zip.ZipFile

close, finalize, getName, size

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MANIFEST_NAME

public static final String MANIFEST_NAME

The JAR manifest file name.

See Also:

Constant Field Values

LOCSIG

public static final long LOCSIG

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Constant Field Values

EXTSIG

public static final long EXTSIG

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Constant Field Values

CENSIG

public static final long CENSIG

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Constant Field Values

ENDSIG

public static final long ENDSIG

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Constant Field Values

LOCHDR

public static final int LOCHDR

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EXTHDR

public static final int EXTHDR

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Constant Field Values

CENHDR

public static final int CENHDR

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Constant Field Values

ENDHDR

public static final int ENDHDR

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Constant Field Values

LOCVER

public static final int LOCVER

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Constant Field Values

LOCFLG

public static final int LOCFLG

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Constant Field Values

LOCHOW

public static final int LOCHOW

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Constant Field Values

LOCTIM

public static final int LOCTIM

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Constant Field Values

LOCCRC

public static final int LOCCRC

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Constant Field Values

LOCSIZ

public static final int LOCSIZ

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LOCLEN

public static final int LOCLEN

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LOCNAM

public static final int LOCNAM

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Constant Field Values

LOCEXT

public static final int LOCEXT

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Constant Field Values

EXTCRC

public static final int EXTCRC

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Constant Field Values

EXTSIZ

public static final int EXTSIZ

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Constant Field Values

EXTLEN

public static final int EXTLEN

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Constant Field Values

CENVEM

public static final int CENVEM

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Constant Field Values

CENVER

public static final int CENVER

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Constant Field Values

CENFLG

public static final int CENFLG

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Constant Field Values

CENHOW

public static final int CENHOW

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Constant Field Values

CENTIM

public static final int CENTIM

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Constant Field Values

CENCRC

public static final int CENCRC

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Constant Field Values

CENSIZ

public static final int CENSIZ

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Constant Field Values

CENLEN

public static final int CENLEN

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Constant Field Values

CENNAM

public static final int CENNAM

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CENEXT

public static final int CENEXT

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CENCOM

public static final int CENCOM

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CENDSK

public static final int CENDSK

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CENATT

public static final int CENATT

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CENATX

public static final int CENATX

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CENOFF

public static final int CENOFF

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ENDSUB

public static final int ENDSUB

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ENDTOT

public static final int ENDTOT

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ENDSIZ

public static final int ENDSIZ

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ENDOFF

public static final int ENDOFF

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ENDCOM

public static final int ENDCOM

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Constant Field Values

Constructor Detail

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

Method Detail

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

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

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