Java™ Platform
Standard Ed. 6

java.util.jar
Class JarFile

java.lang.Object
  extended by java.util.zip.ZipFile
      extended by 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
See Also:
Constant Field Values

EXTSIG

public static final long EXTSIG
See Also:
Constant Field Values

CENSIG

public static final long CENSIG
See Also:
Constant Field Values

ENDSIG

public static final long ENDSIG
See Also:
Constant Field Values

LOCHDR

public static final int LOCHDR
See Also:
Constant Field Values

EXTHDR

public static final int EXTHDR
See Also:
Constant Field Values

CENHDR

public static final int CENHDR
See Also:
Constant Field Values

ENDHDR

public static final int ENDHDR
See Also:
Constant Field Values

LOCVER

public static final int LOCVER
See Also:
Constant Field Values

LOCFLG

public static final int LOCFLG
See Also:
Constant Field Values

LOCHOW

public static final int LOCHOW
See Also:
Constant Field Values

LOCTIM

public static final int LOCTIM
See Also:
Constant Field Values

LOCCRC

public static final int LOCCRC
See Also:
Constant Field Values

LOCSIZ

public static final int LOCSIZ
See Also:
Constant Field Values

LOCLEN

public static final int LOCLEN
See Also:
Constant Field Values

LOCNAM

public static final int LOCNAM
See Also:
Constant Field Values

LOCEXT

public static final int LOCEXT
See Also:
Constant Field Values

EXTCRC

public static final int EXTCRC
See Also:
Constant Field Values

EXTSIZ

public static final int EXTSIZ
See Also:
Constant Field Values

EXTLEN

public static final int EXTLEN
See Also:
Constant Field Values

CENVEM

public static final int CENVEM
See Also:
Constant Field Values

CENVER

public static final int CENVER
See Also:
Constant Field Values

CENFLG

public static final int CENFLG
See Also:
Constant Field Values

CENHOW

public static final int CENHOW
See Also:
Constant Field Values

CENTIM

public static final int CENTIM
See Also:
Constant Field Values

CENCRC

public static final int CENCRC
See Also:
Constant Field Values

CENSIZ

public static final int CENSIZ
See Also:
Constant Field Values

CENLEN

public static final int CENLEN
See Also:
Constant Field Values

CENNAM

public static final int CENNAM
See Also:
Constant Field Values

CENEXT

public static final int CENEXT
See Also:
Constant Field Values

CENCOM

public static final int CENCOM
See Also:
Constant Field Values

CENDSK

public static final int CENDSK
See Also:
Constant Field Values

CENATT

public static final int CENATT
See Also:
Constant Field Values

CENATX

public static final int CENATX
See Also:
Constant Field Values

CENOFF

public static final int CENOFF
See Also:
Constant Field Values

ENDSUB

public static final int ENDSUB
See Also:
Constant Field Values

ENDTOT

public static final int ENDTOT
See Also:
Constant Field Values

ENDSIZ

public static final int ENDSIZ
See Also:
Constant Field Values

ENDOFF

public static final int ENDOFF
See Also:
Constant Field Values

ENDCOM

public static final int ENDCOM
See Also:
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
Since:
1.3
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

Java™ Platform
Standard Ed. 6

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