java.util.jar
Class JarFile

java.lang.Object
  extended byjava.util.zip.ZipFile
      extended byjava.util.jar.JarFile
All Implemented Interfaces:
ZipConstants

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.

Since:
1.2
Author:
David Connelly
See Also:
Manifest, ZipFile, JarEntry

Nested Class Summary
private  class JarFile.JarFileEntry
           
 
Nested classes inherited from class java.util.zip.ZipFile
 
Field Summary
private  boolean computedHasClassPathAttribute
           
private  boolean hasClassPathAttribute
           
private static String javaHome
           
private  JarVerifier jv
           
private  boolean jvInitialized
           
private static int[] lastOcc
           
private  Manifest man
           
private  JarEntry manEntry
           
static String MANIFEST_NAME
          The JAR manifest file name.
private  boolean manLoaded
           
private static int[] optoSft
           
private static char[] src
           
private  boolean verify
           
 
Fields inherited from class java.util.zip.ZipFile
CENATT, CENATX, CENCOM, CENCRC, CENDSK, CENEXT, CENFLG, CENHDR, CENHOW, CENLEN, CENNAM, CENOFF, CENSIG, CENSIZ, CENTIM, CENVEM, CENVER, ENDCOM, ENDHDR, ENDOFF, ENDSIG, ENDSIZ, ENDSUB, ENDTOT, EXTCRC, EXTHDR, EXTLEN, EXTSIG, EXTSIZ, LOCCRC, LOCEXT, LOCFLG, LOCHDR, LOCHOW, LOCLEN, LOCNAM, LOCSIG, LOCSIZ, LOCTIM, LOCVER, 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 entries()
          Returns an enumeration of the ZIP file entries.
private  byte[] getBytes(ZipEntry ze)
           
 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.
private  String[] getMetaInfEntryNames()
           
(package private)  boolean hasClassPathAttribute()
           
private  void initializeVerifier()
           
private  boolean isKnownToNotHaveClassPathAttribute()
           
private  void maybeInstantiateVerifier()
           
 
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

man

private Manifest man

manEntry

private JarEntry manEntry

manLoaded

private boolean manLoaded

jv

private JarVerifier jv

jvInitialized

private boolean jvInitialized

verify

private boolean verify

computedHasClassPathAttribute

private boolean computedHasClassPathAttribute

hasClassPathAttribute

private boolean hasClassPathAttribute

MANIFEST_NAME

public static final String MANIFEST_NAME
The JAR manifest file name.

See Also:
Constant Field Values

lastOcc

private static int[] lastOcc

optoSft

private static int[] optoSft

src

private static char[] src

javaHome

private static String javaHome
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 JarFile 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 JarFile 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 JarFile 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:
IOException

getMetaInfEntryNames

private String[] getMetaInfEntryNames()

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.
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
See Also:
ZipEntry

entries

public Enumeration entries()
Returns an enumeration of the ZIP file entries.

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

maybeInstantiateVerifier

private void maybeInstantiateVerifier()
                               throws IOException
Throws:
IOException

initializeVerifier

private void initializeVerifier()

getBytes

private byte[] getBytes(ZipEntry ze)
                 throws IOException
Throws:
IOException

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 format error has occurred
IOException - if an I/O error has occurred
SecurityException - if any of the JarFile entries are incorrectly signed.

hasClassPathAttribute

boolean hasClassPathAttribute()
                        throws IOException
Throws:
IOException

isKnownToNotHaveClassPathAttribute

private boolean isKnownToNotHaveClassPathAttribute()