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.

Constant Summary

String MANIFEST_NAME The JAR manifest file name.

Inherited Constant Summary

Public Constructor Summary

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.
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.

Public 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.
synchronized 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.

Inherited Method Summary

Constants

public static final String MANIFEST_NAME

The JAR manifest file name.

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

Public Constructors

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 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

public JarFile (String name, boolean verify)

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

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 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

public JarFile (File file, boolean verify)

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.

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 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

Public Methods

public Enumeration<JarEntry> entries ()

Returns an enumeration of the zip file entries.

Returns
  • an enumeration of the ZIP file entries

public ZipEntry getEntry (String name)

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

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

public synchronized InputStream getInputStream (ZipEntry ze)

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

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

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

public Manifest getManifest ()

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