JarEntry

AI-generated Key Takeaways

• JarEntry represents an entry within a JAR file, extending the functionality of ZipEntry.

• It provides methods to access entry-specific information like Manifest attributes, certificates, and code signers.

• Constructors allow creation from a filename, a ZipEntry, or another JarEntry.

• Inherits methods from ZipEntry for managing entry metadata like size, compression, timestamps, and comments.

• getAttributes, getCertificates, and getCodeSigners provide access to security and manifest details.

public class JarEntry extends ZipEntry

This class is used to represent a JAR file entry.

Inherited Constant Summary

From class java.util.zip.ZipEntry

int	CENATT
int	CENATX
int	CENCOM
int	CENCRC
int	CENDSK
int	CENEXT
int	CENFLG
int	CENHDR
int	CENHOW
int	CENLEN
int	CENNAM
int	CENOFF
long	CENSIG
int	CENSIZ
int	CENTIM
int	CENVEM
int	CENVER
int	DEFLATED	Compression method for compressed (deflated) entries.
long	DOSTIME_BEFORE_1980	DOS time constant for representing timestamps before 1980.
int	ENDCOM
int	ENDHDR
int	ENDOFF
long	ENDSIG
int	ENDSIZ
int	ENDSUB
int	ENDTOT
int	EXTCRC
int	EXTHDR
int	EXTLEN
long	EXTSIG
int	EXTSIZ
int	LOCCRC
int	LOCEXT
int	LOCFLG
int	LOCHDR
int	LOCHOW
int	LOCLEN
int	LOCNAM
long	LOCSIG
int	LOCSIZ
int	LOCTIM
int	LOCVER
int	STORED	Compression method for uncompressed entries.

Public Constructor Summary

	JarEntry(String name) Creates a new JarEntry for the specified JAR file entry name.
	JarEntry(ZipEntry ze) Creates a new JarEntry with fields taken from the specified ZipEntry object.
	JarEntry(JarEntry je) Creates a new JarEntry with fields taken from the specified JarEntry object.

Public Method Summary

Attributes	getAttributes() Returns the Manifest Attributes for this entry, or null if none.
Certificate[]	getCertificates() Returns the Certificate objects for this entry, or null if none.
CodeSigner[]	getCodeSigners() Returns the CodeSigner objects for this entry, or null if none.

Inherited Method Summary

From class java.util.zip.ZipEntry

Object	clone() Returns a copy of this entry.
String	getComment() Returns the comment string for the entry.
long	getCompressedSize() Returns the size of the compressed entry data.
long	getCrc() Returns the CRC-32 checksum of the uncompressed entry data.
FileTime	getCreationTime() Returns the creation time of the entry.
byte[]	getExtra() Returns the extra field data for the entry.
FileTime	getLastAccessTime() Returns the last access time of the entry.
FileTime	getLastModifiedTime() Returns the last modification time of the entry.
int	getMethod() Returns the compression method of the entry.
String	getName() Returns the name of the entry.
long	getSize() Returns the uncompressed size of the entry data.
long	getTime() Returns the last modification time of the entry.
int	hashCode() Returns the hash code value for this entry.
boolean	isDirectory() Returns true if this is a directory entry.
void	setComment(String comment) Sets the optional comment string for the entry.
void	setCompressedSize(long csize) Sets the size of the compressed entry data.
void	setCrc(long crc) Sets the CRC-32 checksum of the uncompressed entry data.
ZipEntry	setCreationTime(FileTime time) Sets the creation time of the entry.
void	setExtra(byte[] extra) Sets the optional extra field data for the entry.
ZipEntry	setLastAccessTime(FileTime time) Sets the last access time of the entry.
ZipEntry	setLastModifiedTime(FileTime time) Sets the last modification time of the entry.
void	setMethod(int method) Sets the compression method for the entry.
void	setSize(long size) Sets the uncompressed size of the entry data.
void	setTime(long time) Sets the last modification time of the entry.
String	toString() Returns a string representation of the ZIP entry.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public JarEntry (String name)

Creates a new JarEntry for the specified JAR file entry name.

Parameters

name	the JAR file entry name

Throws

NullPointerException	if the entry name is null
IllegalArgumentException	if the entry name is longer than 0xFFFF bytes.

public JarEntry (ZipEntry ze)

Creates a new JarEntry with fields taken from the specified ZipEntry object.

Parameters

ze	the ZipEntry object to create the JarEntry from

public JarEntry (JarEntry je)

Creates a new JarEntry with fields taken from the specified JarEntry object.

Parameters

je	the JarEntry to copy

Public Methods

public Attributes getAttributes ()

Returns the Manifest Attributes for this entry, or null if none.

Returns

• the Manifest Attributes for this entry, or null if none

Throws

IOException	if an I/O error has occurred

public Certificate[] getCertificates ()

Returns the Certificate objects for this entry, or null if none. This method can only be called once the JarEntry has been completely verified by reading from the entry input stream until the end of the stream has been reached. Otherwise, this method will return null.

The returned certificate array comprises all the signer certificates that were used to verify this entry. Each signer certificate is followed by its supporting certificate chain (which may be empty). Each signer certificate and its supporting certificate chain are ordered bottom-to-top (i.e., with the signer certificate first and the (root) certificate authority last).

Returns

• the Certificate objects for this entry, or null if none.

public CodeSigner[] getCodeSigners ()

Returns the CodeSigner objects for this entry, or null if none. This method can only be called once the JarEntry has been completely verified by reading from the entry input stream until the end of the stream has been reached. Otherwise, this method will return null.

The returned array comprises all the code signers that have signed this entry.

Returns

• the CodeSigner objects for this entry, or null if none.