- All Implemented Interfaces:
Closeable
,AutoCloseable
public class JarFile extends ZipFile
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, and support for
processing multi-release jar files. The Manifest
can be used
to specify meta-information about the jar file and its entries.
A multi-release jar file is a jar file that
contains a manifest with a main attribute named "Multi-Release",
a set of "base" entries, some of which are public classes with public
or protected methods that comprise the public interface of the jar file,
and a set of "versioned" entries contained in subdirectories of the
"META-INF/versions" directory. The versioned entries are partitioned by the
major version of the Java platform. A versioned entry, with a version
n
, 8 < n
, in the "META-INF/versions/{n}" directory overrides
the base entry as well as any entry with a version number i
where
8 < i < n
.
By default, a JarFile
for a multi-release jar file is configured
to process the multi-release jar file as if it were a plain (unversioned) jar
file, and as such an entry name is associated with at most one base entry.
The JarFile
may be configured to process a multi-release jar file by
creating the JarFile
with the
JarFile(File, boolean, int, Runtime.Version)
constructor. The
Runtime.Version
object sets a maximum version used when searching for
versioned entries. When so configured, an entry name
can correspond with at most one base entry and zero or more versioned
entries. A search is required to associate the entry name with the latest
versioned entry whose version is less than or equal to the maximum version
(see getEntry(String)
).
Class loaders that utilize JarFile
to load classes from the
contents of JarFile
entries should construct the JarFile
by invoking the JarFile(File, boolean, int, Runtime.Version)
constructor with the value Runtime.version()
assigned to the last
argument. This assures that classes compatible with the major
version of the running JVM are loaded from multi-release jar files.
If the verify
flag is on when opening a signed jar file, the content
of the jar entry is verified against the signature embedded inside the manifest
that is associated with its path name
. For a
multi-release jar file, the content of a versioned entry is verfieid against
its own signature and JarEntry.getCodeSigners()
returns its own signers.
Please note that the verification process does not include validating the
signer's certificate. A caller should inspect the return value of
JarEntry.getCodeSigners()
to further determine if the signature
can be trusted.
Unless otherwise noted, passing a null
argument to a constructor
or method in this class will cause a NullPointerException
to be
thrown.
- Implementation Note:
- If the API can not be used to configure a
JarFile
(e.g. to override the configuration of a compiled application or library), twoSystem
properties are available.-
jdk.util.jar.version
can be assigned a value that is theString
representation of a non-negative integer<= Runtime.version().feature()
. The value is used to set the effective runtime version to something other than the default value obtained by evaluatingRuntime.version().feature()
. The effective runtime version is the version that theJarFile(File, boolean, int, Runtime.Version)
constructor uses when the value of the last argument isJarFile.runtimeVersion()
. -
jdk.util.jar.enableMultiRelease
can be assigned one of the threeString
values true, false, or force. The value true, the default value, enables multi-release jar file processing. The value false disables multi-release jar processing, ignoring the "Multi-Release" manifest attribute, and the versioned directories in a multi-release jar file if they exist. Furthermore, the methodisMultiRelease()
returns false. The value force causes theJarFile
to be initialized to runtime versioning after construction. It effectively does the same as this code:(new JarFile(File, boolean, int, JarFile.runtimeVersion())
.
-
- Since:
- 1.2
- See Also:
Manifest
,ZipFile
,JarEntry
-
Field Summary
Fields Modifier and Type Field Description 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 declared in class java.util.zip.ZipFile
OPEN_DELETE, OPEN_READ
-
Constructor Summary
Constructors Constructor Description JarFile(File file)
Creates a newJarFile
to read from the specifiedFile
object.JarFile(File file, boolean verify)
Creates a newJarFile
to read from the specifiedFile
object.JarFile(File file, boolean verify, int mode)
Creates a newJarFile
to read from the specifiedFile
object in the specified mode.JarFile(File file, boolean verify, int mode, Runtime.Version version)
Creates a newJarFile
to read from the specifiedFile
object in the specified mode.JarFile(String name)
Creates a newJarFile
to read from the specified filename
.JarFile(String name, boolean verify)
Creates a newJarFile
to read from the specified filename
. -
Method Summary
Modifier and Type Method Description static Runtime.Version
baseVersion()
Returns the version that represents the unversioned configuration of a multi-release jar file.Enumeration<JarEntry>
entries()
Returns an enumeration of the jar file entries.ZipEntry
getEntry(String name)
Returns theZipEntry
for the given base entry name ornull
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 theJarEntry
for the given base entry name ornull
if not found.Manifest
getManifest()
Returns the jar file manifest, ornull
if none.Runtime.Version
getVersion()
Returns the maximum version used when searching for versioned entries.boolean
isMultiRelease()
Indicates whether or not this jar file is a multi-release jar file.static Runtime.Version
runtimeVersion()
Returns the version that represents the effective runtime versioned configuration of a multi-release jar file.Stream<JarEntry>
stream()
Returns an orderedStream
over the jar file entries.Stream<JarEntry>
versionedStream()
Returns aStream
of the versioned jar file entries.Methods declared in class java.util.zip.ZipFile
close, getComment, getName, size
-
Field Details
-
MANIFEST_NAME
The JAR manifest file name.- See Also:
- Constant Field Values
-
LOCSIG
static final long LOCSIG- See Also:
- Constant Field Values
-
EXTSIG
static final long EXTSIG- See Also:
- Constant Field Values
-
CENSIG
static final long CENSIG- See Also:
- Constant Field Values
-
ENDSIG
static final long ENDSIG- See Also:
- Constant Field Values
-
LOCHDR
static final int LOCHDR- See Also:
- Constant Field Values
-
EXTHDR
static final int EXTHDR- See Also:
- Constant Field Values
-
CENHDR
static final int CENHDR- See Also:
- Constant Field Values
-
ENDHDR
static final int ENDHDR- See Also:
- Constant Field Values
-
LOCVER
static final int LOCVER- See Also:
- Constant Field Values
-
LOCFLG
static final int LOCFLG- See Also:
- Constant Field Values
-
LOCHOW
static final int LOCHOW- See Also:
- Constant Field Values
-
LOCTIM
static final int LOCTIM- See Also:
- Constant Field Values
-
LOCCRC
static final int LOCCRC- See Also:
- Constant Field Values
-
LOCSIZ
static final int LOCSIZ- See Also:
- Constant Field Values
-
LOCLEN
static final int LOCLEN- See Also:
- Constant Field Values
-
LOCNAM
static final int LOCNAM- See Also:
- Constant Field Values
-
LOCEXT
static final int LOCEXT- See Also:
- Constant Field Values
-
EXTCRC
static final int EXTCRC- See Also:
- Constant Field Values
-
EXTSIZ
static final int EXTSIZ- See Also:
- Constant Field Values
-
EXTLEN
static final int EXTLEN- See Also:
- Constant Field Values
-
CENVEM
static final int CENVEM- See Also:
- Constant Field Values
-
CENVER
static final int CENVER- See Also:
- Constant Field Values
-
CENFLG
static final int CENFLG- See Also:
- Constant Field Values
-
CENHOW
static final int CENHOW- See Also:
- Constant Field Values
-
CENTIM
static final int CENTIM- See Also:
- Constant Field Values
-
CENCRC
static final int CENCRC- See Also:
- Constant Field Values
-
CENSIZ
static final int CENSIZ- See Also:
- Constant Field Values
-
CENLEN
static final int CENLEN- See Also:
- Constant Field Values
-
CENNAM
static final int CENNAM- See Also:
- Constant Field Values
-
CENEXT
static final int CENEXT- See Also:
- Constant Field Values
-
CENCOM
static final int CENCOM- See Also:
- Constant Field Values
-
CENDSK
static final int CENDSK- See Also:
- Constant Field Values
-
CENATT
static final int CENATT- See Also:
- Constant Field Values
-
CENATX
static final int CENATX- See Also:
- Constant Field Values
-
CENOFF
static final int CENOFF- See Also:
- Constant Field Values
-
ENDSUB
static final int ENDSUB- See Also:
- Constant Field Values
-
ENDTOT
static final int ENDTOT- See Also:
- Constant Field Values
-
ENDSIZ
static final int ENDSIZ- See Also:
- Constant Field Values
-
ENDOFF
static final int ENDOFF- See Also:
- Constant Field Values
-
ENDCOM
static final int ENDCOM- See Also:
- Constant Field Values
-
-
Constructor Details
-
JarFile
Creates a newJarFile
to read from the specified filename
. TheJarFile
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 occurredSecurityException
- if access to the file is denied by the SecurityManager
-
JarFile
Creates a newJarFile
to read from the specified filename
.- Parameters:
name
- the name of the jar file to be opened for readingverify
- whether or not to verify the jar file if it is signed.- Throws:
IOException
- if an I/O error has occurredSecurityException
- if access to the file is denied by the SecurityManager
-
JarFile
Creates a newJarFile
to read from the specifiedFile
object. TheJarFile
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 occurredSecurityException
- if access to the file is denied by the SecurityManager
-
JarFile
Creates a newJarFile
to read from the specifiedFile
object.- Parameters:
file
- the jar file to be opened for readingverify
- whether or not to verify the jar file if it is signed.- Throws:
IOException
- if an I/O error has occurredSecurityException
- if access to the file is denied by the SecurityManager.
-
JarFile
Creates a newJarFile
to read from the specifiedFile
object in the specified mode. The mode argument must be eitherOPEN_READ
orOPEN_READ | OPEN_DELETE
.- Parameters:
file
- the jar file to be opened for readingverify
- 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 occurredIllegalArgumentException
- if themode
argument is invalidSecurityException
- if access to the file is denied by the SecurityManager- Since:
- 1.3
-
JarFile
Creates a newJarFile
to read from the specifiedFile
object in the specified mode. The mode argument must be eitherOPEN_READ
orOPEN_READ | OPEN_DELETE
. The version argument, after being converted to a canonical form, is used to configure theJarFile
for processing multi-release jar files.The canonical form derived from the version parameter is
Runtime.Version.parse(Integer.toString(n))
wheren
isMath.max(version.feature(), JarFile.baseVersion().feature())
.- Parameters:
file
- the jar file to be opened for readingverify
- whether or not to verify the jar file if it is signed.mode
- the mode in which the file is to be openedversion
- specifies the release version for a multi-release jar file- Throws:
IOException
- if an I/O error has occurredIllegalArgumentException
- if themode
argument is invalidSecurityException
- if access to the file is denied by the SecurityManagerNullPointerException
- ifversion
isnull
- Since:
- 9
-
-
Method Details
-
baseVersion
Returns the version that represents the unversioned configuration of a multi-release jar file.- Returns:
- the version that represents the unversioned configuration
- Since:
- 9
-
runtimeVersion
Returns the version that represents the effective runtime versioned configuration of a multi-release jar file.By default the feature version number of the returned
Version
will be equal to the feature version number ofRuntime.version()
. However, if thejdk.util.jar.version
property is set, the returnedVersion
is derived from that property and feature version numbers may not be equal.- Returns:
- the version that represents the runtime versioned configuration
- Since:
- 9
-
getVersion
Returns the maximum version used when searching for versioned entries.If this
JarFile
is not a multi-release jar file or is not configured to be processed as such, then the version returned will be the same as that returned frombaseVersion()
.- Returns:
- the maximum version
- Since:
- 9
-
isMultiRelease
public final boolean isMultiRelease()Indicates whether or not this jar file is a multi-release jar file.- Returns:
- true if this JarFile is a multi-release jar file
- Since:
- 9
-
getManifest
Returns the jar file manifest, ornull
if none.- Returns:
- the jar file manifest, or
null
if none - Throws:
IllegalStateException
- may be thrown if the jar file has been closedIOException
- if an I/O error has occurred
-
getJarEntry
Returns theJarEntry
for the given base entry name ornull
if not found.If this
JarFile
is a multi-release jar file and is configured to be processed as such, then a search is performed to find and return aJarEntry
that is the latest versioned entry associated with the given entry name. The returnedJarEntry
is the versioned entry corresponding to the given base entry name prefixed with the string"META-INF/versions/{n}/"
, for the largest value ofn
for which an entry exists. If such a versioned entry does not exist, then theJarEntry
for the base entry is returned, otherwisenull
is returned if no entries are found. The initial value for the versionn
is the maximum version as returned by the methodgetVersion()
.- Implementation Requirements:
- This implementation invokes
getEntry(String)
. - Parameters:
name
- the jar file entry name- Returns:
- the
JarEntry
for the given entry name, or the versioned entry name, ornull
if not found - Throws:
IllegalStateException
- may be thrown if the jar file has been closed- See Also:
JarEntry
-
getEntry
Returns theZipEntry
for the given base entry name ornull
if not found.If this
JarFile
is a multi-release jar file and is configured to be processed as such, then a search is performed to find and return aZipEntry
that is the latest versioned entry associated with the given entry name. The returnedZipEntry
is the versioned entry corresponding to the given base entry name prefixed with the string"META-INF/versions/{n}/"
, for the largest value ofn
for which an entry exists. If such a versioned entry does not exist, then theZipEntry
for the base entry is returned, otherwisenull
is returned if no entries are found. The initial value for the versionn
is the maximum version as returned by the methodgetVersion()
.- Overrides:
getEntry
in classZipFile
- Implementation Requirements:
- This implementation may return a versioned entry for the requested name even if there is not a corresponding base entry. This can occur if there is a private or package-private versioned entry that matches. If a subclass overrides this method, assure that the override method invokes
super.getEntry(name)
to obtain all versioned entries. - Parameters:
name
- the jar file entry name- Returns:
- the
ZipEntry
for the given entry name or the versioned entry name ornull
if not found - Throws:
IllegalStateException
- may be thrown if the jar file has been closed- See Also:
ZipEntry
-
entries
Returns an enumeration of the jar file entries.- Overrides:
entries
in classZipFile
- Returns:
- an enumeration of the jar file entries
- Throws:
IllegalStateException
- may be thrown if the jar file has been closed
-
stream
Returns an orderedStream
over the jar file entries. Entries appear in theStream
in the order they appear in the central directory of the jar file.- Overrides:
stream
in classZipFile
- Returns:
- an ordered
Stream
of entries in this jar file - Throws:
IllegalStateException
- if the jar file has been closed- Since:
- 1.8
-
versionedStream
Returns aStream
of the versioned jar file entries.If this
JarFile
is a multi-release jar file and is configured to be processed as such, then an entry in the stream is the latest versioned entry associated with the corresponding base entry name. The maximum version of the latest versioned entry is the version returned bygetVersion()
. The returned stream may include an entry that only exists as a versioned entry. If the jar file is not a multi-release jar file or theJarFile
is not configured for processing a multi-release jar file, this method returns the same stream thatstream()
returns.- Returns:
- stream of versioned entries
- Since:
- 10
-
getInputStream
Returns an input stream for reading the contents of the specified zip file entry.- Overrides:
getInputStream
in classZipFile
- 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 occurredIOException
- if an I/O error has occurredSecurityException
- if any of the jar file entries are incorrectly signed.IllegalStateException
- may be thrown if the jar file has been closed
-