Class JarFile
- All Implemented Interfaces:
- Closeable,- AutoCloseable
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 verified 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 aJarFile(e.g. to override the configuration of a compiled application or library), twoSystemproperties are available.- 
 jdk.util.jar.versioncan be assigned a value that is theStringrepresentation 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().
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 jdk.util.jar.enableMultiReleasecan be assigned one of the threeStringvalues 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 theJarFileto be initialized to runtime versioning after construction. It effectively does the same as this code:(new JarFile(File, boolean, int, JarFile.runtimeVersion()).
 
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- Since:
- 1.2
- See Also:
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Field SummaryFieldsModifier and TypeFieldDescriptionstatic final intCentral directory (CEN) header internal file attributes field offset.static final intCentral directory (CEN) header external file attributes field offset.static final intCentral directory (CEN) header comment length field offset.static final intCentral directory (CEN) header uncompressed file crc-32 value field offset.static final intCentral directory (CEN) header disk number start field offset.static final intCentral directory (CEN) header extra field length field offset.static final intCentral directory (CEN) header encrypt, decrypt flags field offset.static final intCentral directory (CEN) header size in bytes (including signature).static final intCentral directory (CEN) header compression method field offset.static final intCentral directory (CEN) header uncompressed size field offset.static final intCentral directory (CEN) header filename length field offset.static final intCentral directory (CEN) header LOC header offset field offset.static final longCentral directory (CEN) header signature.static final intCentral directory (CEN) header compressed size field offset.static final intCentral directory (CEN) header modification time field offset.static final intCentral directory (CEN) header version made by field offset.static final intCentral directory (CEN) header version needed to extract field offset.static final intEnd of central directory (END) header ZIP file comment length field offset.static final intEnd of central directory (END) header size in bytes (including signature).static final intEnd of central directory (END) header offset for the first CEN header field offset.static final longEnd of central directory (END) header signature.static final intEnd of central directory (END) header central directory size in bytes field offset.static final intEnd of central directory (END) header number of entries on this disk field offset.static final intEnd of central directory (END) header total number of entries field offset.static final intExtra local (EXT) header uncompressed file crc-32 value field offset.static final intExtra local (EXT) header size in bytes (including signature).static final intExtra local (EXT) header uncompressed size field offset.static final longExtra local (EXT) header signature.static final intExtra local (EXT) header compressed size field offset.static final intLocal file (LOC) header uncompressed file crc-32 value field offset.static final intLocal file (LOC) header extra field length field offset.static final intLocal file (LOC) header general purpose bit flag field offset.static final intLocal file (LOC) header size in bytes (including signature).static final intLocal file (LOC) header compression method field offset.static final intLocal file (LOC) header uncompressed size field offset.static final intLocal file (LOC) header filename length field offset.static final longLocal file (LOC) header signature.static final intLocal file (LOC) header compressed size field offset.static final intLocal file (LOC) header modification time field offset.static final intLocal file (LOC) header version needed to extract field offset.static final StringThe JAR manifest file name.Fields declared in class java.util.zip.ZipFileOPEN_DELETE, OPEN_READ
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Constructor SummaryConstructorsConstructorDescriptionCreates a newJarFileto read from the specifiedFileobject.Creates a newJarFileto read from the specifiedFileobject.Creates a newJarFileto read from the specifiedFileobject in the specified mode.JarFile(File file, boolean verify, int mode, Runtime.Version version) Creates a newJarFileto read from the specifiedFileobject in the specified mode.Creates a newJarFileto read from the specified filename.Creates a newJarFileto read from the specified filename.
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Method SummaryModifier and TypeMethodDescriptionstatic Runtime.VersionReturns the version that represents the unversioned configuration of a multi-release jar file.entries()Returns an enumeration of the jar file entries.Returns theZipEntryfor the given base entry name ornullif not found.Returns an input stream for reading the contents of the specified ZIP file entry.getJarEntry(String name) Returns theJarEntryfor the given base entry name ornullif not found.Returns the jar file manifest, ornullif none.final Runtime.VersionReturns the maximum version used when searching for versioned entries.final booleanIndicates whether or not this jar file is a multi-release jar file.static Runtime.VersionReturns the version that represents the effective runtime versioned configuration of a multi-release jar file.stream()Returns an orderedStreamover the jar file entries.Returns aStreamof the versioned jar file entries.
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Field Details- 
MANIFEST_NAME
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LOCSIGstatic final long LOCSIGLocal file (LOC) header signature.- See Also:
 
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EXTSIGstatic final long EXTSIGExtra local (EXT) header signature.- See Also:
 
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CENSIGstatic final long CENSIGCentral directory (CEN) header signature.- See Also:
 
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ENDSIGstatic final long ENDSIGEnd of central directory (END) header signature.- See Also:
 
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LOCHDRstatic final int LOCHDRLocal file (LOC) header size in bytes (including signature).- See Also:
 
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EXTHDRstatic final int EXTHDRExtra local (EXT) header size in bytes (including signature).- See Also:
 
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CENHDRstatic final int CENHDRCentral directory (CEN) header size in bytes (including signature).- See Also:
 
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ENDHDRstatic final int ENDHDREnd of central directory (END) header size in bytes (including signature).- See Also:
 
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LOCVERstatic final int LOCVERLocal file (LOC) header version needed to extract field offset.- See Also:
 
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LOCFLGstatic final int LOCFLGLocal file (LOC) header general purpose bit flag field offset.- See Also:
 
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LOCHOWstatic final int LOCHOWLocal file (LOC) header compression method field offset.- See Also:
 
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LOCTIMstatic final int LOCTIMLocal file (LOC) header modification time field offset.- See Also:
 
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LOCCRCstatic final int LOCCRCLocal file (LOC) header uncompressed file crc-32 value field offset.- See Also:
 
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LOCSIZstatic final int LOCSIZLocal file (LOC) header compressed size field offset.- See Also:
 
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LOCLENstatic final int LOCLENLocal file (LOC) header uncompressed size field offset.- See Also:
 
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LOCNAMstatic final int LOCNAMLocal file (LOC) header filename length field offset.- See Also:
 
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LOCEXTstatic final int LOCEXTLocal file (LOC) header extra field length field offset.- See Also:
 
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EXTCRCstatic final int EXTCRCExtra local (EXT) header uncompressed file crc-32 value field offset.- See Also:
 
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EXTSIZstatic final int EXTSIZExtra local (EXT) header compressed size field offset.- See Also:
 
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EXTLENstatic final int EXTLENExtra local (EXT) header uncompressed size field offset.- See Also:
 
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CENVEMstatic final int CENVEMCentral directory (CEN) header version made by field offset.- See Also:
 
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CENVERstatic final int CENVERCentral directory (CEN) header version needed to extract field offset.- See Also:
 
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CENFLGstatic final int CENFLGCentral directory (CEN) header encrypt, decrypt flags field offset.- See Also:
 
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CENHOWstatic final int CENHOWCentral directory (CEN) header compression method field offset.- See Also:
 
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CENTIMstatic final int CENTIMCentral directory (CEN) header modification time field offset.- See Also:
 
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CENCRCstatic final int CENCRCCentral directory (CEN) header uncompressed file crc-32 value field offset.- See Also:
 
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CENSIZstatic final int CENSIZCentral directory (CEN) header compressed size field offset.- See Also:
 
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CENLENstatic final int CENLENCentral directory (CEN) header uncompressed size field offset.- See Also:
 
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CENNAMstatic final int CENNAMCentral directory (CEN) header filename length field offset.- See Also:
 
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CENEXTstatic final int CENEXTCentral directory (CEN) header extra field length field offset.- See Also:
 
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CENCOMstatic final int CENCOMCentral directory (CEN) header comment length field offset.- See Also:
 
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CENDSKstatic final int CENDSKCentral directory (CEN) header disk number start field offset.- See Also:
 
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CENATTstatic final int CENATTCentral directory (CEN) header internal file attributes field offset.- See Also:
 
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CENATXstatic final int CENATXCentral directory (CEN) header external file attributes field offset.- See Also:
 
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CENOFFstatic final int CENOFFCentral directory (CEN) header LOC header offset field offset.- See Also:
 
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ENDSUBstatic final int ENDSUBEnd of central directory (END) header number of entries on this disk field offset.- See Also:
 
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ENDTOTstatic final int ENDTOTEnd of central directory (END) header total number of entries field offset.- See Also:
 
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ENDSIZstatic final int ENDSIZEnd of central directory (END) header central directory size in bytes field offset.- See Also:
 
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ENDOFFstatic final int ENDOFFEnd of central directory (END) header offset for the first CEN header field offset.- See Also:
 
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ENDCOMstatic final int ENDCOMEnd of central directory (END) header ZIP file comment length field offset.- See Also:
 
 
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Constructor Details- 
JarFileCreates a newJarFileto read from the specified filename. TheJarFilewill 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
 
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JarFileCreates a newJarFileto read from the specified filename.- 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
 
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JarFileCreates a newJarFileto read from the specifiedFileobject. TheJarFilewill 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
 
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JarFileCreates a newJarFileto read from the specifiedFileobject.- 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
 
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JarFileCreates a newJarFileto read from the specifiedFileobject in the specified mode. The mode argument must be eitherOPEN_READorOPEN_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- modeargument is invalid
- Since:
- 1.3
 
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JarFileCreates a newJarFileto read from the specifiedFileobject in the specified mode. The mode argument must be eitherOPEN_READorOPEN_READ | OPEN_DELETE. The version argument, after being converted to a canonical form, is used to configure theJarFilefor processing multi-release jar files.The canonical form derived from the version parameter is Runtime.Version.parse(Integer.toString(n))wherenisMath.max(version.feature(), JarFile.baseVersion().feature()).- 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
- version- specifies the release version for a multi-release jar file
- Throws:
- IOException- if an I/O error has occurred
- IllegalArgumentException- if the- modeargument is invalid
- NullPointerException- if- versionis- null
- Since:
- 9
 
 
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Method Details- 
baseVersionReturns the version that represents the unversioned configuration of a multi-release jar file.- Returns:
- the version that represents the unversioned configuration
- Since:
- 9
 
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runtimeVersionReturns the version that represents the effective runtime versioned configuration of a multi-release jar file.By default the feature version number of the returned Versionwill be equal to the feature version number ofRuntime.version(). However, if thejdk.util.jar.versionproperty is set, the returnedVersionis derived from that property and feature version numbers may not be equal.- Returns:
- the version that represents the runtime versioned configuration
- Since:
- 9
 
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getVersionReturns the maximum version used when searching for versioned entries.If this JarFileis 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
 
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isMultiReleasepublic 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
 
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getManifestReturns the jar file manifest, ornullif none.- Returns:
- the jar file manifest, or nullif none
- Throws:
- IllegalStateException- may be thrown if the jar file has been closed
- IOException- if an I/O error has occurred
 
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getJarEntryReturns theJarEntryfor the given base entry name ornullif not found.If this JarFileis a multi-release jar file and is configured to be processed as such, then a search is performed to find and return aJarEntrythat is the latest versioned entry associated with the given entry name. The returnedJarEntryis the versioned entry corresponding to the given base entry name prefixed with the string"META-INF/versions/{n}/", for the largest value ofnfor which an entry exists. If such a versioned entry does not exist, then theJarEntryfor the base entry is returned, otherwisenullis returned if no entries are found. The initial value for the versionnis the maximum version as returned by the methodgetVersion().- Implementation Requirements:
- This implementation invokesgetEntry(String).
- Parameters:
- name- the jar file entry name
- Returns:
- the JarEntryfor the given entry name, or the versioned entry name, ornullif not found
- Throws:
- IllegalStateException- may be thrown if the jar file has been closed
- See Also:
 
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getEntryReturns theZipEntryfor the given base entry name ornullif not found.If this JarFileis a multi-release jar file and is configured to be processed as such, then a search is performed to find and return aZipEntrythat is the latest versioned entry associated with the given entry name. The returnedZipEntryis the versioned entry corresponding to the given base entry name prefixed with the string"META-INF/versions/{n}/", for the largest value ofnfor which an entry exists. If such a versioned entry does not exist, then theZipEntryfor the base entry is returned, otherwisenullis returned if no entries are found. The initial value for the versionnis the maximum version as returned by the methodgetVersion().- Overrides:
- getEntryin class- ZipFile
- 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 invokessuper.getEntry(name)to obtain all versioned entries.
- Parameters:
- name- the jar file entry name
- Returns:
- the ZipEntryfor the given entry name or the versioned entry name ornullif not found
- Throws:
- IllegalStateException- may be thrown if the jar file has been closed
- See Also:
 
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entriesReturns an enumeration of the jar file entries.- Overrides:
- entriesin class- ZipFile
- Returns:
- an enumeration of the jar file entries
- Throws:
- IllegalStateException- may be thrown if the jar file has been closed
 
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streamReturns an orderedStreamover the jar file entries. Entries appear in theStreamin the order they appear in the central directory of the jar file.- Overrides:
- streamin class- ZipFile
- Returns:
- an ordered Streamof entries in this jar file
- Throws:
- IllegalStateException- if the jar file has been closed
- Since:
- 1.8
 
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versionedStreamReturns aStreamof the versioned jar file entries.If this JarFileis 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 theJarFileis not configured for processing a multi-release jar file, this method returns the same stream thatstream()returns.- Returns:
- stream of versioned entries
- Since:
- 10
 
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getInputStreamReturns an input stream for reading the contents of the specified ZIP file entry.- Overrides:
- getInputStreamin class- ZipFile
- API Note:
- The InputStreamreturned by this method can wrap anInflaterInputStream, whoseread(byte[], int, int)method can modify any element of the output buffer.
- Parameters:
- ze- the ZIP file entry
- Returns:
- an input stream for reading the contents of the specified ZIP file entry or null if the ZIP file entry does not exist within the jar file
- 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
 
 
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