Class 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. If the verify flag is on when opening a signed jar file, the content of the file is verified against its signature embedded inside the file. 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.

Fields

MANIFEST_NAME

public static final String MANIFEST_NAME

The JAR manifest file name.

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LOCSIG

public static final long LOCSIG

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EXTSIG

public static final long EXTSIG

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CENSIG

public static final long CENSIG

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ENDSIG

public static final long ENDSIG

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LOCHDR

public static final int LOCHDR

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EXTHDR

public static final int EXTHDR

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CENHDR

public static final int CENHDR

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ENDHDR

public static final int ENDHDR

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LOCVER

public static final int LOCVER

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LOCFLG

public static final int LOCFLG

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LOCHOW

public static final int LOCHOW

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LOCTIM

public static final int LOCTIM

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LOCCRC

public static final int LOCCRC

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LOCSIZ

public static final int LOCSIZ

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LOCLEN

public static final int LOCLEN

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LOCNAM

public static final int LOCNAM

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LOCEXT

public static final int LOCEXT

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EXTCRC

public static final int EXTCRC

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EXTSIZ

public static final int EXTSIZ

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EXTLEN

public static final int EXTLEN

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CENVEM

public static final int CENVEM

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CENVER

public static final int CENVER

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CENFLG

public static final int CENFLG

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CENHOW

public static final int CENHOW

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CENTIM

public static final int CENTIM

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CENCRC

public static final int CENCRC

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CENSIZ

public static final int CENSIZ

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CENLEN

public static final int CENLEN

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CENNAM

public static final int CENNAM

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CENEXT

public static final int CENEXT

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CENCOM

public static final int CENCOM

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CENDSK

public static final int CENDSK

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CENATT

public static final int CENATT

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CENATX

public static final int CENATX

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CENOFF

public static final int CENOFF

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ENDSUB

public static final int ENDSUB

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ENDTOT

public static final int ENDTOT

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ENDSIZ

public static final int ENDSIZ

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ENDOFF

public static final int ENDOFF

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ENDCOM

public static final int ENDCOM

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Constructors

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 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

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 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.

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 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

Since:

1.3

Methods

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:

IllegalStateException - may be thrown if the jar file has been closed

IOException - if an I/O error has occurred

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.

Throws:

IllegalStateException - may be thrown if the jar file has been closed

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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

Throws:

IllegalStateException - may be thrown if the jar file has been closed

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ZipEntry

entries

public Enumeration<JarEntry> entries()

Returns an enumeration of the zip file entries.

Overrides:

entries in class ZipFile

Returns:

an enumeration of the ZIP file entries

stream

public Stream<JarEntry> stream()

Description copied from class: ZipFile

Return an ordered Stream over the ZIP file entries. Entries appear in the Stream in the order they appear in the central directory of the ZIP file.

Overrides:

stream in class ZipFile

Returns:

an ordered Stream of entries in this ZIP file

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 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