JarInputStream
Class JarInputStream
- java.lang.Object
-
- java.io.InputStream
-
- java.io.FilterInputStream
-
- java.util.zip.InflaterInputStream
-
- java.util.zip.ZipInputStream
-
- java.util.jar.JarInputStream
- All Implemented Interfaces:
- Closeable, AutoCloseable
public class JarInputStream extends ZipInputStream
The JarInputStream
class is used to read the contents of a JAR file from any input stream. It extends the class java.util.zip.ZipInputStream
with support for reading an optional Manifest
entry. The Manifest
can be used to store meta-information about the JAR file and its entries.
- Since:
- 1.2
- See Also:
-
Manifest
,ZipInputStream
Fields
LOCSIG
public static final long LOCSIG
EXTSIG
public static final long EXTSIG
CENSIG
public static final long CENSIG
ENDSIG
public static final long ENDSIG
LOCHDR
public static final int LOCHDR
EXTHDR
public static final int EXTHDR
CENHDR
public static final int CENHDR
ENDHDR
public static final int ENDHDR
LOCVER
public static final int LOCVER
LOCFLG
public static final int LOCFLG
LOCHOW
public static final int LOCHOW
LOCTIM
public static final int LOCTIM
LOCCRC
public static final int LOCCRC
LOCSIZ
public static final int LOCSIZ
LOCLEN
public static final int LOCLEN
LOCNAM
public static final int LOCNAM
LOCEXT
public static final int LOCEXT
EXTCRC
public static final int EXTCRC
EXTSIZ
public static final int EXTSIZ
EXTLEN
public static final int EXTLEN
CENVEM
public static final int CENVEM
CENVER
public static final int CENVER
CENFLG
public static final int CENFLG
CENHOW
public static final int CENHOW
CENTIM
public static final int CENTIM
CENCRC
public static final int CENCRC
CENSIZ
public static final int CENSIZ
CENLEN
public static final int CENLEN
CENNAM
public static final int CENNAM
CENEXT
public static final int CENEXT
CENCOM
public static final int CENCOM
CENDSK
public static final int CENDSK
CENATT
public static final int CENATT
CENATX
public static final int CENATX
CENOFF
public static final int CENOFF
ENDSUB
public static final int ENDSUB
ENDTOT
public static final int ENDTOT
ENDSIZ
public static final int ENDSIZ
ENDOFF
public static final int ENDOFF
ENDCOM
public static final int ENDCOM
Constructors
JarInputStream
public JarInputStream(InputStream in) throws IOException
Creates a new JarInputStream
and reads the optional manifest. If a manifest is present, also attempts to verify the signatures if the JarInputStream is signed.
- Parameters:
-
in
- the actual input stream - Throws:
-
IOException
- if an I/O error has occurred
JarInputStream
public JarInputStream(InputStream in, boolean verify) throws IOException
Creates a new JarInputStream
and reads the optional manifest. If a manifest is present and verify is true, also attempts to verify the signatures if the JarInputStream is signed.
- Parameters:
-
in
- the actual input stream -
verify
- whether or not to verify the JarInputStream if it is signed. - Throws:
-
IOException
- if an I/O error has occurred
Methods
getManifest
public Manifest getManifest()
Returns the Manifest
for this JAR file, or null
if none.
- Returns:
- the
Manifest
for this JAR file, ornull
if none.
getNextEntry
public ZipEntry getNextEntry() throws IOException
Reads the next ZIP file entry and positions the stream at the beginning of the entry data. If verification has been enabled, any invalid signature detected while positioning the stream for the next entry will result in an exception.
- Overrides:
-
getNextEntry
in classZipInputStream
- Returns:
- the next ZIP file entry, or null if there are no more entries
- Throws:
-
ZipException
- if a ZIP file error has occurred -
IOException
- if an I/O error has occurred -
SecurityException
- if any of the jar file entries are incorrectly signed.
getNextJarEntry
public JarEntry getNextJarEntry() throws IOException
Reads the next JAR file entry and positions the stream at the beginning of the entry data. If verification has been enabled, any invalid signature detected while positioning the stream for the next entry will result in an exception.
- Returns:
- the next JAR file entry, or null if there are no more entries
- Throws:
-
ZipException
- if a ZIP file error has occurred -
IOException
- if an I/O error has occurred -
SecurityException
- if any of the jar file entries are incorrectly signed.
read
public int read(byte[] b, int off, int len) throws IOException
Reads from the current JAR file entry into an array of bytes. If len
is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0
is returned. If verification has been enabled, any invalid signature on the current entry will be reported at some point before the end of the entry is reached.
- Overrides:
-
read
in classZipInputStream
- Parameters:
-
b
- the buffer into which the data is read -
off
- the start offset in the destination arrayb
-
len
- the maximum number of bytes to read - Returns:
- the actual number of bytes read, or -1 if the end of the entry is reached
- Throws:
-
NullPointerException
- Ifb
isnull
. -
IndexOutOfBoundsException
- Ifoff
is negative,len
is negative, orlen
is greater thanb.length - off
-
ZipException
- if a ZIP file error has occurred -
IOException
- if an I/O error has occurred -
SecurityException
- if any of the jar file entries are incorrectly signed. - See Also:
FilterInputStream.in
createZipEntry
protected ZipEntry createZipEntry(String name)
Creates a new JarEntry
(ZipEntry
) for the specified JAR file entry name. The manifest attributes of the specified JAR file entry name will be copied to the new JarEntry
.
- Overrides:
-
createZipEntry
in classZipInputStream
- Parameters:
-
name
- the name of the JAR/ZIP file entry - Returns:
- the
JarEntry
object just created
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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