JarInputStream
public
class
JarInputStream
extends ZipInputStream
| java.lang.Object | |||||
| ↳ | java.io.InputStream | ||||
| ↳ | java.io.FilterInputStream | ||||
| ↳ | java.util.zip.InflaterInputStream | ||||
| ↳ | java.util.zip.ZipInputStream | ||||
| ↳ | java.util.jar.JarInputStream | ||||
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.
See also:
Summary
Constants | |
|---|---|
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 |
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
|
Inherited constants |
|---|
Inherited fields |
|---|
Public constructors | |
|---|---|
JarInputStream(InputStream in)
Creates a new |
|
JarInputStream(InputStream in, boolean verify)
Creates a new |
|
Public methods | |
|---|---|
Manifest
|
getManifest()
Returns the |
ZipEntry
|
getNextEntry()
Reads the next ZIP file entry and positions the stream at the beginning of the entry data. |
JarEntry
|
getNextJarEntry()
Reads the next JAR file entry and positions the stream at the beginning of the entry data. |
int
|
read(byte[] b, int off, int len)
Reads from the current JAR file entry into an array of bytes. |
Protected methods | |
|---|---|
ZipEntry
|
createZipEntry(String name)
Creates a new |
Inherited methods | |
|---|---|
Constants
CENATT
public static final int CENATT
Constant Value: 36 (0x00000024)
CENATX
public static final int CENATX
Constant Value: 38 (0x00000026)
CENCOM
public static final int CENCOM
Constant Value: 32 (0x00000020)
CENCRC
public static final int CENCRC
Constant Value: 16 (0x00000010)
CENDSK
public static final int CENDSK
Constant Value: 34 (0x00000022)
CENEXT
public static final int CENEXT
Constant Value: 30 (0x0000001e)
CENFLG
public static final int CENFLG
Constant Value: 8 (0x00000008)
CENHDR
public static final int CENHDR
Constant Value: 46 (0x0000002e)
CENHOW
public static final int CENHOW
Constant Value: 10 (0x0000000a)
CENLEN
public static final int CENLEN
Constant Value: 24 (0x00000018)
CENNAM
public static final int CENNAM
Constant Value: 28 (0x0000001c)
CENOFF
public static final int CENOFF
Constant Value: 42 (0x0000002a)
CENSIG
public static final long CENSIG
Constant Value: 33639248 (0x0000000002014b50)
CENSIZ
public static final int CENSIZ
Constant Value: 20 (0x00000014)
CENTIM
public static final int CENTIM
Constant Value: 12 (0x0000000c)
CENVEM
public static final int CENVEM
Constant Value: 4 (0x00000004)
CENVER
public static final int CENVER
Constant Value: 6 (0x00000006)
ENDCOM
public static final int ENDCOM
Constant Value: 20 (0x00000014)
ENDHDR
public static final int ENDHDR
Constant Value: 22 (0x00000016)
ENDOFF
public static final int ENDOFF
Constant Value: 16 (0x00000010)
ENDSIG
public static final long ENDSIG
Constant Value: 101010256 (0x0000000006054b50)
ENDSIZ
public static final int ENDSIZ
Constant Value: 12 (0x0000000c)
ENDSUB
public static final int ENDSUB
Constant Value: 8 (0x00000008)
ENDTOT
public static final int ENDTOT
Constant Value: 10 (0x0000000a)
EXTCRC
public static final int EXTCRC
Constant Value: 4 (0x00000004)
EXTHDR
public static final int EXTHDR
Constant Value: 16 (0x00000010)
EXTLEN
public static final int EXTLEN
Constant Value: 12 (0x0000000c)
EXTSIG
public static final long EXTSIG
Constant Value: 134695760 (0x0000000008074b50)
EXTSIZ
public static final int EXTSIZ
Constant Value: 8 (0x00000008)
LOCCRC
public static final int LOCCRC
Constant Value: 14 (0x0000000e)
LOCEXT
public static final int LOCEXT
Constant Value: 28 (0x0000001c)
LOCFLG
public static final int LOCFLG
Constant Value: 6 (0x00000006)
LOCHDR
public static final int LOCHDR
Constant Value: 30 (0x0000001e)
LOCHOW
public static final int LOCHOW
Constant Value: 8 (0x00000008)
LOCLEN
public static final int LOCLEN
Constant Value: 22 (0x00000016)
LOCNAM
public static final int LOCNAM
Constant Value: 26 (0x0000001a)
LOCSIG
public static final long LOCSIG
Constant Value: 67324752 (0x0000000004034b50)
LOCSIZ
public static final int LOCSIZ
Constant Value: 18 (0x00000012)
LOCTIM
public static final int LOCTIM
Constant Value: 10 (0x0000000a)
LOCVER
public static final int LOCVER
Constant Value: 4 (0x00000004)
Public constructors
JarInputStream
public JarInputStream (InputStream in)
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 |
InputStream: the actual input stream |
| Throws | |
|---|---|
IOException |
if an I/O error has occurred |
JarInputStream
public JarInputStream (InputStream in, boolean verify)
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 |
InputStream: the actual input stream |
verify |
boolean: whether or not to verify the JarInputStream if
it is signed. |
| Throws | |
|---|---|
IOException |
if an I/O error has occurred |
Public methods
getManifest
public Manifest getManifest ()
Returns the Manifest for this JAR file, or
null if none.
| Returns | |
|---|---|
Manifest |
the Manifest for this JAR file, or
null if none. |
getNextEntry
public ZipEntry getNextEntry ()
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.
| Returns | |
|---|---|
ZipEntry |
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 ()
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 | |
|---|---|
JarEntry |
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)
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.
| Parameters | |
|---|---|
b |
byte: the buffer into which the data is read |
off |
int: the start offset in the destination array b |
len |
int: the maximum number of bytes to read |
| Returns | |
|---|---|
int |
the actual number of bytes read, or -1 if the end of the entry is reached |
| Throws | |
|---|---|
NullPointerException |
If b is null. |
IndexOutOfBoundsException |
If off is negative,
len is negative, or len is greater than
b.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. |
Protected methods
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.
| Parameters | |
|---|---|
name |
String: the name of the JAR/ZIP file entry |
| Returns | |
|---|---|
ZipEntry |
the JarEntry object just created |