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
CENSIG
public static final long CENSIG
Constant Value: 33639248 (0x0000000002014b50)
ENDSIG
public static final long ENDSIG
Constant Value: 101010256 (0x0000000006054b50)
EXTSIG
public static final long EXTSIG
Constant Value: 134695760 (0x0000000008074b50)
LOCSIG
public static final long LOCSIG
Constant Value: 67324752 (0x0000000004034b50)
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 |

