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

Modifier and Type	Field	Description
`static int`	`CENATT`
`static int`	`CENATX`
`static int`	`CENCOM`
`static int`	`CENCRC`
`static int`	`CENDSK`
`static int`	`CENEXT`
`static int`	`CENFLG`
`static int`	`CENHDR`
`static int`	`CENHOW`
`static int`	`CENLEN`
`static int`	`CENNAM`
`static int`	`CENOFF`
`static long`	`CENSIG`
`static int`	`CENSIZ`
`static int`	`CENTIM`
`static int`	`CENVEM`
`static int`	`CENVER`
`static int`	`ENDCOM`
`static int`	`ENDHDR`
`static int`	`ENDOFF`
`static long`	`ENDSIG`
`static int`	`ENDSIZ`
`static int`	`ENDSUB`
`static int`	`ENDTOT`
`static int`	`EXTCRC`
`static int`	`EXTHDR`
`static int`	`EXTLEN`
`static long`	`EXTSIG`
`static int`	`EXTSIZ`
`static int`	`LOCCRC`
`static int`	`LOCEXT`
`static int`	`LOCFLG`
`static int`	`LOCHDR`
`static int`	`LOCHOW`
`static int`	`LOCLEN`
`static int`	`LOCNAM`
`static long`	`LOCSIG`
`static int`	`LOCSIZ`
`static int`	`LOCTIM`
`static int`	`LOCVER`

Fields declared in class java.util.zip.InflaterInputStream

buf, inf, len

Fields declared in class java.io.FilterInputStream

in

Constructors

Constructor	Description
`JarInputStream(InputStream in)`	Creates a new `JarInputStream` and reads the optional manifest.
`JarInputStream(InputStream in, boolean verify)`	Creates a new `JarInputStream` and reads the optional manifest.

Methods

Modifier and Type	Method	Description
`protected ZipEntry`	`createZipEntry(String name)`	Creates a new `JarEntry` (`ZipEntry`) for the specified JAR file entry name.
`Manifest`	`getManifest()`	Returns the `Manifest` for this JAR file, or `null` if none.
`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.

Methods declared in class java.util.zip.ZipInputStream

available, close, closeEntry, skip

Methods declared in class java.util.zip.InflaterInputStream

fill, mark, markSupported, read, reset

Methods declared in class java.io.FilterInputStream

read

Methods declared in class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Fields

LOCSIG

public static final long LOCSIG

See Also:: Constant Field Values

EXTSIG

public static final long EXTSIG

See Also:: Constant Field Values

CENSIG

public static final long CENSIG

See Also:: Constant Field Values

ENDSIG

public static final long ENDSIG

See Also:: Constant Field Values

LOCHDR

public static final int LOCHDR

See Also:: Constant Field Values

EXTHDR

public static final int EXTHDR

See Also:: Constant Field Values

CENHDR

public static final int CENHDR

See Also:: Constant Field Values

ENDHDR

public static final int ENDHDR

See Also:: Constant Field Values

LOCVER

public static final int LOCVER

See Also:: Constant Field Values

LOCFLG

public static final int LOCFLG

See Also:: Constant Field Values

LOCHOW

public static final int LOCHOW

See Also:: Constant Field Values

LOCTIM

public static final int LOCTIM

See Also:: Constant Field Values

LOCCRC

public static final int LOCCRC

See Also:: Constant Field Values

LOCSIZ

public static final int LOCSIZ

See Also:: Constant Field Values

LOCLEN

public static final int LOCLEN

See Also:: Constant Field Values

LOCNAM

public static final int LOCNAM

See Also:: Constant Field Values

LOCEXT

public static final int LOCEXT

See Also:: Constant Field Values

EXTCRC

public static final int EXTCRC

See Also:: Constant Field Values

EXTSIZ

public static final int EXTSIZ

See Also:: Constant Field Values

EXTLEN

public static final int EXTLEN

See Also:: Constant Field Values

CENVEM

public static final int CENVEM

See Also:: Constant Field Values

CENVER

public static final int CENVER

See Also:: Constant Field Values

CENFLG

public static final int CENFLG

See Also:: Constant Field Values

CENHOW

public static final int CENHOW

See Also:: Constant Field Values

CENTIM

public static final int CENTIM

See Also:: Constant Field Values

CENCRC

public static final int CENCRC

See Also:: Constant Field Values

CENSIZ

public static final int CENSIZ

See Also:: Constant Field Values

CENLEN

public static final int CENLEN

See Also:: Constant Field Values

CENNAM

public static final int CENNAM

See Also:: Constant Field Values

CENEXT

public static final int CENEXT

See Also:: Constant Field Values

CENCOM

public static final int CENCOM

See Also:: Constant Field Values

CENDSK

public static final int CENDSK

See Also:: Constant Field Values

CENATT

public static final int CENATT

See Also:: Constant Field Values

CENATX

public static final int CENATX

See Also:: Constant Field Values

CENOFF

public static final int CENOFF

See Also:: Constant Field Values

ENDSUB

public static final int ENDSUB

See Also:: Constant Field Values

ENDTOT

public static final int ENDTOT

See Also:: Constant Field Values

ENDSIZ

public static final int ENDSIZ

See Also:: Constant Field Values

ENDOFF

public static final int ENDOFF

See Also:: Constant Field Values

ENDCOM

public static final int ENDCOM

See Also:: Constant Field Values

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, or null 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 class ZipInputStream
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 class ZipInputStream
Parameters:: b - the buffer into which the data is read; off - the start offset in the destination array b; 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 - 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.
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 class ZipInputStream
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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https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/jar/JarInputStream.html