JarInputStream (Java Platform SE 8 )
Keywords: java.util.jar.JarInputStream class
Date: 2026-04-17

compact1, compact2, compact3
java.util.jar

## 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`

- - ### Field Summary

    Fields
    Modifier and Type | Field and 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 inherited from class java.util.zip.InflaterInputStream

      `buf, inf, len`

    - ### Fields inherited from class java.io.FilterInputStream

      `in`

  - ### Constructor Summary

    Constructors
    Constructor and 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.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and 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 inherited from class java.util.zip.ZipInputStream

      `available, close, closeEntry, skip`

    - ### Methods inherited from class java.util.zip.InflaterInputStream

      `fill, mark, markSupported, read, reset`

    - ### Methods inherited from class java.io.FilterInputStream

      `read`

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### 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

  - ### Constructor Detail

    - #### 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

  - ### Method Detail

    - #### 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

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2026, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.