java.util.jar
class JarFile

java.lang.Object java.util.zip.ZipFile java.util.jar.JarFile

All Implemented Interfaces:

ZipConstants

Most common way to construct:

File file = …;

JarFile jarFile = new JarFile(file);

Based on 60 examples

public class JarFile
extends ZipFile

The JarFile class is used to read the contents of a jar file from any file that can be opened with java.io.RandomAccessFile. It extends the class java.util.zip.ZipFile with support for reading an optional Manifest entry. The Manifest can be used to specify meta-information about the jar file and its entries.

Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a {@link NullPointerException} to be thrown.

MANIFEST_NAME

public static final String MANIFEST_NAME

The JAR manifest file name.

JarFile

public JarFile(File file)
        throws IOException

Creates a new JarFile to read from the specified File object. The JarFile will be verified if it is signed.

Parameters:

file - the jar file to be opened for reading

Throws:

IOException - if an I/O error has occurred

JarFile

public JarFile(File file,
               boolean verify)
        throws IOException

Creates a new JarFile to read from the specified File object.

Parameters:

file - the jar file to be opened for reading

verify - whether or not to verify the jar file if it is signed.

Throws:

IOException - if an I/O error has occurred

JarFile

public JarFile(File file,
               boolean verify,
               int mode)
        throws IOException

Creates a new JarFile to read from the specified File object in the specified mode. The mode argument must be either OPEN_READ or OPEN_READ | OPEN_DELETE.

Parameters:

file - the jar file to be opened for reading

verify - whether or not to verify the jar file if it is signed.

mode - the mode in which the file is to be opened

Throws:

IOException - if an I/O error has occurred

JarFile

public JarFile(String name)
        throws IOException

Creates a new JarFile to read from the specified file name. The JarFile will be verified if it is signed.

Parameters:

name - the name of the jar file to be opened for reading

Throws:

IOException - if an I/O error has occurred

JarFile

public JarFile(String name,
               boolean verify)
        throws IOException

Creates a new JarFile to read from the specified file name.

Parameters:

name - the name of the jar file to be opened for reading

verify - whether or not to verify the jar file if it is signed.

Throws:

IOException - if an I/O error has occurred

entries

public Enumeration entries()

Returns an enumeration of the zip file entries.

Overrides:

entries in class ZipFile

getEntry

public ZipEntry getEntry(String name)

Returns the ZipEntry for the given entry name or null if not found.

Overrides:

getEntry in class ZipFile

Parameters:

name - the jar file entry name

Returns:

the ZipEntry for the given entry name or null if not found

getInputStream

public synchronized InputStream getInputStream(ZipEntry ze)
                                        throws IOException

Returns an input stream for reading the contents of the specified zip file entry.

Overrides:

getInputStream in class ZipFile

Parameters:

ze - the zip file entry

Returns:

an input stream for reading the contents of the specified zip file entry

Throws:

IOException - if an I/O error has occurred

getJarEntry

public JarEntry getJarEntry(String name)

Returns the JarEntry for the given entry name or null if not found.

Parameters:

name - the jar file entry name

Returns:

the JarEntry for the given entry name or null if not found.

getManifest

public Manifest getManifest()
                     throws IOException

Returns the jar file manifest, or null if none.

Returns:

the jar file manifest, or null if none

Throws:

IOException