Module java.base

Package java.util.jar

Class Manifest

java.lang.Object

java.util.jar.Manifest

All Implemented Interfaces:

Cloneable

public class Manifest
extends Object
implements Cloneable

The Manifest class is used to maintain Manifest entry names and their associated Attributes. There are main Manifest Attributes as well as per-entry Attributes. For information on the Manifest format, please see the Manifest format specification.

Since:

1.2

External Specifications

• JAR File Specification

See Also:

• Attributes

Constructor Summary

Constructors

Constructor	Description
Manifest()	Constructs a new, empty Manifest.
Manifest(InputStream is)	Constructs a new Manifest from the specified input stream.
Manifest(Manifest man)	Constructs a new Manifest that is a copy of the specified Manifest.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears the main Attributes as well as the entries in this Manifest.
Object	clone()	Returns a shallow copy of this Manifest.
boolean	equals(Object o)	Returns true if the specified Object is also a Manifest and has the same main Attributes and entries.
Attributes	getAttributes(String name)	Returns the Attributes for the specified entry name.
Map<String,Attributes>	getEntries()	Returns a Map of the entries contained in this Manifest.
Attributes	getMainAttributes()	Returns the main Attributes for the Manifest.
int	hashCode()	Returns the hash code for this Manifest.
void	read(InputStream is)	Reads the Manifest from the specified InputStream.
void	write(OutputStream out)	Writes the Manifest to the specified OutputStream.

Methods declared in class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Manifest

public Manifest()

Constructs a new, empty Manifest.

Manifest

public Manifest(InputStream is)
         throws IOException

Constructs a new Manifest from the specified input stream.

Parameters:

is - the input stream containing manifest data

Throws:

IOException - if an I/O error has occurred

Manifest

public Manifest(Manifest man)

Constructs a new Manifest that is a copy of the specified Manifest.

Parameters:

man - the Manifest to copy

Method Details

getMainAttributes

public Attributes getMainAttributes()

Returns the main Attributes for the Manifest.

Returns:

the main Attributes for the Manifest

getEntries

public Map<String,Attributes> getEntries()

Returns a Map of the entries contained in this Manifest. Each entry is represented by a String name (key) and associated Attributes (value). The Map permits the null key, but no entry with a null key is created by read(java.io.InputStream), nor is such an entry written by using write(java.io.OutputStream).

Returns:

a Map of the entries contained in this Manifest

getAttributes

public Attributes getAttributes(String name)

Returns the Attributes for the specified entry name. This method is defined as:

      return (Attributes)getEntries().get(name)
 

Though null is a valid name, when getAttributes(null) is invoked on a Manifest obtained from a jar file, null will be returned. While jar files themselves do not allow null-named attributes, it is possible to invoke getEntries() on a Manifest, and on that result, invoke put with a null key and an arbitrary value. Subsequent invocations of getAttributes(null) will return the just-put value.

Note that this method does not return the manifest's main attributes; see getMainAttributes().

Parameters:

name - entry name

Returns:

the Attributes for the specified entry name

clear

public void clear()

Clears the main Attributes as well as the entries in this Manifest.

write

public void write(OutputStream out)
           throws IOException

Writes the Manifest to the specified OutputStream. Attributes.Name.MANIFEST_VERSION must be set in MainAttributes prior to invoking this method.

Parameters:

out - the output stream

Throws:

IOException - if an I/O error has occurred

See Also:

• getMainAttributes()

read

public void read(InputStream is)
          throws IOException

Reads the Manifest from the specified InputStream. The entry names and attributes read will be merged in with the current manifest entries.

Parameters:

is - the input stream

Throws:

IOException - if an I/O error has occurred

equals

public boolean equals(Object o)

Returns true if the specified Object is also a Manifest and has the same main Attributes and entries.

Overrides:

equals in class Object

Parameters:

o - the object to be compared

Returns:

true if the specified Object is also a Manifest and has the same main Attributes and entries

See Also:

• Object.hashCode()
• HashMap

hashCode

public int hashCode()

Returns the hash code for this Manifest.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object

See Also:

• Object.equals(java.lang.Object)
• System.identityHashCode(java.lang.Object)

clone

public Object clone()

Returns a shallow copy of this Manifest. The shallow copy is implemented as follows:

     public Object clone() { return new Manifest(this); }
 

Overrides:

clone in class Object

Returns:

a shallow copy of this Manifest

See Also:

• Cloneable