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/OpenJDK 21

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
See Also:

Constructor Summary

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:

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:

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:

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:

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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.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/jar/Manifest.html