Module java.base
Package java.util.jar

Class Attributes

  • All Implemented Interfaces:
    Cloneable, Map<Object,​Object>
    public class Attributes
extends Object
implements Map<Object,​Object>, Cloneable
    The Attributes class maps Manifest attribute names to associated string values. Valid attribute names are case-insensitive, are restricted to the ASCII characters in the set [0-9a-zA-Z_-], and cannot exceed 70 characters in length. There must be a colon and a SPACE after the name; the combined length will not exceed 72 characters. Attribute values can contain any characters and will be UTF8-encoded when written to the output stream. See the JAR File Specification for more information about valid attribute names and values.

    This map and its views have a predictable iteration order, namely the order that keys were inserted into the map, as with LinkedHashMap.

    Since:
    1.2
    See Also:
    Manifest

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  Attributes.Name
      The Attributes.Name class represents an attribute name stored in this Map.

      • Nested classes/interfaces declared in interface java.util.Map

        Map.Entry<K,​V>

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected Map<Object,​Object> map
      The attribute name-value mappings.

    • Constructor Summary

      Constructors 
      Constructor Description
      Attributes()
      Constructs a new, empty Attributes object with default size.
      Attributes​(int size)
      Constructs a new, empty Attributes object with the specified initial size.
      Attributes​(Attributes attr)
      Constructs a new Attributes object with the same attribute name-value mappings as in the specified Attributes.

    • Field Detail

      • map

        protected Map<Object,​Object> map
        The attribute name-value mappings.

    • Constructor Detail

      • Attributes

        public Attributes()
        Constructs a new, empty Attributes object with default size.

      • Attributes

        public Attributes​(int size)
        Constructs a new, empty Attributes object with the specified initial size.
        Parameters:
        size - the initial number of attributes

      • Attributes

        public Attributes​(Attributes attr)
        Constructs a new Attributes object with the same attribute name-value mappings as in the specified Attributes.
        Parameters:
        attr - the specified Attributes

    • Method Detail

      • get

        public Object get​(Object name)
        Returns the value of the specified attribute name, or null if the attribute name was not found.
        Specified by:
        get in interface Map<Object,​Object>
        Parameters:
        name - the attribute name
        Returns:
        the value of the specified attribute name, or null if not found.

      • getValue

        public String getValue​(String name)
        Returns the value of the specified attribute name, specified as a string, or null if the attribute was not found. The attribute name is case-insensitive.

        This method is defined as: 

              return (String)get(new Attributes.Name((String)name));
        Parameters:
        name - the attribute name as a string
        Returns:
        the String value of the specified attribute name, or null if not found.
        Throws:
        IllegalArgumentException - if the attribute name is invalid

      • getValue

        public String getValue​(Attributes.Name name)
        Returns the value of the specified Attributes.Name, or null if the attribute was not found.

        This method is defined as: 

             return (String)get(name);
        Parameters:
        name - the Attributes.Name object
        Returns:
        the String value of the specified Attribute.Name, or null if not found.

      • put

        public Object put​(Object name,
                  Object value)
        Associates the specified value with the specified attribute name (key) in this Map. If the Map previously contained a mapping for the attribute name, the old value is replaced.
        Specified by:
        put in interface Map<Object,​Object>
        Parameters:
        name - the attribute name
        value - the attribute value
        Returns:
        the previous value of the attribute, or null if none
        Throws:
        ClassCastException - if the name is not a Attributes.Name or the value is not a String

      • putValue

        public String putValue​(String name,
                       String value)
        Associates the specified value with the specified attribute name, specified as a String. The attributes name is case-insensitive. If the Map previously contained a mapping for the attribute name, the old value is replaced.

        This method is defined as: 

              return (String)put(new Attributes.Name(name), value);
        Parameters:
        name - the attribute name as a string
        value - the attribute value
        Returns:
        the previous value of the attribute, or null if none
        Throws:
        IllegalArgumentException - if the attribute name is invalid

      • remove

        public Object remove​(Object name)
        Removes the attribute with the specified name (key) from this Map. Returns the previous attribute value, or null if none.
        Specified by:
        remove in interface Map<Object,​Object>
        Parameters:
        name - attribute name
        Returns:
        the previous value of the attribute, or null if none

      • containsValue

        public boolean containsValue​(Object value)
        Returns true if this Map maps one or more attribute names (keys) to the specified value.
        Specified by:
        containsValue in interface Map<Object,​Object>
        Parameters:
        value - the attribute value
        Returns:
        true if this Map maps one or more attribute names to the specified value

      • containsKey

        public boolean containsKey​(Object name)
        Returns true if this Map contains the specified attribute name (key).
        Specified by:
        containsKey in interface Map<Object,​Object>
        Parameters:
        name - the attribute name
        Returns:
        true if this Map contains the specified attribute name

      • putAll

        public void putAll​(Map<?,​?> attr)
        Copies all of the attribute name-value mappings from the specified Attributes to this Map. Duplicate mappings will be replaced.
        Specified by:
        putAll in interface Map<Object,​Object>
        Parameters:
        attr - the Attributes to be stored in this map
        Throws:
        ClassCastException - if attr is not an Attributes

      • clear

        public void clear()
        Removes all attributes from this Map.
        Specified by:
        clear in interface Map<Object,​Object>

      • size

        public int size()
        Returns the number of attributes in this Map.
        Specified by:
        size in interface Map<Object,​Object>
        Returns:
        the number of key-value mappings in this map

      • isEmpty

        public boolean isEmpty()
        Returns true if this Map contains no attributes.
        Specified by:
        isEmpty in interface Map<Object,​Object>
        Returns:
        true if this map contains no key-value mappings

      • keySet

        public Set<Object> keySet()
        Returns a Set view of the attribute names (keys) contained in this Map.
        Specified by:
        keySet in interface Map<Object,​Object>
        Returns:
        a set view of the keys contained in this map

      • values

        public Collection<Object> values()
        Returns a Collection view of the attribute values contained in this Map.
        Specified by:
        values in interface Map<Object,​Object>
        Returns:
        a collection view of the values contained in this map

      • entrySet

        public Set<Map.Entry<Object,​Object>> entrySet()
        Returns a Collection view of the attribute name-value mappings contained in this Map.
        Specified by:
        entrySet in interface Map<Object,​Object>
        Returns:
        a set view of the mappings contained in this map

      • equals

        public boolean equals​(Object o)
        Compares the specified Attributes object with this Map for equality. Returns true if the given object is also an instance of Attributes and the two Attributes objects represent the same mappings.
        Specified by:
        equals in interface Map<Object,​Object>
        Overrides:
        equals in class Object
        Parameters:
        o - the Object to be compared
        Returns:
        true if the specified Object is equal to this Map
        See Also:
        Object.hashCode(), HashMap

      • clone

        public Object clone()
        Returns a copy of the Attributes, implemented as follows: 
             public Object clone() { return new Attributes(this); }
        Since the attribute names and values are themselves immutable, the Attributes returned can be safely modified without affecting the original.
        Overrides:
        clone in class Object
        Returns:
        a clone of this instance.
        See Also:
        Cloneable