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 object to the underlying map for equality. Returns true if the given object is also a Map and the two maps 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