Class FilterImpl

  • All Implemented Interfaces:
    org.osgi.framework.Filter
    Direct Known Subclasses:
    FilterImpl.And, FilterImpl.Item, FilterImpl.Not, FilterImpl.Or

    abstract class FilterImpl
    extends java.lang.Object
    implements org.osgi.framework.Filter
    RFC 1960-based Filter. Filter objects can be created by calling the constructor with the desired filter string. A Filter object can be called numerous times to determine if the match argument matches the filter string that was used to create the Filter object.

    The syntax of a filter string is the string representation of LDAP search filters as defined in RFC 1960: A String Representation of LDAP Search Filters (available at http://www.ietf.org/rfc/rfc1960.txt). It should be noted that RFC 2254: A String Representation of LDAP Search Filters (available at http://www.ietf.org/rfc/rfc2254.txt) supersedes RFC 1960 but only adds extensible matching and is not applicable for this API.

    The string representation of an LDAP search filter is defined by the following grammar. It uses a prefix format.

       <filter> ::= '(' <filtercomp> ')'
       <filtercomp> ::= <and> | <or> | <not> | <item>
       <and> ::= '&' <filterlist>
       <or> ::= '|' <filterlist>
       <not> ::= '!' <filter>
       <filterlist> ::= <filter> | <filter> <filterlist>
       <item> ::= <simple> | <present> | <substring>
       <simple> ::= <attr> <filtertype> <value>
       <filtertype> ::= <equal> | <approx> | <greater> | <less>
       <equal> ::= '='
       <approx> ::= '˜='
       <greater> ::= '>='
       <less> ::= '<='
       <present> ::= <attr> '=*'
       <substring> ::= <attr> '=' <initial> <any> <final>
       <initial> ::= NULL | <value>
       <any> ::= '*' <starval>
       <starval> ::= NULL | <value> '*' <starval>
       <final> ::= NULL | <value>
     
    &lt;attr&gt; is a string representing an attribute, or key, in the properties objects of the registered services. Attribute names are not case sensitive; that is cn and CN both refer to the same attribute. &lt;value&gt; is a string representing the value, or part of one, of a key in the properties objects of the registered services. If a &lt;value&gt; must contain one of the characters ' *' or '(' or ')', these characters should be escaped by preceding them with the backslash '\' character. Note that although both the &lt;substring&gt; and &lt;present&gt; productions can produce the 'attr=*' construct, this construct is used only to denote a presence filter.

    Examples of LDAP filters are:

       "(cn=Babs Jensen)"
       "(!(cn=Tim Howes))"
       "(&(" + Constants.OBJECTCLASS + "=Person)(|(sn=Jensen)(cn=Babs J*)))"
       "(o=univ*of*mich*)"
     

    The approximate match (~=) is implementation specific but should at least ignore case and white space differences. Optional are codes like soundex or other smart "closeness" comparisons.

    Comparison of values is not straightforward. Strings are compared differently than numbers and it is possible for a key to have multiple values. Note that that keys in the match argument must always be strings. The comparison is defined by the object type of the key's value. The following rules apply for comparison:

    Property Value Type Comparison Type
    String String comparison
    Integer, Long, Float, Double, Byte, Short, BigInteger, BigDecimal numerical comparison
    Character character comparison
    Boolean equality comparisons only
    [] (array) recursively applied to values
    Collection recursively applied to values
    Note: arrays of primitives are also supported.
    A filter matches a key that has multiple values if it matches at least one of those values. For example,
     Dictionary d = new Hashtable();
     d.put("cn", new String[] {
            "a", "b", "c"
     });
     
    d will match (cn=a) and also (cn=b)

    A filter component that references a key having an unrecognizable data type will evaluate to false .

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.lang.String filterString  
    • Constructor Summary

      Constructors 
      Constructor Description
      FilterImpl()  
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      (package private) static FilterImpl createFilter​(java.lang.String filterString)
      Creates a FilterImpl object.
      boolean equals​(java.lang.Object obj)
      Compares this Filter to another Filter.
      int hashCode()
      Returns the hashCode for this Filter.
      boolean match​(java.util.Dictionary<java.lang.String,​?> dictionary)
      Filter using a Dictionary with case insensitive key lookup.
      boolean match​(org.osgi.framework.ServiceReference<?> reference)
      Filter using a service's properties.
      boolean matchCase​(java.util.Dictionary<java.lang.String,​?> dictionary)
      Filter using a Dictionary.
      boolean matches​(java.util.Map<java.lang.String,​?> map)
      Filter using a Map.
      (package private) abstract boolean matches0​(java.util.Map<java.lang.String,​?> map)  
      (package private) abstract java.lang.StringBuilder normalize​(java.lang.StringBuilder sb)
      Returns this Filter's normalized filter string.
      java.lang.String toString()
      Returns this Filter's filter string.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
    • Field Detail

      • filterString

        private transient java.lang.String filterString
    • Constructor Detail

      • FilterImpl

        FilterImpl()
    • Method Detail

      • createFilter

        static FilterImpl createFilter​(java.lang.String filterString)
                                throws org.osgi.framework.InvalidSyntaxException
        Creates a FilterImpl object. This filter object may be used to match a ServiceReference or a Dictionary.

        If the filter cannot be parsed, an InvalidSyntaxException will be thrown with a human readable message where the filter became unparsable.

        Parameters:
        filterString - the filter string.
        Throws:
        org.osgi.framework.InvalidSyntaxException - If the filter parameter contains an invalid filter string that cannot be parsed.
      • match

        public boolean match​(org.osgi.framework.ServiceReference<?> reference)
        Filter using a service's properties.

        This Filter is executed using the keys and values of the referenced service's properties. The keys are looked up in a case insensitive manner.

        Specified by:
        match in interface org.osgi.framework.Filter
        Parameters:
        reference - The reference to the service whose properties are used in the match.
        Returns:
        true if the service's properties match this Filter; false otherwise.
      • match

        public boolean match​(java.util.Dictionary<java.lang.String,​?> dictionary)
        Filter using a Dictionary with case insensitive key lookup. This Filter is executed using the specified Dictionary's keys and values. The keys are looked up in a case insensitive manner.
        Specified by:
        match in interface org.osgi.framework.Filter
        Parameters:
        dictionary - The Dictionary whose key/value pairs are used in the match.
        Returns:
        true if the Dictionary's values match this filter; false otherwise.
        Throws:
        java.lang.IllegalArgumentException - If dictionary contains case variants of the same key name.
      • matchCase

        public boolean matchCase​(java.util.Dictionary<java.lang.String,​?> dictionary)
        Filter using a Dictionary. This Filter is executed using the specified Dictionary's keys and values. The keys are looked up in a normal manner respecting case.
        Specified by:
        matchCase in interface org.osgi.framework.Filter
        Parameters:
        dictionary - The Dictionary whose key/value pairs are used in the match.
        Returns:
        true if the Dictionary's values match this filter; false otherwise.
        Since:
        1.3
      • matches

        public boolean matches​(java.util.Map<java.lang.String,​?> map)
        Filter using a Map. This Filter is executed using the specified Map's keys and values. The keys are looked up in a normal manner respecting case.
        Specified by:
        matches in interface org.osgi.framework.Filter
        Parameters:
        map - The Map whose key/value pairs are used in the match. Maps with null key or values are not supported. A null value is considered not present to the filter.
        Returns:
        true if the Map's values match this filter; false otherwise.
        Since:
        1.6
      • matches0

        abstract boolean matches0​(java.util.Map<java.lang.String,​?> map)
      • toString

        public java.lang.String toString()
        Returns this Filter's filter string.

        The filter string is normalized by removing whitespace which does not affect the meaning of the filter.

        Specified by:
        toString in interface org.osgi.framework.Filter
        Overrides:
        toString in class java.lang.Object
        Returns:
        This Filter's filter string.
      • normalize

        abstract java.lang.StringBuilder normalize​(java.lang.StringBuilder sb)
        Returns this Filter's normalized filter string.

        The filter string is normalized by removing whitespace which does not affect the meaning of the filter.

        Returns:
        This Filter's filter string.
      • equals

        public boolean equals​(java.lang.Object obj)
        Compares this Filter to another Filter.

        This implementation returns the result of calling this.toString().equals(obj.toString().

        Specified by:
        equals in interface org.osgi.framework.Filter
        Overrides:
        equals in class java.lang.Object
        Parameters:
        obj - The object to compare against this Filter.
        Returns:
        If the other object is a Filter object, then returns the result of calling this.toString().equals(obj.toString(); false otherwise.
      • hashCode

        public int hashCode()
        Returns the hashCode for this Filter.

        This implementation returns the result of calling this.toString().hashCode().

        Specified by:
        hashCode in interface org.osgi.framework.Filter
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        The hashCode of this Filter.