Class FilterImpl

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

abstract class FilterImpl extends Object implements 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 Details

    • filterString

      private transient String filterString
  • Constructor Details

    • FilterImpl

      FilterImpl()
  • Method Details

    • createFilter

      static FilterImpl createFilter(String filterString) throws 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:
      InvalidSyntaxException - If the filter parameter contains an invalid filter string that cannot be parsed.
    • match

      public boolean match(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 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(Dictionary<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 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:
      IllegalArgumentException - If dictionary contains case variants of the same key name.
    • matchCase

      public boolean matchCase(Dictionary<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 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(Map<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 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(Map<String,?> map)
    • toString

      public 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 Filter
      Overrides:
      toString in class Object
      Returns:
      This Filter's filter string.
    • normalize

      abstract StringBuilder normalize(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(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 Filter
      Overrides:
      equals in class 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 Filter
      Overrides:
      hashCode in class Object
      Returns:
      The hashCode of this Filter.