Class QueryContext


  • public class QueryContext
    extends java.lang.Object
    A QueryContext provides a means to pass arbitrary local state to a Function or TupleFunction. The implementation of org.eclipse.rdf4j.sail.SailConnection#evaluate() is responsible for initialising a QueryContext and making it available during evaluation via QueryContextIteration. A QueryContext is commonly used to provide a QueryPreparer for the current SailConnection. This allows, for example, Functions to be written that conveniently express more complex queries.
    • Field Detail

      • QUERY_PREPARER_ATTRIBUTE

        private static final java.lang.String QUERY_PREPARER_ATTRIBUTE
      • queryContext

        private static final java.lang.ThreadLocal<QueryContext> queryContext
      • attributes

        private final java.util.Map<java.lang.String,​java.lang.Object> attributes
    • Constructor Detail

      • QueryContext

        public QueryContext()
    • Method Detail

      • getQueryContext

        public static QueryContext getQueryContext()
      • begin

        public void begin()
      • setAttribute

        public void setAttribute​(java.lang.String name,
                                 java.lang.Object value)
      • getAttribute

        public <T> T getAttribute​(java.lang.String name)
      • end

        public void end()