本文整理了Java中org.apache.jena.sparql.algebra.Algebra类的一些代码示例，展示了Algebra类的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Algebra类的具体详情如下：
包路径：org.apache.jena.sparql.algebra.Algebra
类名称：Algebra

Algebra介绍

[英]Utilities to produce SPARQL algebra
[中]生成SPARQL代数的实用程序

代码示例

代码示例来源：origin: SmartDataAnalytics/jena-sparql-api

public static Op toOp(String queryStr) {
  Query query = QueryFactory.create(queryStr, Syntax.syntaxSPARQL_11);
  Op result = Algebra.compile(query);
  return result;
}

代码示例来源：origin: SmartDataAnalytics/jena-sparql-api

public static SparqlView create(String name, QuadPattern quadPattern, Element element) {
  Op tmp = Algebra.compile(element);
  Op op = Algebra.toQuadForm(tmp);
  SparqlView result = create(name, quadPattern, op);
  return result;
}

代码示例来源：origin: apache/jena

static public QueryIterator exec(Op op, Dataset ds)
{
  return exec(op, ds.asDatasetGraph()) ;
}

代码示例来源：origin: apache/jena

private static void outputAlgebraOptQuads(ServletOutputStream outStream, final Query query, boolean lineNumbers) throws IOException
{
  outStream.println("<p>Alebgra, with general quads optimizations:</p>") ;
  final Op op = Algebra.optimize(Algebra.toQuadForm(Algebra.compile(query))) ;
  outputQueryOp(outStream, query, op, lineNumbers) ;
}

代码示例来源：origin: apache/jena

private static void outputAlgebraOpt(ServletOutputStream outStream, final Query query, boolean lineNumbers) throws IOException
{
  outStream.println("<p>Alebgra, with general triple optimizations:</p>") ;
  final Op op = Algebra.optimize(Algebra.compile(query)) ;
  outputQueryOp(outStream, query, op, lineNumbers) ;
}

代码示例来源：origin: apache/jena

/** query->algebra/quads->OpAsQuery->query */
private static Query[] roundTripQueryQuad(String query) {
  Query orig = QueryFactory.create(query, Syntax.syntaxSPARQL_11);
  Op toReconstruct = Algebra.compile(orig);
  toReconstruct = Algebra.toQuadForm(toReconstruct);
  Query got = OpAsQuery.asQuery(toReconstruct);
  Query[] r = { orig, got };
  return r;
}

代码示例来源：origin: apache/jena

private void checkRename(String queryString, String opExpectedString)
{
  Op opExpected = SSE.parseOp(opExpectedString) ;
  queryString = "PREFIX : <http://example/>\n"+queryString ;
  Query query = QueryFactory.create(queryString) ;
  Op op = Algebra.compile(query) ;
  Op opRenamed = TransformScopeRename.transform(op) ;
  assertEquals(opExpected, opRenamed) ;
}

代码示例来源：origin: apache/jena

private static void test(String patternString, boolean optimize, String... strExpected)
  {
    Query q = QueryFactory.create("SELECT * WHERE "+patternString) ;
    Op op = Algebra.compile(q) ;
    if ( optimize )
      op = Algebra.optimize(op) ;
    op = Algebra.toQuadForm(op) ;
    Op op2 = SSE.parseOp(StrUtils.strjoinNL(strExpected)) ;
    assertEquals(op2, op) ;
  }
}

代码示例来源：origin: apache/jena

protected Op createOp(Query query)
{
  Op op = Algebra.compile(query) ;
  return op ;
}

代码示例来源：origin: apache/jena

@Override
protected Op modifyOp(Op op)
{ 
  op = super.modifyOp(op) ;
  op = Algebra.toQuadForm(op) ;
  return op ;
}

代码示例来源：origin: apache/jena

public static void checkOp(Query query, boolean optimizeAlgebra)
{
  IndentedLineBuffer buff = new IndentedLineBuffer() ;
  Op op = Algebra.compile(query) ;
  if ( optimizeAlgebra )
    op = Algebra.optimize(op) ;
  WriterSSE.out(buff, op, query) ;
  String str = buff.toString() ;
  
  try {
    Op op2 = SSE.parseOp(str) ;
    if ( op.hashCode() != op2.hashCode() )
    {
      op.hashCode() ;
      op2.hashCode() ;
      dump(op, op2) ;
      throw new QueryCheckException("reparsed algebra expression hashCode does not equal algebra from query") ;
    }
    if ( ! op.equals(op2) )
    {
      dump(op, op2) ;
      throw new QueryCheckException("reparsed algebra expression does not equal query algebra") ;
    }
  } catch (SSEParseException | BuildException ex)
  { 
    System.err.println(str);
    throw ex ; 
  }      // Breakpoint
}

代码示例来源：origin: apache/jena

protected Op op(String pattern, Mode mode) {
    Op op = SSE.parseOp(pattern) ;
    if ( mode == Mode.QUADS )
      op = Algebra.toQuadForm(op) ;
    else if ( mode == Mode.QUADBLOCKS )
      op = Algebra.toQuadBlockForm(op) ;
    return op ;
  }
}

代码示例来源：origin: apache/jena

private static ResultSet exec(String pattern, Graph graph)
{
  Op op = SSE.parseOp(pattern, pmap) ;
  List<Var> vars =  new ArrayList<>() ;
  vars.addAll(OpVars.visibleVars(op)) ;
  QueryIterator qIter = Algebra.exec(op, graph) ;
  return ResultSetFactory.create(qIter, Var.varNames(vars)) ;
}

代码示例来源：origin: apache/jena

private static void check(Op opToOptimize, String opExpectedString) {
  Op opOptimize = Algebra.optimize(opToOptimize) ;
  Op opExpected = SSE.parseOp(opExpectedString) ;
  if ( false ) {
    // Hook for more detail during development. 
    boolean b = Objects.equals(opExpected, opOptimize) ;
    if ( ! b ) {
      System.err.println("** Input:");
      System.err.print(opToOptimize) ;
      System.err.println("** Expected:");
      System.err.print(opExpected) ;
      System.err.println("** Actual:");
      System.err.print(opOptimize) ;
      System.err.println("-------------------") ;
    }
  }
  assertEquals(opExpected, opOptimize) ;
}

代码示例来源：origin: SmartDataAnalytics/jena-sparql-api

@Override
  protected Binding computeNext() {
    while(bindings.hasNext()) {
      List<Binding> cand = bindings.next();

      Binding r = null;
      for(Binding b : cand) {
        if(r == null) {
          r = b;
        } else {
          boolean isCompatible = Algebra.compatible(r, b);
          if(isCompatible) {
            r = Algebra.merge(r, b);
          } else {
            continue;
          }
        }
      }

      return r;
    }

    return endOfData();
  }
}

代码示例来源：origin: apache/jena

/** Apply static transformations to a query to optimize it */
public static Op optimize(Op op) { return optimize(op, null) ; }

代码示例来源：origin: apache/jena

@Override
public boolean containsCompatibleWithSharedDomain(Binding bindingLeft)
{
  if ( commonVars.size() == 0 )
    return false ;
  for ( Binding bindingRight: table )
  {
    if ( hasCommonVars(bindingLeft, bindingRight)
        && Algebra.compatible(bindingLeft, bindingRight) )
      return true ;
  }
  return false ;
}

代码示例来源：origin: apache/jena

if ( Algebra.disjoint(bindingLeft, bindingRight) )
if ( ! Algebra.compatible(bindingLeft, bindingRight) )

代码示例来源：origin: SmartDataAnalytics/jena-sparql-api

public static void main(String[] args) {
  //String sA = "Select * { ?s ?p ?o . Filter((?s || ?p) && ?o) . }";
  //String sA = "Select * { ?s ?p ?o . Filter((?s || ?p) && !(?o || ?g)) . }";
  String sA = "Select * { ?s ?p ?o . Filter(?o != <http://Person>). Optional { { ?x ?y ?z . Filter(?x != <http://x> && ?x = ?y) . } Union { ?x a ?y . Filter(?x = <http://x>) . } } . }";
  //String sA = "Select * { ?s ?p ?o . Filter(!(?s = ?p || ?p = ?o && ?s = ?o || ?o = ?s)) . }";
  //String sA = "Select * { ?s ?p ?o . Filter(!(?s = ?p || ?j = <http://x>)) . }";
  Query qA = QueryFactory.create(sA);
  Op opA = Algebra.compile(qA);
  opA = Algebra.toQuadForm(opA);
  System.out.println(opA);
  // How to deal with union? variables appearing in them
  //System.out.println(opA.getClass());
  ExprList exprs = FilterUtils.collectExprs(opA, new ExprList());
  ExprList proc = eval(exprs);
  System.out.println(proc);
  List<ExprList> clauses = dnfToClauses(proc);
  System.out.println("Mentioned vars:" + proc.getVarsMentioned());
  System.out.println("Clauses: " + clauses);
}

代码示例来源：origin: apache/jena

@Test
public void testTable2() {
  // JENA-1468 : op to string and back.
  String qs = "SELECT * WHERE { ?x ?p ?z . VALUES ?y { } }" ;
  Query query = QueryFactory.create(qs); 
  Op op = Algebra.compile(query);
  String x = op.toString();
  Op op1 = SSE.parseOp(x);
  Query query2 = OpAsQuery.asQuery(op1);
  assertEquals(query, query2);
}