Shape3D triangleLine = new Shape3D();
    Point3d[] triangleLineCoordinates = {
               new Point3d( 0.0, -0.6928, 0.0 ),
               new Point3d( -0.6, 0.3464, 0.0 ),
               new Point3d( 0.6, 0.3464, 0.0 ),
               };
    int[] vertexIndices = new int[triangleLineCoordinates.length + 1];
    for(int i = 0; i < triangleLineCoordinates.length; i++){vertexIndices[i] = i;}
    vertexIndices[triangleLineCoordinates.length] = 0;
    int[] vertexCounts = {(vertexIndices.length)};    // ※1
    IndexedLineStripArray triangleLineGeom = new IndexedLineStripArray(
      triangleLineCoordinates.length,
      IndexedLineStripArray.COORDINATES,
      vertexIndices.length,
      vertexCounts                   // ※1
    );
    triangleLineGeom.setCoordinates( 0, triangleLineCoordinates );
    triangleLineGeom.setCoordinateIndices(0, vertexIndices);
    triangleLine.setGeometry( triangleLineGeom );
    transformGroup.addChild( triangleLine );

※1の部分で、配列変数を作らず、直接パラメータに指定することは出来ますか?
出来るようであれば、教えてください。