在web方法和jason中转换byte []

Question

我试图使用web方法从DB获取byte []数组现在如何使用java脚本调用函数将该字节[]转换并打开为PDF文件

我的网络方法

 override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        let touch = touches.first as! UITouch
        if(touch.view == self.sceneView){
            print("touch working")
            let viewTouchLocation:CGPoint = touch.location(in: sceneView)
            guard let result = sceneView.hitTest(viewTouchLocation, options: nil).first else {
                return
            }
            if myObjectNodes.contains(result.node) { //myObjectNodes is declared as  Set<SCNNode>
                print("match")
            }

        }
    }