Android Volley 请求完全失败

Android Volley Request utterly fails

我正在尝试从 Http 请求获取数据到我自己的 API。 运行 我浏览器中的请求(将 IP 与本地主机交换)让我:

["Herbalism","Mining","Skinning","Alchemy","Blacksmithing","Enchanting","Engineering","Inscription","Jewelcrafting","Leatherworking","Tailoring","Archaeology","Cooking","Fishing"]

我正在使用以下代码,根据此处提供的示例进行修改:https://www.tutorialspoint.com/how-to-use-volley-library-to-parse-json-in-android-kotlin-app 它不打印我的“打印任何东西”。据我所知,这没有任何作用。我已经尝试了很多不同的事情,包括来自这里的建议:Can I do a synchronous request with volley? and here: Volley Timeout Error,我觉得我离让这个请求生效还差得很远。防火墙允许此流量。 catch JSONExceptionResponse.ErrorListener 也没有输出任何东西。我使用的是纯 http,没有证书或任何东西。最终我想用这些数据填充一个微调器,但现在我什至无法让这个最基本的实现工作。

package com.wowahapp

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.*
import androidx.recyclerview.widget.RecyclerView
import com.android.volley.Request
import com.android.volley.RequestQueue
import com.android.volley.Response
import com.android.volley.toolbox.*
import org.json.JSONException


class AddRecipeActivity : AppCompatActivity() {

    lateinit var searchTextView : TextView
    private var requestQueue : RequestQueue? = null


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_add_recipe)


        searchTextView = findViewById<TextView>(R.id.searchTextView) as TextView

        getAllProfessions(searchTextView)

    }

    fun getAllProfessions(searchText : TextView) {

        val url = "http://192.168.0.24:49155/allprofessions"
        val request = JsonObjectRequest(Request.Method.GET, url, null, Response.Listener {
                response ->try {
            val jsonArray = response.getJSONArray("name")
            println("Print anything at all!")
            for (i in 0 until jsonArray.length()) {
                println(jsonArray.getJSONObject(i))
            }
        } catch (e: JSONException) {
            e.printStackTrace()
        }
        }, Response.ErrorListener { error -> error.printStackTrace() })
        requestQueue?.add(request)
    }
}

本文档解释了 VolleyWebService 的实现 class: http://code.sunnyjohn.in/index.php/2020/12/24/retrieve-data-volley/

您必须实例化 class,创建一个新的请求队列,然后添加到请求队列中。

首先创建自定义的VolleyWebServiceclass如下:

class VolleyWebService constructor(context: Context) {
    private var INSTANCE: VolleyWebService? = null
           companion object {
            @Volatile
            private var INSTANCE: VolleyWebService? = null
            fun getInstance(context: Context) =
                INSTANCE ?: synchronized(this) {
                    INSTANCE ?: VolleyWebService(context).also {
                        INSTANCE = it
                    }
                }
        }
    
    val requestQueue: RequestQueue by lazy {
                Volley.newRequestQueue(context.applicationContext)
    }

    fun <T> addToRequestQueue(req: Request<T>) {
        requestQueue.add(req)
    }
}

然后像这样修改您的函数 getAllProfessions:

fun getAllProfessions(searchText : TextView) {

        val url = "http://192.168.0.24:49155/allprofessions"
        val request = JsonObjectRequest(Request.Method.GET, url, null, Response.Listener {
                response ->try {
            val jsonArray = response.getJSONArray("name")
            println("Print anything at all!")
            for (i in 0 until jsonArray.length()) {
                println(jsonArray.getJSONObject(i))
            }
        } catch (e: JSONException) {
            e.printStackTrace()
        }
        }, Response.ErrorListener { error -> error.printStackTrace() })
//changes made here
      VolleyWebService.getInstance(context).addToRequestQueue(request)  
    }
}