在 kotlin (Android ) 中發送獲取請求

Question

我需要在 Android 應用程序中發送 http 獲取請求。

...
import java.net.HttpURLConnection
import java.net.URL

...

fun sendGet(view: View) {
        val url = URL("http://www.google.com/")

        with(url.openConnection() as HttpURLConnection) {
            requestMethod = "GET"  // optional default is GET

            println("\nSent 'GET' request to URL : $url; Response Code : $responseCode")

            inputStream.bufferedReader().use {
                it.lines().forEach { line ->
                    println(line)
                }
            }
        }
    }
}

顯現

  <uses-permission android:name="android.permission.INTERNET" />
    <application

然后我按發送請求按鈕應用程序崩潰。

日志

2020-06-08 13:37:58.832 7039-7039/com.example.remote E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.remote, PID: 7039 java.lang.IllegalStateException: Could not execute method for android :onClick at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:402) at android.view.View.performClick(View.java:7357) at android.view.View.performClickInternal(View.java:7334 ) at android.view.View.access$3600(View.java:808) at android.view.View$PerformClick.run(View.java:28200) at android.os.Handler.handleCallback(Handler.Z93F725A07423FE1C889F4 48B33D21F46Z:907) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:223) at android.app.ActivityThread.main(ActivityThread.java:7478) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:549) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java :941) 引起：java.lang.reflect.Method.invoke(Native Method) 在 androidx.appcompat.app.AppCompatViewInflater.invoke(Native Method) 在 Z93F725A07423FE1C889F448 pCompatViewInflater.java:397) at android.view.View.performClick(View.java:7357) at android.view.View.performClickInternal(View.java:7334) at android.view.View.access$3600(View.java: 808) at android.view.View$PerformClick.run(View.java:28200) at android.os.Handler.handleCallback(Handler.java:907) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:223) at android.app.ActivityThread.main(ActivityThread.java:7478) at java.lang.reflect. Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:549) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941) Caused by: java.io.IOException: Cleartext HTTP traffic to www.google.com not permitted at com.android.okhttp.HttpHandler$CleartextURLFilter.checkURLPermitted(HttpHandler.java:127) at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute (HttpURLConnectionImpl.java:462) 在 com.ZC31B32364CE19CA8FCD150A417EC CE58Z.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:411) at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:542) at com.example.remote.MainActivity.sendGet( MainActivity.kt:24) at java.lang.reflect.Method.invoke(Native Method) at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:397) at android.view.View.performClick(View. java:7357) at android.view.View.performClickInternal(View.java:7334) at android.view.View.access$3600(View.java:808) at android .view.View$PerformClick.run(View.java:28200) at android.os.Handler.handleCallback(Handler.java:907) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os. Looper.loop(Looper.java:223) at android.app.ActivityThread.main(ActivityThread.java:7478) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$ MethodAndArgsCaller.run(RuntimeInit.java:549) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941)

Answer 1

嘗試這個，

fun sendGet() {
        try {
            //disable the strict mode otherwise perform this operation on netWork Thread
            val policy = StrictMode.ThreadPolicy.Builder().permitAll().build()
            StrictMode.setThreadPolicy(policy)

            // GET Request
            val request = "http://www.google.com/"
            val url = URL(request)
            val conn = url.openConnection()
            conn.doOutput = true
            // Get the response
            val rd = BufferedReader(InputStreamReader(conn.getInputStream()))
            var line: String
            var sResult = ""
            while (rd.readLine().also { line = it } != null) {
                // Process line...
                sResult = "$sResult$line "
            }
            rd.close()
            Log.e("RESULT", sResult)
        } catch (e: Exception) {
            println("Error $e")
        }
    }