1 /*
2  * Copyright (C) 2020 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.statementservice.network.retriever
18 
19 import android.net.Network
20 import android.net.TrafficStats
21 import android.util.Log
22 import com.android.statementservice.utils.Result
23 import kotlinx.coroutines.Dispatchers
24 import kotlinx.coroutines.async
25 import kotlinx.coroutines.withContext
26 import java.net.HttpURLConnection
27 import java.net.URL
28 import java.nio.charset.Charset
29 import javax.net.ssl.HttpsURLConnection
30 
31 class UrlFetcher {
32 
33     companion object {
34         private val TAG = UrlFetcher::class.java.simpleName
35     }
36 
37     suspend fun fetch(
38         url: URL,
39         connectionTimeoutMillis: Int,
40         fileSizeLimit: Long,
41         network: Network? = null
42     ) = withContext(Dispatchers.IO) {
43         TrafficStats.setThreadStatsTag(Thread.currentThread().id.toInt())
44         @Suppress("BlockingMethodInNonBlockingContext")
45         val connection =
46             ((network?.openConnection(url) ?: url.openConnection()) as HttpsURLConnection)
47         try {
48             connection.apply {
49                 connectTimeout = connectionTimeoutMillis
50                 readTimeout = connectionTimeoutMillis
51                 useCaches = true
52                 instanceFollowRedirects = false
53                 addRequestProperty("Cache-Control", "max-stale=60")
54             }
55             val responseCode = connection.responseCode
56             when {
57                 responseCode != HttpURLConnection.HTTP_OK -> {
58                     Log.w(TAG, "The responses code is not 200 but $responseCode")
59                     Result.Success(Response(responseCode))
60                 }
61                 connection.contentLength > fileSizeLimit -> {
62                     Log.w(TAG, "The content size of the url is larger than $fileSizeLimit")
63                     Result.Success(Response(responseCode))
64                 }
65                 else -> {
66                     val content = async {
67                         connection.inputStream
68                             .bufferedReader(Charset.forName("UTF-8"))
69                             .readText()
70                     }
71 
72                     Result.Success(Response(responseCode, content.await()))
73                 }
74             }
75         } catch (ignored: Throwable) {
76             Result.Failure(ignored)
77         } finally {
78             connection.disconnect()
79         }
80     }
81 
82     data class Response(
83         val responseCode: Int,
84         val content: String? = null
85     )
86 }
87