Question

这是我从URL读取内容然后将其添加到arraylist中的代码。当我调试它时显示sb.append（line）获取字符串但在此之后，ArrayList数据大小= 0.因此，添加sb不起作用对我来说真的很混乱。我怎么能解决它？

var arrayListData = ArrayList<String>()
var config: Config = Config()

inner class GetData: AsyncTask<Void, Void, ArrayList<String>>() {
    override fun doInBackground(vararg params: Void?): ArrayList<String> {
        val link = arrayOf(config.urlStatus, config.urlTongquan, config.urlBanggia)
        for (i in 0 until link.size){
            getContentURL(link[i])
        }
        return arrayListData
    }

    override fun onPostExecute(result: ArrayList<String>) {
        super.onPostExecute(result)
        Toast.makeText(this@MainActivity, result[1], Toast.LENGTH_SHORT).show()
    }
}

private fun getContentURL(url: String?) : ArrayList<String> {
    var sb = StringBuilder()
    val url = URL(url)
    val urlConnection: HttpURLConnection = url.openConnection() as HttpURLConnection
    val inputStream: InputStream = urlConnection.inputStream
    val isr = InputStreamReader(inputStream)
    val br = BufferedReader(isr)

    var line: String? = ""
    try {
        do {
            line = br.readLine()
            if(line != null){
                sb.append(line)
                arrayListData.add(sb.toString())
            }
        }while (line != null)
        br.close()
    }catch (e: Exception){
        Log.d("AAA", e.toString())
    }
    return arrayListData
}

Answer 1

将您的代码更改为以下代码：

for (i in 0 until link.size){
                arrayListData.add(getContentURL(link[i]))
            }

然后从getContentURL（）返回字符串，如下所示：

private fun getContentURL(url: String?) : String {
    var sb = StringBuilder()
    val url = URL(url)
    val urlConnection: HttpURLConnection = url.openConnection() as HttpURLConnection
    val inputStream: InputStream = urlConnection.inputStream
    val isr = InputStreamReader(inputStream)
    val br = BufferedReader(isr)

    var line: String? = ""
    try {
        do {
            line = br.readLine()
            if(line != null){
                sb.append(line)

            }
        }while (line != null)
        br.close()
    }catch (e: Exception){
        Log.d("AAA", e.toString())
    }
    return sb.toString()
}

如何将内容从url读取添加到arraylist

1 个答案: