Question

我正在尝试连接到网站以接收一些JSON信息。当我使用连接的Nexus 7设备在Android Studio中运行应用程序时，我得到了一个java.io.FileNotFound异常，但是如果我点击找不到的文件的名称，我的浏览器会立即显示响应。这对我来说是一个新的应用程序，但我过去做过类似的工作。在过去的两天里，我一直在尝试多种方法，但似乎无法找到问题所在。当我调用connection.getInputStream（）时，代码会爆炸。所有这些都在AsyncTask中运行。

我的代码

public byte[] getUrlBytes(String urlSpec) throws IOException{
    URL url = new URL(urlSpec);
    // urlSpec: https://api.weather.gov/points/48.0174,-115.2278

    try {
        connection = (HttpsURLConnection) url.openConnection();
    } catch (IOException ioe) {
        Log.d(TAG, "connection ioe: " + ioe.toString());
        Toast.makeText(context, "@string/can_not_connect",
                Toast.LENGTH_LONG).show();
    }


    try {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        InputStream in = connection.getInputStream(); *** Blows up here ****

        if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
            Log.d(TAG, "connection Response code: " + 
                  connection.getResponseMessage());
        }

        int bytesRead = 0;
        byte[] buffer = new byte[1024];
        while ((bytesRead = in.read(buffer)) > 0) {
            out.write(buffer, 0, bytesRead);
        }

        out.close();
        return out.toByteArray();
    } finally {
        connection.disconnect();
    }
}

logcat的

04-02 15:40:59.693 32471-32495/com.drme.weathertest E/WeatherFetcher: Failed 
 to fetch items
java.io.FileNotFoundException: https://api.weather.gov/points/48.0174,-115.2278 
*** Note that if I click on this file name, it works in my browser ***
    at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:206)       
    at com.android.okhttp.internal.http.DelegatingHttpsURLConnection.getInputStream(DelegatingHttpsURLConnection.java:210)   
    at com.android.okhttp.internal.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:25)
    at com.drme.weatherNoaa.WeatherFetcher.getUrlBytes(WeatherFetcher.java:148)
    at com.drme.weatherNoaa.WeatherFetcher.getUrlString(WeatherFetcher.java:183)
    at com.drme.weatherNoaa.WeatherFetcher.downloadGridPoints(WeatherFetcher.java:202)
    at com.drme.weatherNoaa.WeatherFetcher.requestForecast(WeatherFetcher.java:262)
    at com.drme.weatherNoaa.WeatherFragment$SearchTask.doInBackground(WeatherFragment.java:329)
    at com.drme.weatherNoaa.WeatherFragment$SearchTask.doInBackground(WeatherFragment.java:296)
    at android.os.AsyncTask$2.call(AsyncTask.java:292)
    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
    at java.lang.Thread.run(Thread.java:818)

感谢您的帮助。

Answer 1

在额外阅读了webservice文档（其中一些对我来说似乎有点薄）以及网上的一些额外帖子之后，答案是它们在请求中需要Acceptance和User-agent标头。我已经做了这些更改，现在代码正常工作。

新的静态常量

private static final String ACCEPT_PROPERTY = "application/geo+json;version=1";
private static final String USER_AGENT_PROPERTY = "xxxx.com (xxxxxxxxx@gmail.com)";

代码更改

 connection = (HttpsURLConnection) url.openConnection();
 connection.setRequestProperty("Accept", ACCEPT_PROPERTY);  // added
 connection.setRequestProperty("User-Agent", USER_AGENT_PROPERTY); // added

不需要进行其他更改，但我花了一些时间来弄清楚如何添加标题以及它们的格式可能是什么。

感谢您查看此内容。

Android Studio中的FileNotFoundException，但在浏览器中工作正常

1 个答案: