Question

我的android servlet旨在通过Apache Tomcat服务器上的tomcat servlet发布请求和接收响应。为了进行调试，我使用相同的POST和GET方法设置了Servlet，这样我就可以通过浏览器尝试功能和可访问性。

简而言之：当我部署应用程序时，我可以通过10.0.2.2:8080/my_app?request=test轻松地从AVD设备浏览器访问它，我得到的结果很好。使用localhost:8080/my_app?request=test.从我的机器访问也是如此但是当我从我的应用程序中尝试它时，我总是得到java.io.FileNotFoundException: http://10.0.2.2:8080/my_app。为什么呢？

到目前为止我尝试了什么：该应用程序具有互联网权限，并且它们也可以工作，为了进入Servlet通信点，我必须首先通过PHP进行登录程序，并且它位于同一台服务器上并且正常工作

我连接到servlet的AsyncTask如下所示：

        AsyncTask<Void,Void,String> getDBdata = new AsyncTask<Void, Void, String>() {
            @Override
            protected String doInBackground(Void... params) {
                URL url = null;
                try {
                    url = new URL("http://10.0.2.2:8080/my_app");
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                }
                String text;
                text = null;
                JsonArray js = null;
                try {
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    connection.setDoOutput(true);
                    connection.setRequestMethod("POST");
                    connection.setRequestProperty("action", "getDBData");
                    connection.setDoInput(true);
                    connection.connect();
                    BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                    StringBuilder builder = new StringBuilder();
                    String aux = "";

                    while ((aux = in.readLine()) != null) {
                        builder.append(aux);
                    }
                    text = builder.toString();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return text;

Answer 1

好吧，当然我一直试图在标题中发送参数，这导致了BS。菜鸟错误！

来自this question的回答帮助了我很多调试！另外，从servlet看一下服务器协议可能会让我更早地发现错误。

这是最终有效的代码：

AsyncTask<Void,Void,String> getDBdata = new AsyncTask<Void, Void, String>() {
    @Override
    protected String doInBackground(Void... params) {
        URL url = null;
        try {
            url = new URL(Constants.SERVER_URL + getDBdataURL);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        String text;
        text = null;
        try {
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestProperty("Accept-Charset", "UTF-8");
            connection.setRequestProperty("User-Agent", "Mozilla/5.0 ( compatible ) ");
            connection.setRequestProperty("Accept", "*/*");
            connection.setChunkedStreamingMode(0);
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            connection.setDoOutput(true);
            connection.setRequestMethod("POST");
            String request = "action=getDBdata";
            PrintWriter pw = new PrintWriter(connection.getOutputStream());
            pw.print(request);
            pw.close();
            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            StringBuilder builder = new StringBuilder();
            String aux = "";
            while ((aux = in.readLine()) != null) {
                builder.append(aux);
            }
            text = builder.toString();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return text;
    }

Tomcat连接中AVD中的奇怪FileNotFoundException

1 个答案: