我的HttpUrlConnection尝试写入然后读取时出错

Question

这是我举行HttpURLConnection的地方。我正在尝试将用户名/密码发送到我的php控件，该控件返回true / false结果。

然而，当我添加Buffered Reader时，我一遍又一遍地得到同样的错误。

我看过this帖子，但我仍然不明白。有人可以解释为什么这不起作用吗？

方式：

public boolean checkLogin(String username, String password){
    boolean is_Correct = false;
    try {
        URL url = new URL(this.url);
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        conn.setRequestMethod("POST");
        conn.setDoOutput(true);
        conn.setDoInput(true);
        conn.setUseCaches(false);
        BufferedWriter output = new BufferedWriter(new OutputStreamWriter(conn.getOutputStream(),"UTF-8"));
        output.write("func=Login");
        output.write("username="+username);
        output.write("password="+password);
        BufferedReader input = new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));
        String result = input.readLine();
        output.flush();
        output.close();
    }catch(Exception e){
        e.printStackTrace();
    }
    return is_Correct;
}

错误：

09-19 12:25:27.408 3913-3913/com.project.backgroundprocesstest W/System.err: android.os.NetworkOnMainThreadException
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at java.net.InetAddress.lookupHostByName(InetAddress.java:436)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at java.net.InetAddress.getAllByName(InetAddress.java:215)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.Network$1.resolveInetAddresses(Network.java:29)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:188)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:157)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:100)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.http.HttpEngine.createNextConnection(HttpEngine.java:399)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:379)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:369)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:287)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:457)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:130)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:261)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.project.backgroundprocesstest.HttpConnect$override.checkLogin(HttpConnect.java:38)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.project.backgroundprocesstest.HttpConnect$override.access$dispatch(HttpConnect.java)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.project.backgroundprocesstest.HttpConnect.checkLogin(HttpConnect.java:0)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.project.backgroundprocesstest.LoginControl.checkLogin(LoginControl.java:13)
09-19 12:25:27.410 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.project.backgroundprocesstest.MainActivity$1$override.onClick(MainActivity.java:52)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.project.backgroundprocesstest.MainActivity$1$override.access$dispatch(MainActivity.java)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.project.backgroundprocesstest.MainActivity$1.onClick(MainActivity.java:0)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at android.view.View.performClick(View.java:5210)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at android.view.View$PerformClick.run(View.java:21328)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at android.os.Handler.handleCallback(Handler.java:739)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:95)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at android.os.Looper.loop(Looper.java:148)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5551)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:730)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:620)
09-19 12:25:27.411 3913-3913/com.project.backgroundprocesstest 

Answer 1

如前所述，您需要使用asynctask。在asynctask中，您还可以通过将参数放在HashMap中并使用如下方法来改善与php的通信：

public String performPostCall(String requestURL, HashMap<String, String> postDataParams)
{
    String response = "Network Error.";

   // Log.i(TAG, "performpostcall was run!! yay!");
    try
    {
        URL url = new URL(requestURL);

        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        conn.setReadTimeout(8000);
        conn.setConnectTimeout(8000);
        conn.setRequestMethod("POST");
        conn.setDoInput(true);
        conn.setDoOutput(true);

        OutputStream os = conn.getOutputStream();
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));

        writer.write(getPostDataString(postDataParams));

      //  Log.i(TAG, "getPostDataString() returned " + getPostDataString(postDataParams));

        writer.flush();
        writer.close();
        os.close();

        int responseCode = conn.getResponseCode();
        if (responseCode == 200)
        {
            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = br.readLine()) != null) {
                response = response + line;
            }
        }
        else
        {
            response = "response code: " + responseCode;

        }
        conn.disconnect();
    }
    catch (Exception e)
    {
        //  This should never happen. :)
    }
    return response;
}

和...

private String getPostDataString(HashMap<String, String> params)
        throws UnsupportedEncodingException
{
    StringBuilder result = new StringBuilder();
    boolean first = true;

   // Log.i(TAG, "get PostDataString was run!! yay!");
    for (Map.Entry<String, String> entry : params.entrySet())
    {
        if (first) {
            first = false;
        } else {
            result.append("&");
        }
        result.append(URLEncoder.encode((String)entry.getKey(), "UTF-8"));
        result.append("=");
        result.append(URLEncoder.encode((String)entry.getValue(), "UTF-8"));
    }
    return result.toString();
}

通过这种方式，您可以轻松控制超时，轻松设置参数，并获取有关错误原因的更详细信息。