java - Android - 在 Activity 之间保持用户记录

Question

在我的应用程序中，我有第一个 Activity ，允许您登录网络服务。如果服务器允许用户连接，则应调用 TabHost Activity 。在 TabHost Activity 中，我有 3 个不同的 Activity :

• HomeActivity:它仅显示一个网页 View
• HistoryActivity:它应该显示一个 ListView，我在其中插入通知历史记录
• SettingsActivity:显示应用的一些设置

在 HistoryActivity 中，我必须调用 Web 服务来下载通知历史记录列表。要调用此服务，我必须保持用户登录，我该怎么做？

我使用以下代码连接到历史记录服务:

public void postData(String url) {
    HttpClient httpClient = new DefaultHttpClient();
    HttpPost httpPost = new HttpPost(url);

    try {
        StringEntity  jsonSend = new StringEntity("{\"history\": true}");
        httpPost.setHeader("Content-type", "application/json; charset=UTF-8");
        httpPost.setEntity(jsonSend);
        HttpResponse response = httpClient.execute(httpPost);

        BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
        StringBuilder builder = new StringBuilder();

        for (String line = null; (line = reader.readLine()) != null;) {
            builder.append(line).append("\n");
        }
        String json = builder.toString();
        Log.d("HISTORY", json);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

我用它来登录，效果很好。要连接到登录服务，我使用以下代码:

public void postData(final String username, final String password) {
    HttpClient httpClient = new DefaultHttpClient();
    HttpPost httpPost = new HttpPost(url);

    try {
        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
        nameValuePairs.add(new BasicNameValuePair("username", username));
        nameValuePairs.add(new BasicNameValuePair("password", password));
        nameValuePairs.add(new BasicNameValuePair("pollingId", "XXXXXXXXX"));

        httpPost.setHeader("Content-type", "application/x-www-form-urlencoded");

        httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

        HttpResponse response = httpClient.execute(httpPost);

        BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
        StringBuilder builder = new StringBuilder();

        for (String line = null; (line = reader.readLine()) != null;) {
            builder.append(line).append("\n");
        }

        String json = builder.toString();

        JSONObject jsonObject = new JSONObject(json);
        Boolean success = jsonObject.getBoolean("success");

        if (success == true) {
            MainActivity.this.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(MainActivity.this, "ACCESSO EFFETTUATO!", Toast.LENGTH_LONG).show();
                    Intent i = new Intent(MainActivity.this, TabBarActivity.class);
                    startActivity(i);
                }
            });
        }

    } catch (ClientProtocolException e) {
       Log.d("CLIENT EXCEPTION", "ERRORE: " + e);
    }catch (IOException e) {
       Log.d("I/O EXCEPTION", "ERRORE: " + e);
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

如果我用它来获取通知历史记录，JSON 会告诉我用户未登录。我该如何修复它？谢谢

更新我尝试遵循您的建议，但得到了相同的结果。修改后的代码如下:

MainActivity.java

public void postData(final String username, final String password) {
        HttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost("https://extranet.gruppotesta.it/srv/at-brain/login.jsp");

        try {
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
            nameValuePairs.add(new BasicNameValuePair("username", username));
            nameValuePairs.add(new BasicNameValuePair("password", password));
            nameValuePairs.add(new BasicNameValuePair("pollingId", "XXXXXXX"));

            httpPost.setHeader("Content-type", "application/x-www-form-urlencoded");

            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            HttpResponse response = httpClient.execute(httpPost);

            BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
            StringBuilder builder = new StringBuilder();

            for (String line = null; (line = reader.readLine()) != null;) {
                builder.append(line).append("\n");
            }

            String json = builder.toString();

            JSONObject jsonObject = new JSONObject(json);
            Boolean success = jsonObject.getBoolean("success");

            if (success == true) {
                Header[] cookie = response.getHeaders("cookie");
                SharedPreferences sharedPreferences = getPreferences(Context.MODE_PRIVATE);
                SharedPreferences.Editor editor = sharedPreferences.edit();
                editor.putString("cookie", cookie.toString());
                editor.commit();
                MainActivity.this.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(MainActivity.this, "ACCESSO EFFETTUATO!", Toast.LENGTH_LONG).show();
                        Intent i = new Intent(MainActivity.this, TabBarActivity.class);
                        startActivity(i);
                    }
                });
            }

        } catch (ClientProtocolException e) {
           Log.d("CLIENT EXCEPTION", "ERRORE: " + e);
        }catch (IOException e) {
           Log.d("I/O EXCEPTION", "ERRORE: " + e);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}

HistoryActivity.java

   public void postData(String url) {
        HttpClient httpClient = new DefaultHttpClient();

        SharedPreferences sharedPreferences = getPreferences(Context.MODE_PRIVATE);
        String stringCookie = sharedPreferences.getString("cookie", null);
        BasicCookieStore cookieStore = new BasicCookieStore();
        Cookie cookie = new BasicClientCookie("login", stringCookie);
        cookieStore.addCookie(cookie);

        HttpContext localContext = new BasicHttpContext();
        localContext.setAttribute(ClientContext.COOKIE_STORE, cookieStore);

        HttpPost httpPost = new HttpPost(url);

        try {
            StringEntity jsonRequest = new StringEntity("{\"history\": true}");
            httpPost.setEntity(jsonRequest);
            httpPost.setHeader("Content-type", "application/json; charset=UTF-8");
            httpPost.setHeader("Cookie", cookie.toString());

            HttpResponse response = httpClient.execute(httpPost, localContext);

            BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
            StringBuilder builder = new StringBuilder();

            for (String line = null; (line = reader.readLine()) != null;) {
                builder.append(line).append("\n");
            }
            String json = builder.toString();
            Log.d("HISTORY", json);

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

当我尝试运行应用程序时，服务器回答我错误“用户未登录”。我的代码有什么问题？

Answer 1

当您第一次登录时，网络服务必须为您提供某种访问 token - 也许是一个有效的用户 ID。您需要在 SharedPreference 中存储和检索此用户 ID 。此用户 ID 必须作为参数传递给所有后续 Web 服务，以指示用户确实已登录。

有关如何获取和设置 SharedPreference 的官方教程是 here .