使用SharedPreferences保持用户登录

Question

我有一个Java SessionManager类，其中包含许多用于具有sharedPreferences（例如，创建登录会话，清除登录会话等）的不同登录操作的方法。 我也有一个调度活动，该应用在运行时启动。 此调度活动从我的SessionManager类中调用一个方法，以检查用户当前是否已登录。如果他/她已登录，并且意图将其带到我的主要活动中。 否则，将在他们可以登录的地方调用登录活动，等等。但是，每当我运行我的应用程序时，都会出现错误。 我主要活动的代码如下：

public class MainList extends AppCompatActivity {


RecyclerView gradeList;
SwipeRefreshLayout swipeRefreshLayout;
public SessionManager session;

static String tab1 = "studentdata";
static String tab2 = "gradebook";
static String tab3 = "weeklysummary";
static String action = "form";



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_list);
    Log.e("MESSAGE: ", "In second class");

    session = new SessionManager(getApplicationContext());

    setTheme(R.style.AppTheme);


    Toolbar toolbar;
    toolbar = (Toolbar)findViewById(R.id.tb);
    setSupportActionBar(toolbar);

    new infoGetter().execute();

    gradeList = (RecyclerView)findViewById(R.id.grade_list);
    LinearLayoutManager lm = new LinearLayoutManager(getApplicationContext());
    lm.setOrientation(lm.VERTICAL);
    gradeList.setLayoutManager(lm);

    swipeRefreshLayout = (SwipeRefreshLayout)findViewById(R.id.refresh);
    swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
        @Override
        public void onRefresh() {
            refreshGrades();
        }
    });


}


private void refreshGrades(){


    new infoGetter().execute();

    swipeRefreshLayout.setRefreshing(false);

}

@Override
public void onBackPressed() {
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main_list, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

public class Wrapper{
    public Elements gradeList;
}

private class infoGetter extends AsyncTask<Void, Void, Wrapper> {

    String studentID = session.getID();
    String username = session.getUser();
    String password = session.getPass();

    @Override
    protected Wrapper doInBackground(Void... params) {

        Wrapper w = new Wrapper();

        String loginURL = "https://parents.mtsd.k12.nj.us/genesis/parents/j_security_check";
        String userDataUrl = "https://parents.mtsd.k12.nj.us/genesis/parents?tab1=" + tab1 + "&tab2=" + tab2 + "&tab3=" + tab3 + "&studentid=" + studentID + "&action=" + action;

        Connection.Response response = new GradeFetcher().getRequest(userDataUrl);
        Document loggedInDocument = new GradeFetcher().postRequest(loginURL, username, password, studentID, response);
        Elements grades = new GradeFetcher().gradeExtractor(loggedInDocument);

        w.gradeList = grades;
        Log.e("MESSAGE: ","Going to onPostExecute");

        return w;
    }

    protected void onPostExecute(Wrapper w) {

        ArrayList<String>gl = new ArrayList<>();
        for (Element e:w.gradeList){
            gl.add(e.text());
        }

        String[]gradeData = gl.toArray(new String[gl.size()]);

        gradeList = (RecyclerView)findViewById(R.id.grade_list);
        LinearLayoutManager lm = new LinearLayoutManager(getApplicationContext());
        lm.setOrientation(lm.VERTICAL);
        gradeList.setLayoutManager(lm);
        gradeList.setAdapter(new RecyclerAdapter(gradeData));
    }
}
}

我的错误如下：

08-06 21:34:19.970    2010-2010/com.aurum.gradebook E/MESSAGE:﹕ In second class
08-06 21:34:20.018    2010-2010/com.aurum.gradebook E/RecyclerView﹕ No adapter attached; skipping layout
08-06 21:34:20.035    2010-2010/com.aurum.gradebook E/RecyclerView﹕ No adapter attached; skipping layout
08-06 21:34:20.182    2010-2038/com.aurum.gradebook E/GET REQUEST﹕ Making GET request to gradebook page
08-06 21:34:20.183    2010-2038/com.aurum.gradebook E/AndroidRuntime﹕ FATAL              EXCEPTION: AsyncTask #1
Process: com.aurum.gradebook, PID: 2010
java.lang.RuntimeException: An error occured while executing doInBackground()
        at android.os.AsyncTask$3.done(AsyncTask.java:304)
        at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
        at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
        at java.util.concurrent.FutureTask.run(FutureTask.java:242)
        at android.os.AsyncTask$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)
 Caused by: java.lang.IllegalArgumentException: Data value must not be null
        at org.jsoup.helper.Validate.notNull(Validate.java:26)
        at org.jsoup.helper.HttpConnection$KeyVal.value(HttpConnection.java:884)
        at org.jsoup.helper.HttpConnection$KeyVal.create(HttpConnection.java:864)
        at org.jsoup.helper.HttpConnection.data(HttpConnection.java:131)
        at com.aurum.gradebook.GradeFetcher.postRequest(GradeFetcher.java:57)
        at com.aurum.gradebook.MainList$infoGetter.doInBackground(MainList.java:124)
        at com.aurum.gradebook.MainList$infoGetter.doInBackground(MainList.java:109)
        at android.os.AsyncTask$2.call(AsyncTask.java:292)
        at java.util.concurrent.FutureTask.run(FutureTask.java:237)

我已多次检查代码，但找不到错误。 我知道这与我的AsycTask有关，但我真的不知道在哪里。 感谢所有帮助，如有可能，我们会提供赏金。 如果需要，我可以提供其他代码。

我的帖子要求：

public Document postRequest(String loginURL, String username, String password, String studentID, Response res) {

    Document doc = null;

    try {

        doc = Jsoup.connect(loginURL)
                .userAgent("Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.4 Safari/537.36")
                .referrer("https://parents.mtsd.k12.nj.us/genesis/parents?gohome=true")
                .cookies(res.cookies())
                .data("j_username", username)
                .data("j_password", password)
                .post();

        Log.e("POST REQUEST", "Connecting to login page, posting credentials...");


    } catch (IOException ioe) {

        ioe.printStackTrace();

    }

    return doc;

}

Answer 1

我认为您的username或password为空，请检查这些值

您可以从jsoup.org下载jsoup的源代码，然后在HttpConnection.java中找到以下代码

public KeyVal value(String value) {
        Validate.notNull(value, "Data value must not be null");
        this.value = value;
        return this;
    }