java - 致命异常 : AsyncTask #1 java. lang.RuntimeException:执行 doInBackground() 错误时发生错误

Question

抱歉，这是第二次发布此问题，几年前我的代码运行良好，当我现在尝试运行它时，出现了此问题

08-07 06:04:44.801: E/AndroidRuntime(20161): FATAL EXCEPTION: AsyncTask #1
08-07 06:04:44.801: E/AndroidRuntime(20161): Process: com.parents.track, PID: 20161
08-07 06:04:44.801: E/AndroidRuntime(20161): java.lang.RuntimeException: An error occurred while executing doInBackground()
08-07 06:04:44.801: E/AndroidRuntime(20161):    at android.os.AsyncTask$3.done(AsyncTask.java:309)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at java.util.concurrent.FutureTask.run(FutureTask.java:242)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at java.lang.Thread.run(Thread.java:818)
08-07 06:04:44.801: E/AndroidRuntime(20161): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int org.json.JSONObject.getInt(java.lang.String)' on a null object reference
08-07 06:04:44.801: E/AndroidRuntime(20161):    at com.parents.track.LoginActivity$LogIn.doInBackground(LoginActivity.java:89)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at com.parents.track.LoginActivity$LogIn.doInBackground(LoginActivity.java:1)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at android.os.AsyncTask$2.call(AsyncTask.java:295)
08-07 06:04:44.801: E/AndroidRuntime(20161):    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
08-07 06:04:44.801: E/AndroidRuntime(20161):    ... 4 more

<小时/>

class LogIn extends AsyncTask<String,Void,String >{

    private JsonParser jsonParser;

    @Override
    protected String doInBackground(String... arg0) {
        jsonParser = new JsonParser();
        String url = "http://localhost/track/login.php?phone=";
        StringBuilder urlStringBuilder = new StringBuilder(url);
        urlStringBuilder.append(arg0[0]);
        SessionManager sessionManager=new SessionManager(context);

        JSONObject json = jsonParser.getJsonObject(urlStringBuilder, "GET");
        int isLongedIn=0;
        try {
            isLongedIn=json.getInt("LogedIn");
            if(isLongedIn==1){
            String sesion=json.getString("Message");
            sessionManager.createLoginSession(sesion);
            Intent intent=new Intent(context,WelcomeActivity.class);
            Bundle extra = new Bundle();
            extra.putString("HP",phone.getText().toString());
             intent.putExtras(extra);
            startActivity(intent);
            }else{
                Intent intent=new Intent(context,LoginActivity.class);
                startActivity(intent);
            }

        } catch (JSONException e) {
            // TODO Auto-generated catch block
            Log.w("Json Error", e.toString());
            e.printStackTrace();
        }


        return null;
    }
}

Answer 1

检查您的服务器响应，找不到“已登录”在这一行中: isLongedIn=json.getInt("LogedIn");添加默认 isLongedIn=json.getInt("LogedIn",0);并检查响应是否有名为“LogedIn”的记录