android - 如果没有互联网连接，则关闭应用程序

Question

如果没有可用的互联网连接，我正在尝试关闭应用程序。我知道有一个问题已经存在，但是我做的完全一样，而且看来我的应用在注册前可以正常工作，但是如果我在编辑文本后再次打开时在昵称字段中编辑文本，则会抛出空指针错误。看一看 :

我已经在我的应用程序上注册，并且在抽屉中有一个可编辑的昵称，所以我这样做是这样的:

pname = (EditText) findViewById(R.id.pname);

        profimg.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                show();
            }
        });

        pname.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                pname.setInputType(0x0000006);
                pname.setCursorVisible(true);

            }
        });
        pname.setOnFocusChangeListener(new View.OnFocusChangeListener() {
            @Override
            public void onFocusChange(View v, boolean hasFocus) {
                if(hasFocus){
                    pname.setCursorVisible(false);
                }
                else{
                    pname.setCursorVisible(false);
                }
            }
        });

        pname.setOnEditorActionListener(new EditText.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if (event!=null && event.getKeyCode() != KeyEvent.KEYCODE_ENTER || actionId != EditorInfo.IME_ACTION_DONE ) {
                    return false;
                }
                else if(actionId==EditorInfo.IME_ACTION_DONE || event==null || event.getKeyCode() == KeyEvent.KEYCODE_ENTER){

                    pname.setCursorVisible(false);
                    InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
                    imm.hideSoftInputFromWindow(pname.getWindowToken(), 0);
                    return false;
                }
                return false;
            }
        });

 pname.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }

            @Override
            public void afterTextChanged(Editable s) {
                sp.edit().remove("personName").apply();
                name= s.toString();
                sp.edit().putString("personName",name).apply();
                try {
                    List<NameValuePair> params = new ArrayList<NameValuePair>();
                    params.add(new BasicNameValuePair("nickname", name));
                    params.add(new BasicNameValuePair("mobile", callNo));
                    JSONObject json = jsonParser.makeHttpRequest(Config.URL_Info, "POST",
                            params);
                    int success = json.getInt(TAG_SUCCESS);
                    if (success == 1) {
                        Log.d("Status Updated", json.getString(TAG_MESSAGE));
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }

            }
        });
        if(path1) {
            String value = sp.getString("personName", name);
            pname.setText(value);
        }

错误是我设置文本的地方。我在setcontentview(layout)之后的开始处检查连接的可用性，并且该函数仅在onCreate方法之后。

错误日志:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int org.json.JSONObject.getInt(java.lang.String)' on a null object reference                                                                            
                                                                             at .afterTextChanged(PlaceCallActivity.java:206)
                                                                             at android.widget.TextView.sendAfterTextChanged(TextView.java:7942)
                                                                             at android.widget.TextView.setText(TextView.java:4079)
                                                                             at android.widget.TextView.setText(TextView.java:3928)
                                                                             at

Answer 1

您需要检查json变量是否为null
仅当json变量不为null时，才继续执行其他步骤

 @Override
        public void afterTextChanged(Editable s) {
            sp.edit().remove("personName").apply();
            name= s.toString();
            sp.edit().putString("personName",name).apply();
            try {
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("nickname", name));
                params.add(new BasicNameValuePair("mobile", callNo));
                JSONObject json = jsonParser.makeHttpRequest(Config.URL_Info, "POST",
                        params);
                if(json!=null){
                int success = json.getInt(TAG_SUCCESS);
                if (success == 1) {
                    Log.d("Status Updated", json.getString(TAG_MESSAGE));
                }
              }
            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    });