Try-Catch JSON 数组空指针什么也没捕获

Question

如果 jsonarray 为空，我不想捕获任何内容。这是我的代码：

try {
                    for (int i = 0; i < jsonArray.length(); i++) {
                        JSONObject customer = jsonArray.getJSONObject(i);
                        int sender = customer.getInt("sender");
                        Log.e("Customer", "is " + jsonArray.getJSONObject(i));
                        TextView tv[] = new TextView[jsonArray.length()];
                        tv[i] = new TextView(ChatActivity.this);
                        Log.i("Sender", "is " + sender);
//                    Log.i("Curernt ID", "is " + currentUserId);
//                    Log.i("Logged in", " ID is " + sharedPrefsUser.getInt(SharedPrefsInformation.ID_FROM_LOGGED_IN_USER, -1));
//                    Log.i("")
                        if (sharedPrefsUser.getInt(SharedPrefsInformation.ID_FROM_LOGGED_IN_USER, -1) == sender) {
                            tv[i] = (TextView) getLayoutInflater().inflate(R.layout.messae, null);
                        } else {
                            tv[i] = (TextView) getLayoutInflater().inflate(R.layout.message_other, null);
                        }
                        tv[i].setText(customer.getString("message"));
                        Log.e("Message", "is " + customer.getString("message"));
                        linearLayoutWithMessages.addView(tv[i]);
                }
            } catch (JSONException e) {
                return;
            }

但是现在应用程序会崩溃，因为jsonArary 是空的（Nullpointer）。有什么建议，可以调用 Toast 或其他方法来防止应用程序崩溃吗？谢谢:-)

Answer 1

如果 jsonArray 为空，您可以在 for 之前检查或为 Null Pointer 添加一个新的 catch

try {  
    for (int i = 0; i < jsonArray.length(); i++) {  
        JSONObject customer = jsonArray.getJSONObject(i);
        ...
} catch (JSONException e) {
    return;
} catch (NullPointerException npe) {
    //do something
}

Try-Catch JSON 数组空指针什么也没捕获

Try-Catch JSONArray Nullpointer catch nothing

android

try-catch