Your class member model from class InputTab has never initialized. Therefore, you got a NPE at line model.requery();. That’s why you saved your data, but right after that, you got a NPE. You don’t need any Cursor in this class and, of course, you don’t need to requery() anything. 2 solved Nullpointer Exception in SQL, … Read more
You would have to do something like this as having an else if after an else for the same block will cause you issues. If this is not the behavior you are looking for please supply more info and I’ll try to help 🙂 int a, b, c; Scanner scan = new Scanner(System.in); System.out.println(“Inserire a”); … Read more
You can simply work with regular expressions. Something like: if(vehicleId.matches(“^[A-Z]{3}\d{4}$”)) (Assuming the id contains three capital letters followed by four digits.) This will return a boolean if vehicleId, supposedly a variable holding the user’s input, is matched. 2 solved How can I check if a String contains X letters and Y numbers? [closed]
When it comes to “current date or time”, it means “randomness”. The reason of the different output of your code is not multi threads, but the new java.util.Date() Thread switching can cause randomness also, but it is very easy to avoid because of the existence of locks. Your code also has lock by using JAVA … Read more
Use this code: @Override public void onClick(View view) { // TODO Auto-generated method stub //public void work (View view){ Intent intent = new Intent(PDFtester.this, copyAsset.class); startActivity(intent);} } Note :- Interfaces like OnClickListener,OnTouchListener etc don’t use this for getting Context try to use YourActivity.this or getApplicationContext() 2 solved calling a method from an onClick listener [duplicate]
You have done for (int b = 0; b<3; i++) instead of the correct for (int b = 0; b<3; b++) This should help your loop terminate. 0 solved How to output random letters in java and get the total, high score and lowest score?
you just have to add an else condition to your if statement in the loop, This should work if the rest of your code works import java.util.Scanner; public class analyzeScores { public static void count(int[] list) { Scanner input = new Scanner(System.in); for(int i = 0; i < list.length;i++) { if(list[i] != 0){ list[i] = … Read more
You have a Menu class, I assume it would be a POJO class. You have different restaurants, each restaurant has it’s own menu. Solution: Don’t save multiple restaurant’s menu in same menu class, have one object for one menu and yes it won’t be inefficient to do so. Reason: The amount of data will be … Read more
This is defined in Chapter 7 of the Java Language Specification (JLS): A compilation unit […] automatically imports all of the public types declared in the predefined package java.lang. solved Why We Don’t Need To Import the java.lang package to use the Integer Class(Wrapper Classes) In Java [duplicate]
I did not understand how the output you showed has one of the numbers multiplied by 100 in each element of String array. Based on my understanding of your question here is a solution. import java.util.Arrays; import java.util.Collections; import java.util.LinkedList; import java.util.stream.Collectors; import java.util.stream.IntStream; public class Shifts { public static void main(String[] args) { LinkedList<Integer> … Read more
You can change the status of the views programmatically. You should use view.setVisibility(View.GONE) if you want to remove the view from the layout, and view.setVisibility(View.INVISIBLE) if you want to hide it. To put them back , use view.setVisibility(View.VISIBLE). solved Hiding specific view in an activity
The dilemma here is that “currently executing object” is a very abstract concept that is easy to intuit but hard to describe in writing (at least for me) If you have a ChildClass, it is also a BaseClass. Therefore, you have a single object in question. Its type is ChildClass, and it can be cast … Read more
You should just Google this stuff. There were plenty of answers out there. But all you have to do is check if (a,b) is the same as (b,a). public static boolean isSymetric(int[][] array){ for(int a = 0; a < array.length; a++){ for(int b = 0; b < array.length; b++){ if(array[a][b]!=array[b][a]){ return false; } } } … Read more
I think you’re implementing wrong Retrofit callback in your code. As I can see you’re receiving first a JSONObject called photos that contains a JSONArray photo, so your code should look like this Call<PhotoResult> call = apiInterface.getImages(query); call.enqueue(new Callback<PhotoResult>() {…} As you can see, the callback object is PhotoResult that is the root level of … Read more
Yes, it can easily be done using recursion. The idea is to check if there is already a node in the tree under which the new node can be fallen. For example, if the new node is “1.1.2”, then we have to check if the node “1.1” exists in the tree. I wrote a very … Read more