Debugging in STS

Debugging in Spring Tool Suite 
 

To understand what is debugging, let’s first understand what a bug is.

A bug is an error, fault, or flaw in a design, development, or operation of Computer Software that causes misbehavior or incorrect or unexpected results. It is not any type of compile-time error or run-time error. The code will simply run and produces a result, but the result may be unexpected or not what we needed, and it will behave in an unintended way.

What causes a bug in a code?

A bug can be created when writing code. It may be due to incorrect communication about the project and its requirements or I can also be created when the code is written without considering all the possible case scenarios, or sometimes when things were not required when the code was written, but now when the projects scale up, it creates a new bug. 

A bug is always unchecked, and they are sometimes very hard to find; for instance, a user enters an input that the programmer did not expect. It also becomes hard to locate a bug when two or three instances are running together, and you don’t know which of the instance caused an issue.

 
What is Debugging and its need?
 

Debugging is the process of finding the problem within a code and trying to solve it with case scenarios or checking which part of the code caused the bug.

We need debugging so that the problem can be cured within the code, the results a programmer is expecting can be found, and the project will run smoothly back again. A programmer can show an exception occurred when entering a certain input or certain format to enter a value. There are many reasons to debug a code.

Debugging can be a very hard and tiring process as a programmer does not understands what causes the problem initially. Nowadays, IDEs are powerful enough to help the programmer debug and find the problem with the code and fix the code.

Debugging in Spring Tool Suite.

1. Setting up breakpoints

    Break points are the pointers which are put on the line where we want the code to stop/pause the process unless or until we resume back to the normal running state of a program.

    Right-click on the line where you want the program to stop.
    Click on toggle breakpoint.

2. Run the program in Debug mode.
    Right-click on the project and click on debug and select Spring Boot Project.
    A pop-up window will open, which will ask to change the perspective to the debug mode; click yes

3. Controls for programming Execution
     F5 - Executes the current line and moves to the next line.
    F6 – It is used to step over, i.e. to execute a method without stepping into the debugger.
    F7- It is used to step out of the method/function to move to the line where it was previously.
    F8 – It is used to resume the execution of the program to move to the next breakpoint, if any.
 

4. Breakpoint view
    
    Later comes the breakpoint view on the extreme left side of the IDE, where all the lines     where the breakpoint is added can be seen, and you can remove the breakpoints from those lines there as well 
   

5. Changing the values

    At any point while debugging, when you want to change the value that came, you can do that by hovering over it and changing the values to the desired. This also helps to see if there are any other values that you might wanna see or if there is a value you want to change to see what will happen if the only particular value could be changed.

6. Hovering to See the values
    
    Hovering the cursor to the variables before or at the breakpoint and before the ending of the scope at the point where the breakpoint is stopped is used to check the value that the            particular variable is showing is used to check if the desired value is coming till that point or not which can later be used to make different decisions in the code or to check at what      point the values are changing their behaviour.