5.3.2.2.4 Add Code to the Main.java Tab in the Java Application Project
Now we need to add some code to Main.java. In doing so, you will see the Source Editor’s code completion and code template (abbreviation) features.
1) Select the Main.java tab in the Source Editor. If it isn’t already open, expand SumApp > Source Packages > sumapp in the Projects window and double-click on the item
Main.java.
2) Inside the main() method, replace the comment //TODO code application logic here with the following: int result = Sum
3) Leave the cursor immediately after Sum. In the next step, you will use code completion to turn Sum into SumLibClass.
4) Press Ctrl-Space to open the code completion box. A short list of possible ways to complete the word appears. However, the class that you want, SumLibClass, might not be there.
5) Press Ctrl-Space again to display a longer list of possible matches. SumLibClass should be in this list.
6) Select SumLibClass and press the Enter key. The Apache NetBeans IDE fills in the rest of the class name and also automatically creates an import statement for the class.
7) In the main method, type a period (.) after SumLibClass. The code completion box opens again.
8) Select the sumapp(String args) int method and press the Enter key. The IDE fills in the sumapp() method and highlights the input parameters.
9) Press the Enter key to accept args as the parameter, and change this null to args[0]. Type a semicolon (;) at the end of this code line. The final line should look like the following: int result = SumLibClass.sumapp(args[0]);
10) Press the Enter key to start a new line. Then type the following code line.
System.out.println(“The sum = “+ result);
11) Go to the File > Save All menu item to save the file.
At this point, we are ready to run our Java application project, SumApp, to test its calling func-tion to our Java library file SumLibClass.