20165202 experiment a familiarity with the Java development environment

I. Contents and steps of the experiment (i) compiling and running a simple Java program using the JDK

• Set up a catalogue of "self-study number EXP1"
  mkdir 20165202exp1

• Go to Catalog
  cd 20165202exp1

• Set up Src,bin and other directories under "EXP1"
  mkdir binmkdir src

• Vim Edit Code
  vi Hello.java

• Javac,java's execution in the "self-study number EXP1" directory
  javac -d bin src/Hello.java

• Run the program
  java Hello

• Run
  

• Code Cloud Link

(ii) Use idea to edit, compile, run, and debug Java programs

• To set a breakpoint, simply click on the line number where you want to set the breakpoint to use it. Alt+Shift+F9Debugging Java programs with shortcut keys

• Single-step operation there are two: Step Into (Fast F7) and Step Over (Fast F8) in the actual use of our priority Step Over , only method execution error, indicating that the program problem in the called method, then come back by Step Into entering the method to debug.

• Temporary breakpoints: The simplest way is to move the cursor to the line where you want to add a breakpoint, use the menu "run"->"toggle temporary the lines breakpoint", or use the shortcut keyCtrl+Alt+Shift+F8

• Conditional breakpoint: Right-click at the left breakpoint on line 9th, pop-up the breakpoint property box, we set the condition "i==50"

• Method Breakpoint: Moves the cursor to any line in the method, using the menu "run"->"toggle method breakpoint

(iii) exercises (implemented via command line and idea two, and debugged using idea)

Implement Fibonacci sequence function and test (normal, abnormal, boundary condition)

• Program code

  1 import java.util.Scanner;  2   3 public class fibonacci {  4   5     public static void main(String[] args) {  6   7         Scanner scanner = new Scanner(System.in);  8   9         System.out.println("请输入一个整数：");  10   11         int n = scanner.nextInt();  12   13         System.out.println("fibonacci数列为：");  14         if(n<=0) {  15             System.out.println("非法输入");  16         }  17         else {  18           for (int j = 1; j <= n; j++) {  19   20             System.out.println(" a["+j+"] =  "+fibonacci(j));  21   22           }  23         }  24         scanner.close();  25   26     }  27   28     private static int fibonacci(int i) {  29   30         if (i == 1 || i == 2){  31   32             return 1;  33   34         }else{  35   36             return fibonacci(i - 1) + fibonacci(i - 2);  37   38         }  39   40     }  41   42 }

• Command line run:

(1) Normal condition

(2) Abnormal situation

(3) Boundary conditions

Code Cloud Link

• Idea Run:

(1) Normal condition

(2) Abnormal situation

(3) Boundary conditions

• Idea Debug

  Single-Step debugging: Set breakpoints on lines 6th and 9

方法断点：在第4、23行设置断点

Ii. problems encountered in the course of the experiment

Start writing Exercise Code Fibonacci Implementation Error Understanding test instructions, output value is the corresponding number of f function

Then only the first n items (for example, 20) can be output, combined with the use of previously learned scanner
Scanner scanner = new Scanner(System.in); System.out.println("请输入一个整数："); int n = scanner.nextInt();
The call resolved an issue where n could not be changed by the input

Third, the experiment experience and summary

Statistics PSP (Personal software Process) Time:

TD align= "Center" >2.5% TD align= "Center" >10%

step	time-consuming	Hundred Division
demand analysis	2min
design	8min
code implementation	25min	31.25%
test	5min	6.25%
Analysis summary	40min	50%

Personal Summary
This experiment content is more basic, mainly examines the Java development environment familiar and some basic operation. Programming has a complete set of processes: analysis requirements, design, code implementation, testing, summary, this is our future programming a basic framework. Learning to master the relevant usage of idea in the course of the experiment is really more useful than the VIM command line, and the debugging process is displayed more clearly. Typing the textbook code on a weekly basis is just one of the most basic tasks, and in practical applications I find it necessary to combine more thinking and understanding to really "learn to apply" and not mechanically "knock on the code".

20165202 experiment a familiarity with the Java development environment