20165219 "Java Programming" Experiment 3 (Agile Development and XP Practice) Experiment Report

20165219 "Java Programming" Experiment 3 (Agile Development and XP Practice) Experiment Report

The cover of the lab report

Course: Java Programming Class: Class 1652 Name: Wang Yanbo Student Number: 20165219 Achievement:

Instructor: Lou Jiapeng Experiment date: April 30, 2018
Experiment time: 15:45 - 17:20

Experiment No.: Experiment 3
Experiment Name: Agile Development and XP Practice

Experiment content:

1. XP Basics

2. XP Core Practices

3. Related tools

Experimental requirements:

1 Students who do not have Linux foundation are recommended to study the courses of "Introduction to Linux Basics (New Edition)" and "Vim Editor";

2 Complete the experiment and write the experimental report, pay attention to the experimental report focusing on the operation results, the problems encountered (tool search, installation, use, program editing, debugging, running, etc.), solutions (empty methods such as "check the network", "Ask a classmate", "read a book", etc. will all get 0 points) and analysis (what inspiration can be obtained from it, what can be gained, lessons, etc.);

3. Count your own PSP (Personal Software Process) time in the experimental report;

4 Plagiarism is strictly prohibited.

2. Experiment content and steps

(1) alibaba plugin and Code menu

Move Line/statement Down/Up: Move a line or expression down or up one line

Surround with: wrap statements with try-catch, for, if, etc.

comment with line/block comment: Turn the selected area into a comment

show reformat file dialog: automatically align according to the format

Optimize imports: optimize imports

Insert Live Template: Insert Live Template abbreviation

For example: comment with line/block comment, turn the selected part of the code into a comment

(2) Complex code to add test cases

companion code

public class Complex {
    // 定义属性并生成getter,setter
    private double r;
    private double i;

    // 定义构造函数
    public Complex(double r, double i) {
        this.r = r;
        this.i = i;
    }

    public static double getRealPart(double r) {
        return r;
    }

    public static double getImagePart(double i) {
        return i;
    }

    //Override Object
    public boolean equals(Object obj) {

        Complex complex = (Complex) obj;
        if (complex.r != r) {
            return false;
        }
        if (complex.i != i) {
            return false;
        }
        return true;
    }

    public String toString() {
        String str = new String();
        if (i == 0) str = r + "";
        else if (i < 0) str = r + "" + i + "i";
        else str = r + "" + "+" + i + "i";
        return str;
    }

    // 定义公有方法:加减乘除
    Complex ComplexAdd(Complex a) {
        return new Complex(r + a.r, i + a.i);
    }

    Complex ComplexSubtract(Complex a) {
        return new Complex(r - a.r, i - a.i);
    }

    Complex ComplexMultiply(Complex a) {
        return new Complex(r * a.r - i * a.i, r * a.i + i * a.r);
    }

    Complex ComplexDivide(Complex a) {
        return new Complex((r * a.r + i * a.i) / (a.r * a.r + a.i * a.i), (i * a.r - r * a.i) / (a.r * a.r + a.i * a.i));
    }
}

Add test case

import junit.framework.TestCase;
import org.junit.Test;
import static org.junit.Assert.*;
public class ComplexTest extends TestCase {
  Complex a=new Complex(1,2);
  Complex b=new Complex(-2,-1);
  Complex d=new Complex(4,-2);
  @Test
  public void testequals(){
      assertEquals(false,a.equals(b));
      assertEquals(false,b.equals(c));
      assertEquals(true,new Complex(1.0,2.0).equals(a));
  }

  @Test
  public void testAdd(){
      assertEquals(new Complex(-1,1),a.ComplexAdd(b));
      assertEquals(new Complex(5,0),a.ComplexAdd(c));
  }
  @Test
  public void testSubtract(){
      assertEquals(new Complex(3,3),a.ComplexSubtract(b));
      assertEquals(new Complex(-3,4),a.ComplexSubtract(c));
  }
  @Test
  public void testMultiply(){
      assertEquals(new Complex(0,-5),a.ComplexMultiply(b));
      assertEquals(new Complex(17,4),new Complex(3,2.5).ComplexMultiply(c));
  }
  @Test
  public void testDivide(){
      assertEquals(new Complex(0,0.5),a.ComplexDivide(c));
      assertEquals(new Complex(-2,-1),b.ComplexDivide(new Complex(1,0)));
  }
}

Screenshot of passing test

screenshot of git log

(3) Refactoring

RenameYou can rename classes, packages, methods, and variables to increase code readability.

Refactor-> Encapsulate Field...used to encapsulate member variables

Source-> Generate toString()...used to generate a toString method

(4) Complete the learning of Java cryptography in pairs

The key of the Caesar cipher is 3, and the algorithm is to replace the letters in the ordinary alphabet with the letters corresponding to the key

The encryption process of the Caesar cipher can be recorded as the following transformation:

c≡m+k mod n （其中n为基本字符个数）

Likewise, the decryption process can be expressed as:

m≡c+k mod n （其中n为基本字符个数）

The results are as follows:

Refactoring
Set Code and Rename to Caesar, and assign an initial value of 0 to p

3. Experimental experience

Through this experiment, I once again realized the charm of pair programming, and through learning to refactor the code, I also understood the importance of code specification and readability.

4. PSP

step	time consuming	percentage
demand analysis	20min	8%
design	60min	25%
Code	120min	50%
test	10min	4%
analysis Summary	30min	13%