我在Intellij IDEA上写了一个名为Sales Taxes的小项目。为了运行程序，我包含了一个main方法。现在我需要为项目编写JUnit测试。我没有太多编写测试类的经验。如何将main方法转换为Junit测试类？
这是我构建的项目：
基本销售税适用于所有商品的10％税率，但免税的书籍，食品和医疗产品除外。 进口税是适用于所有进口商品的额外销售税，税率为5％，不含豁免。 当我购买物品时，我会收到一张收据，上面列出了所有物品的名称及其价格（包括税金），完成 与项目的总成本，以及支付的销售税总额。销售税的四舍五入规则是 税率为n％，货架价格为p包含（np / 100四舍五入至最接近的0.05）营业税金额。 写一个打印出这些购物篮的收据细节的应用程序......
/*
Definition of Product.java class
Fundamental object for the project.
It keeps all features of the product.
At description of the product, description of the input line for output line.
typeOfProduct: 0:other 1:food 2:book 3: medical products
*/
public class Product{
private int typeOfProduct=0;
private boolean imported=false;
private double price=0;
private double priceWithTaxes=0;
private double taxes=0;
private int quantity=0;
private String description="";
public Product(int quantity, int typeOfProduct, boolean imported, double price, String description)
{
this.quantity=quantity;
this.typeOfProduct = typeOfProduct;
this.imported = imported;
this.price = price;
this.description = description;
}
public void setTypeOfProduct(int typeOfProduct)
{
this.typeOfProduct = typeOfProduct;
}
public int getTypeOfProduct()
{
return typeOfProduct;
}
public void setImported(boolean imported)
{
this.imported = imported;
}
public boolean getImported()
{
return imported;
}
public void setPrice(double price)
{
this.price = price;
}
public double getPrice()
{
return price;
}
public void setTaxes(double taxes)
{
this.taxes = taxes;
}
public double getTaxes()
{
return taxes;
}
public void setPriceWithTaxes(double priceWithTaxes)
{
this.priceWithTaxes = priceWithTaxes;
}
public double getPriceWithTaxes()
{
return priceWithTaxes;
}
public void setQuantity(int quantity)
{
this.quantity = quantity;
}
public int getQuantity()
{
return quantity;
}
public void setDescription(String description)
{
this.description = description;
}
public String getDescription()
{
return description;
}
}
/*
Definition of TaxCalculator.java class
At constructor a Product object is taken.
taxCalculate method; adds necessary taxes to price of product.
Tax rules:
1. if the product is imported, tax %5 of price
2. if the product is not food, book or medical goods, tax %10 of price
typeOfProduct: 0:food 1:book 2: medical products 3:other
*/
public class TaxCalculator {
private Product product=null;
public TaxCalculator(Product product)
{
this.product=product;
}
public void taxCalculate()
{
double price=product.getPrice();
double tax=0;
//check impoted or not
if(product.getImported())
{
tax+= price*5/100;
}
//check type of product
if(product.getTypeOfProduct()==3)
{
tax+= price/10;
}
product.setTaxes(Util.roundDouble(tax));
product.setPriceWithTaxes(Util.roundDouble(tax)+price);
}
}
import java.text.DecimalFormat;
/*
Definition of Util.java class
It rounds and formats the price and taxes.
Round rules for sales taxes: rounded up to the nearest 0.05
Format: 0.00
*/
public class Util {
public static String round(double value)
{
double rounded = (double) Math.round(value * 100)/ 100;
DecimalFormat df=new DecimalFormat("0.00");
rounded = Double.valueOf(df.format(rounded));
return df.format(rounded).toString();
}
public static double roundDouble(double value)
{
double rounded = (double) Math.round(value * 20)/ 20;
if(rounded<value)
{
rounded = (double) Math.round((value+0.05) * 20)/ 20;
}
return rounded;
}
public static String roundTax(double value)
{
double rounded = (double) Math.round(value * 20)/ 20;
if(rounded<value)
{
rounded = (double) Math.round((value+0.05) * 20)/ 20;
}
DecimalFormat df=new DecimalFormat("0.00");
rounded = Double.valueOf(df.format(rounded));
return df.format(rounded).toString();
}
}
import java.util.ArrayList;
import java.util.StringTokenizer;
/*
Definition of SalesManager.java class
This class asks to taxes to TaxCalculator Class and creates Product objects.
*/
public class SalesManager {
private String [][] arTypeOfProduct = new String [][]{
{"CHOCOLATE", "CHOCOLATES", "BREAD", "BREADS", "WATER", "COLA", "EGG", "EGGS"},
{"BOOK", "BOOKS"},
{"PILL", "PILLS", "SYRUP", "SYRUPS"}
};
/*
* It takes all inputs as ArrayList, and returns output as ArrayList
* Difference between output and input arrayLists are Total price and Sales Takes.
*/
public ArrayList<String> inputs(ArrayList<String> items)
{
Product product=null;
double salesTaxes=0;
double total=0;
TaxCalculator tax=null;
ArrayList<String> output=new ArrayList<String>();
for(int i=0; i<items.size(); i++)
{
product= parse(items.get(i));
tax=new TaxCalculator(product);
tax.taxCalculate();
salesTaxes+=product.getTaxes();
total+=product.getPriceWithTaxes();
output.add(""+product.getDescription()+" "+Util.round(product.getPriceWithTaxes()));
}
output.add("Sales Taxes: "+Util.round(salesTaxes));
output.add("Total: "+Util.round(total));
return output;
}
/*
* The method takes all line and create product object.
* To create the object, it analyses all line.
* "1 chocolate bar at 0.85"
* First word is quantity
* Last word is price
* between those words, to analyse it checks all words
*/
public Product parse(String line)
{
Product product=null;
String productName="";
int typeOfProduct=0;
boolean imported=false;
double price=0;
int quantity=0;
String description="";
ArrayList<String> wordsOfInput = new ArrayList<String>();
StringTokenizer st = new StringTokenizer(line, " ");
String tmpWord="";
while (st.hasMoreTokens())
{
tmpWord=st.nextToken();
wordsOfInput.add(tmpWord);
}
quantity=Integer.parseInt(wordsOfInput.get(0));
imported = searchImported(wordsOfInput);
typeOfProduct = searchTypeOfProduct(wordsOfInput);
price=Double.parseDouble(wordsOfInput.get(wordsOfInput.size()-1));
description=wordsOfInput.get(0);
for(int i=1; i<wordsOfInput.size()-2; i++)
{
description=description.concat(" ");
description=description.concat(wordsOfInput.get(i));
}
description=description.concat(":");
product=new Product(quantity, typeOfProduct, imported, price, description);
return product;
}
/*
* It checks all line to find "imported" word, and returns boolean as imported or not.
*/
public boolean searchImported(ArrayList<String> wordsOfInput)
{
boolean result =false;
for(int i=0; i<wordsOfInput.size(); i++)
{
if(wordsOfInput.get(i).equalsIgnoreCase("imported"))
{
return true;
}
}
return result;
}
//typeOfProduct: 0:food 1:book 2: medical goods 3:other
/*
* It checks all 2D array to find the typeOf product
* i=0 : Food
* i=1 : Book
* i=2 : Medical goods
*/
public int searchTypeOfProduct (ArrayList<String> line)
{
int result=3;
for(int k=1; k<line.size()-2; k++)
{
for(int i=0; i<arTypeOfProduct.length; i++)
{
for(int j=0; j<arTypeOfProduct[i].length; j++)
{
if(line.get(k).equalsIgnoreCase(arTypeOfProduct[i][j]))
{
return i;
}
}
}
}
return result;
}
}
import java.io.IOException;
import java.util.ArrayList;
public class SalesTaxes {
public static void main(String args[]) throws IOException
{
ArrayList<String> input = new ArrayList<String>();
ArrayList<String> output = new ArrayList<String>();
SalesManager sal = new SalesManager();
/*
* First input set
*/
System.out.println("First input Set");
System.out.println();
input = new ArrayList<String>();
input.add("1 book at 12.49");
input.add("1 music CD at 14.99");
input.add("1 chocolate bar at 0.85");
sal=new SalesManager();
output= sal.inputs(input);
for(int i=0; i<output.size(); i++)
{
System.out.println(output.get(i));
}
/*
* Second input set
*/
System.out.println();
System.out.println("Second input Set");
System.out.println();
input = new ArrayList<String>();
input.add("1 imported box of chocolates at 10.00");
input.add("1 imported bottle of perfume at 47.50");
sal=new SalesManager();
output= sal.inputs(input);
for(int i=0; i<output.size(); i++)
{
System.out.println(output.get(i));
}
/*
* Third input set
*/
System.out.println();
System.out.println("Third input Set");
System.out.println();
input = new ArrayList<String>();
input.add("1 imported bottle of perfume at 27.99");
input.add("1 bottle of perfume at 18.99");
input.add("1 packet of headache pills at 9.75");
input.add("1 box of imported chocolates at 11.25");
output= sal.inputs(input);
for(int i=0; i<output.size(); i++)
{
System.out.println(output.get(i));
}
}
}
答案 0 :(得分：1)
我认为你可以从搜索如何编写单元测试开始，也许你不会有这样的问题。重点是测试一些功能。例如，在您的情况下，您应该测试 taxCalculate 方法并检查您的产品中是否正确设置了税，在这种情况下，您可能需要获取产品的getter。
另外，请检查：how to write a unit test。
答案 1 :(得分：0)
“单元测试”适用于一个班级。
所以我不会从主方法开始：那不会给你“单元测试”。这会给你一个“集成测试”（一次测试一堆你的类）。
因此，对于单元测试，我首先编写一个UtilTest类来测试你的Util类。这有公共方法，可以很容易地给出不同的输入和结果断言。例如如果你给roundTax零或21.0等，你会得到什么？