Java로 DSL 개발 #2

[프로젝트 구성]

1. 새 프로젝트 생성
   1. IntelliJ -> File -> New Project
   2. Gradle, Java
   3. Name 셋팅 완료

plugins {
    id 'java'
}

group 'org.example'
version '1.0-SNAPSHOT'

repositories {
    mavenCentral()
}

dependencies {
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.7.0'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.7.0'
}

test {
    useJUnitPlatform()
}

Gradle 업데이트

./gradlew wrapper --gradle-version 8.1.1

 

작업 폴더 구성

• src/main/java -> Project Structure에서 Sources 구성
• src/test/java -> Test 구성

 

 

 

일반적인 도메인 서비스 구현 예)

주식 거래 생성 : Order

거래 : Trade (매수/매도, 금액, 수량, 주식)

주식 : Stock (상장기관, 상장사)

import java.util.ArrayList;
import java.util.List;

public class Order {
    private String customer;
    private List<Trade> trades = new ArrayList<>();

    public void addTrade(Trade trade) {
        trades.add(trade);
    }

    public String getCustomer() {
        return customer;
    }

    public void setCustomer(final String customer) {
        this.customer = customer;
    }

    public double getValue() {
        return trades.stream().mapToDouble(Trade::getValue).sum();
    }
}

public class Trade {
    public enum Type {BUY, SELL}

    private Type type;
    private Stock stock;
    private int quantity;
    private double price;

    public Type getType() {
        return type;
    }

    public void setType(final Type type) {
        this.type = type;
    }

    public Stock getStock() {
        return stock;
    }

    public void setStock(final Stock stock) {
        this.stock = stock;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(final int quantity) {
        this.quantity = quantity;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(final double price) {
        this.price = price;
    }

    public double getValue() {
        return quantity * price;
    }
}

public class Stock {
    private String symbol;
    private String market;

    public String getSymbol() {
        return symbol;
    }

    public void setSymbol(final String symbol) {
        this.symbol = symbol;
    }

    public String getMarket() {
        return market;
    }

    public void setMarket(final String market) {
        this.market = market;
    }

}

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;

public class TradeStockTest {
    @Test
    void 도메인객체를이용한주식거래() {
        Order order = new Order();
        order.setCustomer("BigBank");

        Stock stock1 = new Stock();
        stock1.setSymbol("IBM");
        stock1.setMarket("NYSE");

        Trade trade1 = new Trade();
        trade1.setType(Trade.Type.BUY);
        trade1.setStock(stock1);
        trade1.setPrice(125.00);
        trade1.setQuantity(80);

        order.addTrade(trade1);


        Stock stock2 = new Stock();
        stock2.setSymbol("GOOGLE");
        stock2.setMarket("NASDAQ");

        Trade trade2 = new Trade();
        trade2.setType(Trade.Type.BUY);
        trade2.setStock(stock2);
        trade2.setPrice(375.00);
        trade2.setQuantity(50);

        order.addTrade(trade2);

        Assertions.assertEquals(28750.0, order.getValue());
    }
}

 

#DSL 구현 실습

Live Step by Step 따라하기...

 

NestedFunction DSL Test case

package trading.dsl.nestedfunction;

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import trading.domain.Order;

public class NestedFunctionOrderBuilderTest {

//    @Test
//    void builderTest1() {
//        Order order = order("Customer"
//                , buy(90, 100.0, stock("Apple","NASDAQ"))
//                , sell(50, 100.0, stock("GOOGLE","KOSPI"))
//        );
//
//        Assertions.assertEquals("Customer", order.getCustomer());
//
//        Assertions.assertEquals(9000.0, order.getValue());
//    }
}

 

ChaningMethod DSL Test case

public class ChainingMethodOrderBuilderTest {
    @Test
    void builderTest() {
        ChainingMethodOrderBuilder builder = ChainingMethodOrderBuilder.customer("Customer");
        Assertions.assertEquals("Customer", builder.getCustomer());
    }

    @Test
    void builderTestByTrade() {
        TradeBuilder builder = ChainingMethodOrderBuilder.customer("Customer")
                .buy(100);

        Assertions.assertNotNull(builder);
    }

    @Test
    void builderTestByStockBuilder() {
        StockBuilder builder = ChainingMethodOrderBuilder.customer("Customer")
                .buy(100)
                .price(99.00)
                .stock("Apple")
                ;
        Assertions.assertNotNull(builder);
    }

    @Test
    void builderTestByMarket() {
        ChainingMethodOrderBuilder builder = ChainingMethodOrderBuilder.customer("Customer")
                .buy(100)
                .price(99.00)
                .stock("Apple")
                .market("NASDAQ")
                ;
        Assertions.assertNotNull(builder);
    }

    @Test
    void builderTestForOrder() {
        Order order = ChainingMethodOrderBuilder.customer("Customer")
                .buy(100)
                .price(99.00)
                .stock("Apple")
                .market("NASDAQ")
                .end();
        Assertions.assertEquals(9900.0, order.getValue());
    }

    @Test
    void builderTestForMultifulTrades() {
        Order order = ChainingMethodOrderBuilder.customer("Justin")
                .buy(100)
                .price(100.0)
                .stock("IBM")
                .market("NASDAQ")
                .sell(50)
                .price(100.0)
                .stock("APPLE")
                .market("NASDAQ")
                .end();

        Assertions.assertEquals(14900.0, order.getValue());
    }
}