Added support for reading and writing stock data to a file

src/main/java/millions/controller/fileIO/CSVStockFileParser.java

@@ -0,0 +1,42 @@
+package millions.controller.fileIO;
+
+import millions.model.Stock;
+
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.List;
+
+public class CSVStockFileParser {
+  private List<String> lines;
+
+  public CSVStockFileParser(List<String> lines) {
+    if (verifyCSV(lines)) {
+      this.lines = lines;
+    }
+    else {
+      // throw file format error
+    }
+  }
+
+  // returns true if all entries have exactly 3 data points
+  public boolean verifyCSV(List<String> lines) {
+    return lines.stream()
+          .filter(l -> !(l.startsWith("#") || l.isBlank()))
+          .noneMatch(l -> l.split(",").length != 3);
+
+  }
+
+  public List<Stock> parse() {
+    List<Stock> stocks = new ArrayList<>();
+    lines.stream()
+        .filter(l -> !((l.startsWith("#") || l.isBlank())))
+        .forEach(l -> {
+      String[] split = l.split(",");
+      String symbol = split[0];
+      String company = split[1];
+      BigDecimal price = new BigDecimal(split[2]);
+      stocks.add(new Stock(symbol, company, price));
+    });
+    return stocks;
+  }
+}

src/main/java/millions/controller/fileIO/CSVStockFileWriter.java

@@ -0,0 +1,43 @@
+package millions.controller.fileIO;
+
+import millions.model.Stock;
+
+import java.io.BufferedWriter;
+import java.io.*;
+import java.nio.file.Path;
+import java.util.List;
+
+//TODO: Validation of data before writing
+public class CSVStockFileWriter implements StockFileWriter {
+  private final List<Stock> stocks;
+  private String finalString;
+
+  public CSVStockFileWriter(List<Stock> stocks) {
+    this.stocks = stocks;
+  }
+
+  @Override
+  public void formatString() {
+    StringBuilder builder = new StringBuilder();
+    stocks.forEach(stock -> {
+      builder.append(stock.getSymbol());
+      builder.append(",");
+      builder.append(stock.getCompany());
+      builder.append(",");
+      builder.append(stock.getSalesPrice().toString());
+      builder.append("\n");
+    });
+    this.finalString = builder.toString();
+  }
+
+  @Override
+  public boolean write(Path path){
+    try (FileWriter fw = new FileWriter(path.toString()); BufferedWriter writer = new BufferedWriter(fw);) {
+      this.formatString();
+      writer.write(finalString);
+    } catch (IOException e) {
+      e.printStackTrace();
+    }
+    return false;
+  }
+}

src/main/java/millions/controller/fileIO/StockFileReader.java

@@ -0,0 +1,26 @@
+package millions.controller.fileIO;
+
+import java.io.*;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+
+public class StockFileReader {
+  private final Path filePath;
+
+  public StockFileReader(Path path) {
+    this.filePath = path;
+  }
+
+  public List<String> readFile() {
+    File file = new File(filePath.toString());
+    List<String> lines = new ArrayList<>();
+    try (Reader reader = new FileReader(file); BufferedReader bufferedReader = new BufferedReader(reader)) {
+      lines = bufferedReader.readAllLines();
+    } catch (IOException e) {
+      e.printStackTrace();
+    }
+    return lines;
+  }
+}

src/main/java/millions/controller/fileIO/StockFileWriter.java

@@ -0,0 +1,8 @@
+package millions.controller.fileIO;
+
+import java.nio.file.Path;
+
+public interface StockFileWriter {
+  public void formatString();
+  public boolean write(Path path);
+}

src/main/java/millions/model/Stock.java

@@ -73,4 +73,9 @@ public BigDecimal getLatestPriceChange() {
 
     return currentPrice.subtract(lastPrice);
   }
+
+  @Override
+  public String toString() {
+    return "Stock [symbol: " + symbol + ", company: " + company + ", prices: " + prices + "]";
+  }
 }

src/test/java/millions/CSVStockFileParserTest.java

@@ -0,0 +1,41 @@
+package millions;
+
+import millions.controller.fileIO.CSVStockFileParser;
+import millions.controller.fileIO.StockFileReader;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CSVStockFileParserTest {
+  @TempDir
+  static Path tempDir;
+
+  static Path sharedFile;
+
+  @BeforeAll
+  public static void setUpTestFile() throws Exception {
+    sharedFile = Files.createFile(tempDir.resolve("file.csv"));
+    String string = "# Top 500 US Stocks by Market Cap\n";
+    string += "# Ticker,Name,Price\n";
+    string += "\n";
+    string += "NVDA,Nvidia,191.27\n";
+    string += "AAPL,Apple Inc.,276.43\n";
+    string += "MSFT,Microsoft,404.68\n";
+    Files.writeString(sharedFile, string);
+  }
+
+  @Test
+  public void parseStockFileTest(){
+    StockFileReader stockFileReader = new StockFileReader(sharedFile);
+
+    CSVStockFileParser parser = new CSVStockFileParser(stockFileReader.readFile());
+    assertEquals(3, parser.parse().size());
+  }
+}

src/test/java/millions/CSVStockFileWriterTest.java

@@ -0,0 +1,43 @@
+package millions;
+
+import millions.controller.fileIO.CSVStockFileWriter;
+import millions.controller.fileIO.StockFileReader;
+import millions.model.Stock;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.math.BigDecimal;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CSVStockFileWriterTest {
+  @TempDir
+  static Path tempDir;
+
+  List<Stock> stocks;
+
+  @BeforeEach
+  void setup() {
+    Stock s1 = new Stock("PEAR", "Pear Inc.", BigDecimal.valueOf(300));
+    Stock s2 = new Stock("DOGL", "DOOGLE Inc.", BigDecimal.valueOf(200.00));
+    Stock s3 = new Stock("MSFT", "EpsteinSoft Inc.", BigDecimal.valueOf(0.02));
+
+    this.stocks = List.of(s1, s2, s3);
+  }
+
+  @Test
+  public void testWrite() {
+    for(Stock stock : this.stocks) {
+      System.out.println(stock.toString());
+    }
+    CSVStockFileWriter csvStockFileWriter = new CSVStockFileWriter(stocks);
+    csvStockFileWriter.write(tempDir.resolve("stocks.csv"));
+
+    StockFileReader stockFileReader = new StockFileReader(tempDir.resolve("stocks.csv"));
+    assertEquals(3, stockFileReader.readFile().size());
+  }
+}

src/test/java/millions/StockFileReaderTest.java

@@ -0,0 +1,35 @@
+package millions;
+
+import millions.controller.fileIO.StockFileReader;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class StockFileReaderTest {
+  @TempDir
+  static Path tempDir;
+
+  static Path sharedFile;
+  @BeforeAll
+  public static void setUpTestFile() throws Exception {
+    sharedFile = Files.createFile(tempDir.resolve("file.csv"));
+    String string = "# Top 500 US Stocks by Market Cap\n";
+    string += "# Ticker,Name,Price\n";
+    string += "\n";
+    string += "NVDA,Nvidia,191.27\n";
+    string += "AAPL,Apple Inc.,276.43\n";
+    string += "MSFT,Microsoft,404.68\n";
+    Files.writeString(sharedFile, string);
+  }
+
+  @Test
+  public void testReadStockFile() {
+    StockFileReader stockFileReader = new StockFileReader(sharedFile);
+    assertEquals(6, stockFileReader.readFile().size());
+  }
+}