Improve SRP by decomposing Utils.java and CSVImporter.java

xchart/src/main/java/org/knowm/xchart/CSVImporter.java

@@ -6,6 +6,8 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+
+import org.knowm.xchart.internal.FileUtils;
 import org.knowm.xchart.style.Styler.ChartTheme;
 
 /**
@@ -39,7 +41,7 @@ public static XYChart getChartFromCSVDir(
     }
 
     // 2. get all the csv files in the dir
-    File[] csvFiles = getAllFiles(path2Directory, ".*.csv");
+    File[] csvFiles = FileUtils.getAllFiles(path2Directory, ".*.csv");
 
     // 3. create a series for each file, naming the series the file name
     for (File csvFile : csvFiles) {
@@ -53,14 +55,14 @@ public static XYChart getChartFromCSVDir(
       if (xAndYData[2] == null || xAndYData[2].trim().equalsIgnoreCase("")) {
         chart.addSeries(
             csvFile.getName().substring(0, csvFile.getName().indexOf(".csv")),
-            getAxisData(xAndYData[0]),
-            getAxisData(xAndYData[1]));
+            DataConverter.getAxisData(xAndYData[0]),
+            DataConverter.getAxisData(xAndYData[1]));
       } else {
         chart.addSeries(
             csvFile.getName().substring(0, csvFile.getName().indexOf(".csv")),
-            getAxisData(xAndYData[0]),
-            getAxisData(xAndYData[1]),
-            getAxisData(xAndYData[2]));
+            DataConverter.getAxisData(xAndYData[0]),
+            DataConverter.getAxisData(xAndYData[1]),
+            DataConverter.getAxisData(xAndYData[2]));
       }
     }
 
@@ -81,8 +83,8 @@ public static SeriesData getSeriesDataFromCSVFile(
       xAndYData = getSeriesDataFromCSVColumns(csvFile);
     }
     return new SeriesData(
-        getAxisData(xAndYData[0]),
-        getAxisData(xAndYData[1]),
+        DataConverter.getAxisData(xAndYData[0]),
+        DataConverter.getAxisData(xAndYData[1]),
         csvFile.getName().substring(0, csvFile.getName().indexOf(".csv")));
   }
 
@@ -168,76 +170,7 @@ private static String[] getSeriesDataFromCSVColumns(File csvFile) {
     return xAndYData;
   }
 
-  /**
-   * @param stringData
-   * @return
-   */
-  private static List<Number> getAxisData(String stringData) {
-
-    List<Number> axisData = new ArrayList<Number>();
-    String[] stringDataArray = stringData.split(",");
-    for (String dataPoint : stringDataArray) {
-      try {
-        Double value = Double.parseDouble(dataPoint);
-        axisData.add(value);
-      } catch (NumberFormatException e) {
-        System.out.println("Error parsing >" + dataPoint + "< !");
-        throw (e);
-      }
-    }
-    return axisData;
-  }
-
-  /**
-   * This method returns the files found in the given directory matching the given regular
-   * expression.
-   *
-   * @param dirName - ex. "./path/to/directory/" *make sure you have the '/' on the end
-   * @param regex - ex. ".*.csv"
-   * @return File[] - an array of files
-   */
-  private static File[] getAllFiles(String dirName, String regex) {
-
-    File[] allFiles = getAllFiles(dirName);
 
-    List<File> matchingFiles = new ArrayList<File>();
-
-    for (File allFile : allFiles) {
-
-      if (allFile.getName().matches(regex)) {
-        matchingFiles.add(allFile);
-      }
-    }
-
-    return matchingFiles.toArray(new File[matchingFiles.size()]);
-  }
-
-  /**
-   * This method returns the Files found in the given directory
-   *
-   * @param dirName - ex. "./path/to/directory/" *make sure you have the '/' on the end
-   * @return File[] - an array of files
-   */
-  private static File[] getAllFiles(String dirName) {
-
-    File dir = new File(dirName);
-
-    File[] files = dir.listFiles(); // returns files and folders
-
-    if (files != null) {
-      List<File> filteredFiles = new ArrayList<File>();
-      for (File file : files) {
-
-        if (file.isFile()) {
-          filteredFiles.add(file);
-        }
-      }
-      return filteredFiles.toArray(new File[filteredFiles.size()]);
-    } else {
-      System.out.println(dirName + " does not denote a valid directory!");
-      return new File[0];
-    }
-  }
 
   public enum DataOrientation {
     Rows,

xchart/src/main/java/org/knowm/xchart/DataConverter.java

@@ -0,0 +1,27 @@
+package org.knowm.xchart;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class DataConverter {
+    /**
+     * @param stringData
+     * @return
+     */
+    public static List<Number> getAxisData(String stringData) {
+
+        List<Number> axisData = new ArrayList<Number>();
+        String[] stringDataArray = stringData.split(",");
+        for (String dataPoint : stringDataArray) {
+            try {
+                Double value = Double.parseDouble(dataPoint);
+                axisData.add(value);
+            } catch (NumberFormatException e) {
+                System.out.println("Error parsing >" + dataPoint + "< !");
+                throw (e);
+            }
+        }
+        return axisData;
+    }
+
+}

xchart/src/main/java/org/knowm/xchart/GifEncoder.java

@@ -3,7 +3,7 @@
 import com.madgag.gif.fmsware.AnimatedGifEncoder;
 import java.awt.image.BufferedImage;
 import java.util.List;
-import org.knowm.xchart.internal.Utils;
+import org.knowm.xchart.internal.FileUtils;
 
 /** A helper class with static methods for saving Charts as a GIF file */
 public class GifEncoder {
@@ -31,7 +31,7 @@ public static void saveGif(String filePath, List<BufferedImage> images) {
   public static void saveGif(String filePath, List<BufferedImage> images, int repeat, int delay) {
     AnimatedGifEncoder gif = new AnimatedGifEncoder();
     gif.setRepeat(repeat);
-    gif.start(Utils.addFileExtension(filePath, GIF_FILE_EXTENSION));
+    gif.start(FileUtils.addFileExtension(filePath, GIF_FILE_EXTENSION));
     gif.setDelay(delay);
     for (BufferedImage image : images) {
       gif.addFrame(image);

xchart/src/main/java/org/knowm/xchart/internal/FileUtils.java

@@ -0,0 +1,78 @@
+package org.knowm.xchart.internal;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+public class FileUtils {
+    /**
+     * Only adds the extension of the fileExtension to the filename if the filename doesn't already
+     * have it.
+     *
+     * @param fileName File name
+     * @param fileExtension File extension
+     * @return filename (if extension already exists), otherwise;: filename + fileExtension
+     */
+    public static String addFileExtension(String fileName, String fileExtension) {
+        String fileNameWithFileExtension = fileName;
+        if (fileName.length() <= fileExtension.length()
+                || !fileName
+                .substring(fileName.length() - fileExtension.length())
+                .equalsIgnoreCase(fileExtension)) {
+            fileNameWithFileExtension = fileName + fileExtension;
+        }
+        return fileNameWithFileExtension;
+    }
+
+    /**
+     * This method returns the files found in the given directory matching the given regular
+     * expression.
+     *
+     * @param dirName - ex. "./path/to/directory/" *make sure you have the '/' on the end
+     * @param regex - ex. ".*.csv"
+     * @return File[] - an array of files
+     */
+    public static File[] getAllFiles(String dirName, String regex) {
+
+        File[] allFiles = getAllFiles(dirName);
+
+        List<File> matchingFiles = new ArrayList<File>();
+
+        for (File allFile : allFiles) {
+
+            if (allFile.getName().matches(regex)) {
+                matchingFiles.add(allFile);
+            }
+        }
+
+        return matchingFiles.toArray(new File[matchingFiles.size()]);
+    }
+
+    /**
+     * This method returns the Files found in the given directory
+     *
+     * @param dirName - ex. "./path/to/directory/" *make sure you have the '/' on the end
+     * @return File[] - an array of files
+     */
+    public static File[] getAllFiles(String dirName) {
+
+        File dir = new File(dirName);
+
+        File[] files = dir.listFiles(); // returns files and folders
+
+        if (files != null) {
+            List<File> filteredFiles = new ArrayList<File>();
+            for (File file : files) {
+
+                if (file.isFile()) {
+                    filteredFiles.add(file);
+                }
+            }
+            return filteredFiles.toArray(new File[filteredFiles.size()]);
+        } else {
+            System.out.println(dirName + " does not denote a valid directory!");
+            return new File[0];
+        }
+    }
+
+}

xchart/src/main/java/org/knowm/xchart/internal/Utils.java

@@ -179,22 +179,4 @@ public static long[] getLongArrayFromNumberList(List<?> data) {
     return longs;
   }
 
-  /**
-   * Only adds the extension of the fileExtension to the filename if the filename doesn't already
-   * have it.
-   *
-   * @param fileName File name
-   * @param fileExtension File extension
-   * @return filename (if extension already exists), otherwise;: filename + fileExtension
-   */
-  public static String addFileExtension(String fileName, String fileExtension) {
-    String fileNameWithFileExtension = fileName;
-    if (fileName.length() <= fileExtension.length()
-        || !fileName
-            .substring(fileName.length() - fileExtension.length())
-            .equalsIgnoreCase(fileExtension)) {
-      fileNameWithFileExtension = fileName + fileExtension;
-    }
-    return fileNameWithFileExtension;
   }
-}

xchart/src/test/java/org/knowm/xchart/internal/UtilsTest.java

@@ -8,9 +8,9 @@ public class UtilsTest {
 
   @Test
   void addFileExtension() {
-    assertEquals(Utils.addFileExtension("yourchart.png", ".png"), "yourchart.png");
-    assertEquals(Utils.addFileExtension("yourchart.png", ".pn"), "yourchart.png.pn");
-    assertEquals(Utils.addFileExtension("a", ".png"), "a.png");
-    assertEquals(Utils.addFileExtension("a.PNG", ".png"), "a.PNG");
+    assertEquals(FileUtils.addFileExtension("yourchart.png", ".png"), "yourchart.png");
+    assertEquals(FileUtils.addFileExtension("yourchart.png", ".pn"), "yourchart.png.pn");
+    assertEquals(FileUtils.addFileExtension("a", ".png"), "a.png");
+    assertEquals(FileUtils.addFileExtension("a.PNG", ".png"), "a.PNG");
   }
 }