added read from file class and android tests for him

app/src/androidTest/java/com/googleresearch/capturesync/ReadFromFileTests.java

@@ -0,0 +1,52 @@
+package com.googleresearch.capturesync;
+
+import android.content.Context;
+
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.platform.app.InstrumentationRegistry;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ReadFromFileTests {
+    Context unitTestContext;
+
+    @Before
+    public void initContext() {
+        unitTestContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        unitTestContext = ApplicationProvider.getApplicationContext();
+    }
+
+    @Test
+    public void readFromFile_CoordinatesArray_isCorrect() {
+        double[][] correctArray = { { (double)1.8405248, (double)-1.7660676, (double)0.49335796 }, { (double)1.8783984, (double)-1.8546431, (double)0.5410055 }, { (double)1.8924483, (double)-1.896182, (double)0.5593314 } };
+        String namefile = "ForUnitTestFile1.csv";
+
+        Assert.assertArrayEquals(correctArray, ReadFromFile.ReadFromCSV(namefile, unitTestContext).first);
+    }
+
+    @Test
+    public void readFromFile_TimesArray_isCorrect() {
+        double[] correctArray = { (double)691166767933511L / 1e9, (double)691166769907511L / 1e9, (double)691166771907511L / 1e9 };
+        String namefile = "ForUnitTestFile1.csv";
+
+        Assert.assertArrayEquals(correctArray, ReadFromFile.ReadFromCSV(namefile, unitTestContext).second, 0.1);
+    }
+
+    @Test
+    public void readFromFile_IncorrectCSV() {
+        double[] correctArray = new double[0];
+        String namefile = "ForUnitTestFile2.csv";
+
+        Assert.assertArrayEquals(correctArray, ReadFromFile.ReadFromCSV(namefile, unitTestContext).second, 0.1);
+    }
+
+    @Test
+    public void readFromFile_EmptyFile() {
+        double[] correctArray = new double[0];
+        String namefile = "ForUnitTestFile3.csv";
+
+        Assert.assertArrayEquals(correctArray, ReadFromFile.ReadFromCSV(namefile, unitTestContext).second, 0.1);
+    }
+}

app/src/main/java/com/googleresearch/capturesync/ReadFromFile.java

@@ -0,0 +1,63 @@
+package com.googleresearch.capturesync;
+
+import android.content.Context;
+import android.util.Pair;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public class ReadFromFile {
+    private static int CountOfRows(String namefile, Context context) {
+        int counter = 0;
+
+        try {
+            InputStream inputStream = context.getAssets().open(namefile);
+            for (int symbol = 0; symbol != -1; symbol = inputStream.read()) {
+                counter += symbol == '\n' ? 1 : 0;
+            }
+        } catch (IOException exception) {
+            System.out.println("Error Reading The File.");
+            exception.printStackTrace();
+        }
+
+        return counter;
+    }
+
+    public static Pair<double[][], double[]> ReadFromCSV(String namefile, Context context) {
+        double[][] coordinatesArray = new double[0][0];
+        double[] timeArray = new double[0];
+
+        try {
+            InputStream inputStream = context.getAssets().open(namefile);
+            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
+            int countOfRows = CountOfRows(namefile, context);
+            coordinatesArray = new double[countOfRows][3];
+            timeArray = new double[countOfRows];
+            int index = 0;
+
+            while(bufferedReader.ready()) {
+                String[] line = bufferedReader.readLine().split(",");
+                double[] tempCoordinatesArray = { Double.parseDouble(line[0]), Double.parseDouble(line[1]), Double.parseDouble(line[2])};
+                coordinatesArray[index] = tempCoordinatesArray;
+                timeArray[index] = Double.parseDouble(line[3]) / 1e9;
+
+                index++;
+            }
+        } catch (FileNotFoundException exception) {
+            System.out.println("File Not Found.");
+            exception.printStackTrace();
+        } catch (IOException exception) {
+            System.out.println("Error Reading The File.");
+            exception.printStackTrace();
+        } catch (ArrayIndexOutOfBoundsException exception) {
+            System.out.println("CSV incorrect");
+            exception.printStackTrace();
+            return new Pair<>(new double[0][0], new double[0]);
+        }
+
+        return new Pair<>(coordinatesArray, timeArray);
+    }
+}