Moving file parser inside the core-java module.

Adding Test cases for reading files.

core-java/src/main/java/com/baeldung/fileparser/BufferedReaderExample.java

@@ -7,18 +7,8 @@ import java.util.ArrayList;
 
 public class BufferedReaderExample {
 
-    private static final String FILENAME = "src/resources/txt.txt";
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
 
-    public static void main(String[] args) {
-        try {
-            System.out.println(generateArrayListFromFile(FILENAME));
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    private static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
-        
         ArrayList<String> result = new ArrayList<>();
 
         try (BufferedReader br = new BufferedReader(new FileReader(filename))) {

core-java/src/main/java/com/baeldung/fileparser/FileConstants.java

@@ -0,0 +1,8 @@
+package com.baeldung.fileparser;
+
+public class FileConstants {
+
+    protected static final String TEXT_FILENAME = "src/main/resources/sampleTextFile.txt";
+
+    protected static final String NNUMBER_FILENAME = "src/main/resources/sampleNumberFile.txt";
+}

core-java/src/main/java/com/baeldung/fileparser/FileReaderExample.java

@@ -0,0 +1,31 @@
+package com.baeldung.fileparser;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+
+public class FileReaderExample {
+
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
+
+        ArrayList<String> result = new ArrayList<>();
+
+        try (FileReader f = new FileReader(filename)) {
+            StringBuffer sb = new StringBuffer();
+            while (f.ready()) {
+                char c = (char) f.read();
+                if (c == '\n') {
+                    result.add(sb.toString());
+                    sb = new StringBuffer();
+                } else {
+                    sb.append(c);
+                }
+            }
+            if (sb.length() > 0) {
+                result.add(sb.toString());
+            }
+        }
+        
+        return result;
+    }
+}

core-java/src/main/java/com/baeldung/fileparser/FilesReadLinesExample.java

@@ -0,0 +1,18 @@
+package com.baeldung.fileparser;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+public class FilesReadLinesExample {
+
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
+        
+        List<String> result = Files.readAllLines(Paths.get(filename));
+        
+        return (ArrayList<String>) result;
+    }
+
+}

core-java/src/main/java/com/baeldung/fileparser/ScannerIntExample.java

@@ -7,17 +7,7 @@ import java.util.Scanner;
 
 public class ScannerIntExample {
 
-    private static final String FILENAME = "src/resources/num.txt";
+    protected static ArrayList<Integer> generateArrayListFromFile(String filename) throws IOException {
-
-    public static void main(String[] args) {
-        try {
-            System.out.println(generateArrayListFromFile(FILENAME));
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    private static ArrayList<Integer> generateArrayListFromFile(String filename) throws IOException {
         
         ArrayList<Integer> result = new ArrayList<>();
 

core-java/src/main/java/com/baeldung/fileparser/ScannerStringExample.java

@@ -7,17 +7,7 @@ import java.util.Scanner;
 
 public class ScannerStringExample {
 
-    private static final String FILENAME = "src/resources/txt.txt";
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
-
-    public static void main(String[] args) {
-        try {
-            System.out.println(generateArrayListFromFile(FILENAME));
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    private static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
         
         ArrayList<String> result = new ArrayList<>();
 

core-java/src/test/java/com/baeldung/fileparser/BufferedReaderUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.fileparser;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class BufferedReaderUnitTest {
+
+    protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
+    
+    @Test
+    public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
+        List<String> lines = BufferedReaderExample.generateArrayListFromFile(TEXT_FILENAME);
+        assertTrue("File does not has 2 lines", lines.size() == 2);
+    }
+}

core-java/src/test/java/com/baeldung/fileparser/FileReaderUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.fileparser;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class FileReaderUnitTest {
+
+    protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
+    
+    @Test
+    public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
+        List<String> lines = FileReaderExample.generateArrayListFromFile(TEXT_FILENAME);
+        assertTrue("File does not has 2 lines", lines.size() == 2);
+    }
+}

core-java/src/test/java/com/baeldung/fileparser/FilesReadAllLinesUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.fileparser;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class FilesReadAllLinesUnitTest {
+
+    protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
+
+    @Test
+    public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
+        List<String> lines = FilesReadLinesExample.generateArrayListFromFile(TEXT_FILENAME);
+        assertTrue("File does not has 2 lines", lines.size() == 2);
+    }
+}

core-java/src/test/java/com/baeldung/fileparser/ScannerIntUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.fileparser;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class ScannerIntUnitTest {
+
+    protected static final String NUMBER_FILENAME = "src/test/resources/sampleNumberFile.txt";
+    
+    @Test
+    public void whenParsingExistingTextFile_thenGetIntArrayList() throws IOException {
+        List<Integer> numbers = ScannerIntExample.generateArrayListFromFile(NUMBER_FILENAME);
+        assertTrue("File does not has 2 lines", numbers.size() == 2);
+    }
+}

core-java/src/test/java/com/baeldung/fileparser/ScannerStringUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.fileparser;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class ScannerStringUnitTest {
+
+    protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
+    
+    @Test
+    public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
+        List<String> lines = ScannerStringExample.generateArrayListFromFile(TEXT_FILENAME);
+        assertTrue("File does not has 2 lines", lines.size() == 2);
+    }
+}

core-java/src/test/resources/sampleNumberFile.txt

@@ -0,0 +1,2 @@
+111
+222

core-java/src/test/resources/sampleTextFile.txt

@@ -0,0 +1,2 @@
+Hello 
+World

file-parser/src/com/baeldung/fileparser/FileReaderExample.java

@@ -1,37 +0,0 @@
-package com.baeldung.fileparser;
-
-import java.io.FileReader;
-import java.io.IOException;
-import java.util.ArrayList;
-
-public class FileReaderExample {
-
-    private static final String FILENAME = "src/resources/txt.txt";
-
-    public static void main(String[] args) {
-        try {
-            System.out.println(generateArrayListFromFile(FILENAME));
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    private static ArrayList<Character> generateArrayListFromFile(String filename) throws IOException {
-
-        ArrayList<Character> result = new ArrayList<>();
-
-        try (FileReader f = new FileReader(filename)) {
-
-            while (f.ready()) {
-                char c = (char) f.read();
-
-                if (c != ' ' && c != '\t' && c != '\n') {
-                    result.add(c);
-                }
-            }
-            return result;
-        }
-
-    }
-
-}

file-parser/src/com/baeldung/fileparser/FilesReadLineExample.java

@@ -1,28 +0,0 @@
-package com.baeldung.fileparser;
-
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Paths;
-import java.util.ArrayList;
-import java.util.List;
-
-public class FilesReadLineExample {
-
-    private static final String FILENAME = "src/resources/txt.txt";
-
-    public static void main(String[] args) {
-        try {
-            System.out.println(generateArrayListFromFile(FILENAME));
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    private static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
-        
-        List<String> result = Files.readAllLines(Paths.get(filename));
-        
-        return (ArrayList<String>) result;
-    }
-
-}