Examples for Reading a file into an arraylist.

1. Using FileReader
2. Using BufferedReader
3. Using Scanner(String and int)
4. Using Files.readAllLines

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

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+package com.baeldung.fileparser;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+
+public class BufferedReaderExample {
+
+    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 {
+        
+        ArrayList<String> result = new ArrayList<>();
+
+        try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
+
+            while (br.ready()) {
+                result.add(br.readLine());
+            }
+            return result;
+        }
+
+    }
+
+}

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

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+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

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+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;
+    }
+
+}

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

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+package com.baeldung.fileparser;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class ScannerIntExample {
+
+    private static final String FILENAME = "src/resources/num.txt";
+
+    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<>();
+
+        try (Scanner s = new Scanner(new FileReader(filename))) {
+
+            while (s.hasNext()) {
+                result.add(s.nextInt());
+            }
+            return result;
+        }
+
+    }
+
+}

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

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+package com.baeldung.fileparser;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class ScannerStringExample {
+
+    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 {
+        
+        ArrayList<String> result = new ArrayList<>();
+
+        try (Scanner s = new Scanner(new FileReader(filename))) {
+
+            while (s.hasNext()) {
+                result.add(s.nextLine());
+            }
+            return result;
+        }
+
+    }
+
+}

file-parser/src/resources/num.txt

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+111
+222

file-parser/src/resources/txt.txt

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+Hello 
+World