Added a file util example

Author: botenbreuk

src/main/java/nl/rdb/java_examples/files/FileUtil.java

@@ -0,0 +1,40 @@
+package nl.rdb.java_examples.files;
+
+import static lombok.AccessLevel.PRIVATE;
+
+import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.Charset;
+import java.util.function.Consumer;
+
+import lombok.NoArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@NoArgsConstructor(access = PRIVATE)
+public class FileUtil {
+
+    public static void readFile(String fileName, Consumer<String> stringSupplier) {
+        readFile(fileName, stringSupplier, Charset.defaultCharset());
+    }
+
+    public static void readFile(String fileName, Consumer<String> stringSupplier, Charset charset) {
+        try (final BufferedReader file = new BufferedReader(new InputStreamReader(new FileInputStream(fileName), charset))) {
+            for (String line = file.readLine(); line != null; line = file.readLine()) {
+                stringSupplier.accept(line);
+            }
+        } catch (Exception e) {
+            log.error("Problem reading file.");
+        }
+    }
+
+    public static void writeFile(String fileName, byte[] bytes) {
+        try (final FileOutputStream fileOut = new FileOutputStream(fileName)) {
+            fileOut.write(bytes);
+        } catch (Exception e) {
+            log.error("Problem writing file.");
+        }
+    }
+}

src/main/java/nl/rdb/java_examples/files/ReadAndWriteExample.java

@@ -0,0 +1,56 @@
+package nl.rdb.java_examples.files;
+
+import static nl.rdb.java_examples.files.FileUtil.readFile;
+import static nl.rdb.java_examples.files.FileUtil.writeFile;
+
+import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import lombok.extern.slf4j.Slf4j;
+import nl.rdb.java_examples.scanner.Example;
+
+@Slf4j
+public class ReadAndWriteExample {
+
+    @Example
+    void readAndWrite() {
+        String path = "";
+        String fileNameIn = "";
+
+        try (final BufferedReader file = new BufferedReader(new InputStreamReader(new FileInputStream("%s/%s".formatted(path, fileNameIn))))) {
+            StringBuilder builder = new StringBuilder();
+
+            for (String line = file.readLine(); line != null; line = file.readLine()) {
+                builder.append(Arrays.stream(line.split(";"))
+                        .collect(Collectors.joining("\";\"", "\"", "\"")));
+                builder.append('\n');
+            }
+
+            try (final FileOutputStream fileOut = new FileOutputStream(fileNameIn)) {
+                fileOut.write(builder.toString().getBytes());
+            }
+        } catch (Exception e) {
+            log.error("Problem reading file.");
+        }
+    }
+
+    @Example
+    void readAndWriteWithFileReader() {
+        String path = "";
+        String fileNameIn = "";
+
+        StringBuilder builder = new StringBuilder();
+
+        readFile("%s/%s".formatted(path, fileNameIn), line -> {
+            builder.append(Arrays.stream(line.split(";"))
+                    .collect(Collectors.joining("\";\"", "\"", "\"")));
+            builder.append('\n');
+        });
+
+        writeFile(fileNameIn, builder.toString().getBytes());
+    }
+}