Add HTMLFileRenderer that writes the HTML string into a file.

src/main/java/ch/fritteli/labyrinth/HTMLFileRenderer.java

@@ -0,0 +1,47 @@
+package ch.fritteli.labyrinth;
+
+import lombok.NonNull;
+import lombok.Setter;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+
+public class HTMLFileRenderer implements Renderer<Path> {
+    @Setter
+    private Path targetFile;
+
+    private HTMLFileRenderer() {
+        try {
+            this.targetFile = Files.createTempFile("labyrinth_", ".html");
+        } catch (IOException e) {
+            System.err.println("Unable to set default target file.");
+            e.printStackTrace();
+        }
+    }
+
+    @NonNull
+    public static HTMLFileRenderer newInstance() {
+        return new HTMLFileRenderer();
+    }
+
+    public boolean isTargetFileDefinedAndWritable() {
+        return this.targetFile != null && this.targetFile.toFile().canWrite();
+    }
+
+    @Override
+    public Path render(@NonNull final Labyrinth labyrinth) {
+        if (!this.isTargetFileDefinedAndWritable()) {
+            throw new IllegalArgumentException("Cannot write to target file. See previous log messages for details.");
+        }
+        final String html = HTMLRenderer.newInstance().render(labyrinth);
+        try {
+            Files.writeString(this.targetFile, html, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE);
+        } catch (IOException e) {
+            System.err.println("Failed writing to file " + this.targetFile.normalize().toString());
+            e.printStackTrace();
+        }
+        return targetFile;
+    }
+}

src/main/java/ch/fritteli/labyrinth/Main.java

@@ -4,13 +4,14 @@ import lombok.NonNull;
 
 public class Main {
     public static void main(@NonNull final String[] args) {
-        int width = 10;
-        int height = 10;
+        int width = 100;
+        int height = 100;
         final Labyrinth labyrinth = new Labyrinth(width, height);
         final TextRenderer textRenderer = TextRenderer.newInstance();
         System.out.println(textRenderer.render(labyrinth));
         System.out.println(textRenderer.setRenderingSolution(true).render(labyrinth));
         final HTMLRenderer htmlRenderer = HTMLRenderer.newInstance();
         System.out.println(htmlRenderer.render(labyrinth));
+        System.out.println(HTMLFileRenderer.newInstance().render(labyrinth));
     }
 }

src/main/java/ch/fritteli/labyrinth/TextRenderer.java

@@ -13,11 +13,11 @@ public class TextRenderer implements Renderer<String> {
     private int height;
     private boolean renderSolution;
     // column counter
-    private int x = 0;
+    private int x;
     // row counter
-    private int y = 0;
+    private int y;
     // line counter (top-, center- or bottom line of a row)
-    private int line = 0;
+    private int line;
 
     private TextRenderer() {
         this.renderSolution = false;
@@ -42,6 +42,9 @@ public class TextRenderer implements Renderer<String> {
         if (this.width == 0 || this.height == 0) {
             return "";
         }
+        this.x = 0;
+        this.y = 0;
+        this.line = 0;
         final StringBuilder sb = new StringBuilder();
         while (this.hasNext()) {
             sb.append(this.next());