From 7d8c75e4dacc92810e16bd3eb9d3cd6d8012f10b Mon Sep 17 00:00:00 2001
From: Anton Oellerer <13524304+AntonOellerer@users.noreply.github.com>
Date: Thu, 7 Nov 2024 11:53:14 +0100
Subject: [PATCH] Update image save workflow

* throw new checked exception if format not found
* add `saveAsPng` method
---
 build.gradle                                  |  2 +-
 .../jocument/image/DefaultImageReference.java | 19 ++++++++++++++-----
 .../jocument/image/ImageReference.java        |  6 ++++--
 .../image/NoWriterFoundException.java         |  7 +++++++
 4 files changed, 26 insertions(+), 8 deletions(-)
 create mode 100644 src/main/java/com/docutools/jocument/image/NoWriterFoundException.java

diff --git a/build.gradle b/build.gradle
index dd6bb279..98fb9cbb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,7 +8,7 @@ plugins {
 }
 
 group 'com.docutools'
-version = '4.2.8'
+version = '5.0.0'
 
 java {
     toolchain {
diff --git a/src/main/java/com/docutools/jocument/image/DefaultImageReference.java b/src/main/java/com/docutools/jocument/image/DefaultImageReference.java
index 18021e75..5e342963 100644
--- a/src/main/java/com/docutools/jocument/image/DefaultImageReference.java
+++ b/src/main/java/com/docutools/jocument/image/DefaultImageReference.java
@@ -40,19 +40,28 @@ public BufferedImage getImage() {
   }
 
   @Override
-  public Path saveAsJpeg() throws IOException {
+  public Path saveAsJpeg() throws IOException, NoWriterFoundException {
+    return saveAs(".jpg", "JPEG");
+  }
+
+  @Override
+  public Path saveAsPng() throws IOException, NoWriterFoundException {
+    return saveAs(".png", "PNG");
+  }
+
+  private Path saveAs(String suffix, String formatName) throws IOException, NoWriterFoundException {
     if (image == null) {
       throw new ImageReferenceClosedException("Image was already closed.");
     }
 
-    var filePath = Files.createTempFile("jocument-", ".jpg");
+    var filePath = Files.createTempFile("jocument-", suffix);
     log.trace("Saving image {} to '{}'...", id, filePath);
 
-    boolean foundWriter = ImageIO.write(image, "JPEG", filePath.toFile());
+    boolean foundWriter = ImageIO.write(image, formatName, filePath.toFile());
     if (!foundWriter) {
-      throw new IOException("Found no JPG writer");
+      throw new NoWriterFoundException(formatName);
     }
-    log.trace("Successfully saved image {} to '{}'!", id, filePath);
+    log.trace("Successfully saved image {} to '{}'", id, filePath);
 
     return filePath;
   }
diff --git a/src/main/java/com/docutools/jocument/image/ImageReference.java b/src/main/java/com/docutools/jocument/image/ImageReference.java
index 0444a731..f2ca9e89 100644
--- a/src/main/java/com/docutools/jocument/image/ImageReference.java
+++ b/src/main/java/com/docutools/jocument/image/ImageReference.java
@@ -24,7 +24,7 @@ public abstract class ImageReference implements AutoCloseable {
    * @param width width in pixel
    * @param height height in pixel
    */
-  public ImageReference(int width, int height) {
+  protected ImageReference(int width, int height) {
     this.id = UUID.randomUUID();
     this.width = width;
     this.height = height;
@@ -62,7 +62,9 @@ public int getHeight() {
    *
    * @return the {@link Path} to the JPEG
    */
-  public abstract Path saveAsJpeg() throws IOException;
+  public abstract Path saveAsJpeg() throws IOException, NoWriterFoundException;
+
+  public abstract Path saveAsPng() throws IOException, NoWriterFoundException;
 
   @Override
   public abstract void close();
diff --git a/src/main/java/com/docutools/jocument/image/NoWriterFoundException.java b/src/main/java/com/docutools/jocument/image/NoWriterFoundException.java
new file mode 100644
index 00000000..97924708
--- /dev/null
+++ b/src/main/java/com/docutools/jocument/image/NoWriterFoundException.java
@@ -0,0 +1,7 @@
+package com.docutools.jocument.image;
+
+public class NoWriterFoundException extends Exception {
+  public NoWriterFoundException(String type) {
+    super("Found no writer for type %s".formatted(type));
+  }
+}