diff --git a/sop-java/src/main/java/sop/Ready.java b/sop-java/src/main/java/sop/Ready.java
deleted file mode 100644
index 71ab26e..0000000
--- a/sop-java/src/main/java/sop/Ready.java
+++ /dev/null
@@ -1,45 +0,0 @@
-// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package sop;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-
-public abstract class Ready {
-
-    /**
-     * Write the data to the provided output stream.
-     *
-     * @param outputStream output stream
-     * @throws IOException in case of an IO error
-     */
-    public abstract void writeTo(OutputStream outputStream) throws IOException;
-
-    /**
-     * Return the data as a byte array by writing it to a {@link ByteArrayOutputStream} first and then returning
-     * the array.
-     *
-     * @return data as byte array
-     * @throws IOException in case of an IO error
-     */
-    public byte[] getBytes() throws IOException {
-        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
-        writeTo(bytes);
-        return bytes.toByteArray();
-    }
-
-    /**
-     * Return an input stream containing the data.
-     *
-     * @return input stream
-     * @throws IOException in case of an IO error
-     */
-    public InputStream getInputStream() throws IOException {
-        return new ByteArrayInputStream(getBytes());
-    }
-}
diff --git a/sop-java/src/main/kotlin/sop/Ready.kt b/sop-java/src/main/kotlin/sop/Ready.kt
new file mode 100644
index 0000000..1eb3fb3
--- /dev/null
+++ b/sop-java/src/main/kotlin/sop/Ready.kt
@@ -0,0 +1,49 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop
+
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.io.IOException
+import java.io.InputStream
+import java.io.OutputStream
+
+/** Abstract class that encapsulates output data, waiting to be consumed. */
+abstract class Ready {
+
+    /**
+     * Write the data to the provided output stream.
+     *
+     * @param outputStream output stream
+     * @throws IOException in case of an IO error
+     */
+    @Throws(IOException::class) abstract fun writeTo(outputStream: OutputStream)
+
+    /**
+     * Return the data as a byte array by writing it to a [ByteArrayOutputStream] first and then
+     * returning the array.
+     *
+     * @return data as byte array
+     * @throws IOException in case of an IO error
+     */
+    val bytes: ByteArray
+        @Throws(IOException::class)
+        get() =
+            ByteArrayOutputStream()
+                .let {
+                    writeTo(it)
+                    it
+                }
+                .toByteArray()
+
+    /**
+     * Return an input stream containing the data.
+     *
+     * @return input stream
+     * @throws IOException in case of an IO error
+     */
+    val inputStream: InputStream
+        @Throws(IOException::class) get() = ByteArrayInputStream(bytes)
+}