From 994aaaabe4d6d4e07d11e09c47192bda977c08d8 Mon Sep 17 00:00:00 2001
From: Jan Zickermann <jan.zickermann@dataport.de>
Date: Tue, 11 Feb 2025 08:51:43 +0100
Subject: [PATCH] OZG-4097 send-attachment: Add LimitedInputStream
---
.../osiv2/storage/LimitedInputStream.java | 39 ++++++++++++++
.../osiv2/storage/LimitedInputStreamTest.java | 54 +++++++++++++++++++
2 files changed, 93 insertions(+)
create mode 100644 src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStream.java
create mode 100644 src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStreamTest.java
diff --git a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStream.java b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStream.java
new file mode 100644
index 0000000..c4c8ddf
--- /dev/null
+++ b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStream.java
@@ -0,0 +1,39 @@
+package de.ozgcloud.nachrichten.postfach.osiv2.storage;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+public class LimitedInputStream extends InputStream {
+ private final InputStream parentStream;
+ private final int limit;
+ private int readOffset = 0;
+
+ @Override
+ public int read() throws IOException {
+ var buffer = new byte[1];
+ var result = read(buffer, 0, 1);
+ return result < 0 ? result : buffer[0];
+ }
+
+
+ @Override
+ public int read(byte[] buffer, int offset, int length) throws IOException {
+ var remainingLength = limit - readOffset;
+ if (remainingLength > 0) {
+ var readLength = parentStream.read(buffer, offset, Math.min(remainingLength, length));
+ if (readLength > 0) {
+ readOffset += readLength;
+ return readLength;
+ }
+ }
+ return -1;
+ }
+
+ @Override
+ public void close() {
+ // Keep parent stream open
+ }
+}
diff --git a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStreamTest.java b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStreamTest.java
new file mode 100644
index 0000000..15c1600
--- /dev/null
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/storage/LimitedInputStreamTest.java
@@ -0,0 +1,54 @@
+package de.ozgcloud.nachrichten.postfach.osiv2.storage;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.io.ByteArrayInputStream;
+
+import org.apache.commons.io.IOUtils;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import lombok.SneakyThrows;
+
+class LimitedInputStreamTest {
+
+ @DisplayName("should limit input stream")
+ @Test
+ @SneakyThrows
+ void shouldLimitInputStream() {
+ var inputStream = createExampleLimitedInputStream();
+
+ var result = IOUtils.toByteArray(inputStream);
+
+ assertEquals("12345", new String(result));
+ }
+
+ @DisplayName("should read one")
+ @Test
+ @SneakyThrows
+ void shouldReadOne() {
+ var inputStream = createExampleLimitedInputStream();
+
+ var result = inputStream.read();
+
+ assertEquals('1', result);
+ }
+
+ @DisplayName("should keep parent stream usable")
+ @Test
+ @SneakyThrows
+ void shouldKeepParentStreamUsable() {
+ var parentStream = new ByteArrayInputStream("123456789".getBytes());
+ var inputStream = new LimitedInputStream(parentStream, 5);
+ var inputStream2 = new LimitedInputStream(parentStream, 5);
+ IOUtils.toByteArray(inputStream);
+
+ var result = IOUtils.toByteArray(inputStream2);
+
+ assertEquals("6789", new String(result));
+ }
+
+ private LimitedInputStream createExampleLimitedInputStream() {
+ return new LimitedInputStream(new ByteArrayInputStream("123456789".getBytes()), 5);
+ }
+}
\ No newline at end of file
--
GitLab