Add WIP Java language bindings

src/bindings/java/ZeroTierOutputStream.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c)2013-2021 ZeroTier, Inc.
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file in the project's root directory.
+ *
+ * Change Date: 2026-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2.0 of the Apache License.
+ */
+/****/
+
+package com.zerotier.sdk;
+
+import com.zerotier.sdk.*;
+import java.io.*;
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * Extends OutputStream using ZeroTier as a transport
+ */
+public class ZeroTierOutputStream extends OutputStream {
+    /**
+     * File descriptor used by lower native layer
+     */
+    public int zfd = -1;
+
+    /**
+     * Close the stream
+     * @exception IOException when an I/O error occurs
+     */
+    public void close() throws IOException
+    {
+        /* Note: this operation currently only stops RX on a socket that is
+        shared between both I/OStreams. This means that closing this stream
+        will only shutdown that aspect of the socket but not actually close
+        it and free resources. Resources will be properly freed when the
+        socket implementation's native close() is called or if both I/OStreams
+        are closed separately */
+        ZeroTierNative.zts_shutdown(zfd, ZeroTierNative.ZTS_SHUT_WR);
+        zfd = -1;
+    }
+
+    /**
+     * Write a buffer
+     * @param originBuffer Source buffer
+     * @exception IOException when an I/O error occurs
+     */
+    public void write(byte[] originBuffer) throws IOException
+    {
+        int bytesWritten = ZeroTierNative.zts_write(zfd, originBuffer);
+        if (bytesWritten < 0) {
+            throw new IOException("write(originBuffer[]), errno=" + bytesWritten);
+        }
+    }
+
+    /**
+     * Write a buffer at offset
+     * @param originBuffer Source buffer
+     * @param offset Where in the buffer to start
+     * @param numBytes Number of bytes to write
+     * @exception IOException when an I/O error occurs
+     */
+    public void write(byte[] originBuffer, int offset, int numBytes) throws IOException
+    {
+        Objects.requireNonNull(originBuffer, "input byte array (originBuffer) must not be null");
+        if (offset < 0) {
+            throw new IndexOutOfBoundsException("offset < 0");
+        }
+        if (numBytes < 0) {
+            throw new IndexOutOfBoundsException("numBytes < 0");
+        }
+        if ((offset + numBytes) > originBuffer.length) {
+            throw new IndexOutOfBoundsException("(offset+numBytes) > originBuffer.length");
+        }
+        int bytesWritten = ZeroTierNative.zts_write_offset(zfd, originBuffer, offset, numBytes);
+        if (bytesWritten < 0) {
+            throw new IOException("write(originBuffer[],offset,numBytes), errno=" + bytesWritten);
+        }
+    }
+
+    /**
+     * Write low byte
+     * @param d Integer containing low byte to write
+     * @exception IOException when an I/O error occurs
+     */
+    public void write(int d) throws IOException
+    {
+        byte lowByte = (byte)(d & 0xFF);
+        int bytesWritten = ZeroTierNative.zts_write_byte(zfd, lowByte);
+        if (bytesWritten < 0) {
+            throw new IOException("write(d), errno=" + bytesWritten);
+        }
+    }
+}