1 files changed, 62 insertions, 0 deletions

diff --git a/core/src/main/java/org/spongycastle/util/io/TeeOutputStream.java b/core/src/main/java/org/spongycastle/util/io/TeeOutputStream.java
new file mode 100644
index 00000000..c7cdcf6e
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/util/io/TeeOutputStream.java
@@ -0,0 +1,62 @@
+package org.spongycastle.util.io;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+
+/**
+ * An output stream which copies anything written into it to another stream.
+ */
+public class TeeOutputStream
+    extends OutputStream
+{
+    private OutputStream output1;
+    private OutputStream output2;
+
+    /**
+     * Base constructor.
+     *
+     * @param output1 the output stream that is wrapped.
+     * @param output2 a secondary stream that anything written to output1 is also written to.
+     */
+    public TeeOutputStream(OutputStream output1, OutputStream output2)
+    {
+        this.output1 = output1;
+        this.output2 = output2;
+    }
+
+    public void write(byte[] buf)
+        throws IOException
+    {
+        this.output1.write(buf);
+        this.output2.write(buf);
+    }
+
+    public void write(byte[] buf, int off, int len)
+        throws IOException
+    {
+        this.output1.write(buf, off, len);
+        this.output2.write(buf, off, len);
+    }
+
+    public void write(int b)
+        throws IOException
+    {
+        this.output1.write(b);
+        this.output2.write(b);
+    }
+
+    public void flush()
+        throws IOException
+    {
+        this.output1.flush();
+        this.output2.flush();
+    }
+
+    public void close()
+        throws IOException
+    {
+        this.output1.close();
+        this.output2.close();
+    }
+}
\ No newline at end of file