ABP/Android proxy service

src/org/adblockplus/ChunkedOutputStream.java

+package org.adblockplus;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * ChunkedOutputStream implements chunked HTTP transfer encoding wrapper for
+ * OutputStream.
+ */
+public class ChunkedOutputStream extends FilterOutputStream
+{
+  private static final byte[] CRLF = {'\r', '\n'};
+  private static final byte[] FINAL_CHUNK = new byte[] {'0', '\r', '\n', '\r', '\n'};
+  private boolean wroteFinalChunk = false;
+
+  public ChunkedOutputStream(OutputStream out)
+  {
+    super(out);
+  }
+
+  @Override
+  public void close() throws IOException
+  {
+    if (!wroteFinalChunk)
+      writeFinalChunk();
+    super.close();
+  }
+
+  @Override
+  public void write(byte[] buffer, int offset, int length) throws IOException
+  {
+    writeChunk(buffer, offset, length);
+  }
+
+  @Override
+  public void write(byte[] buffer) throws IOException
+  {
+    writeChunk(buffer, 0, buffer.length);
+  }
+
+  @Override
+  public void write(int oneByte) throws IOException
+  {
+    throw new UnsupportedOperationException("Not implemented");
+  }
+
+  public void writeFinalChunk() throws IOException
+  {
+    out.write(FINAL_CHUNK);
+    out.flush();
+    wroteFinalChunk = true;
+  }
+
+  private void writeChunk(byte buffer[], int offset, int length) throws IOException
+  {
+    // Zero sized buffers are ok on slow connections but not in our case - zero
+    // chunk is used to indicate the end of transfer.
+    if (length > 0)
+    {
+      // Write the chunk length as a hex number
+      writeHex(length);
+      // Write the data
+      out.write(buffer, offset, length);
+      // Write a CRLF
+      out.write(CRLF);
+      // Flush the underlying stream
+      out.flush();
+    }
+  }
+
+  private void writeHex(int i) throws IOException
+  {
+    out.write(Integer.toHexString(i).getBytes());
+    out.write(CRLF);
+  }
+}