didi/DoKit · error · IllegalArgumentException

Stream may not be null.

Error message

Stream may not be null.

What it means

Downloader.Response's stream constructor throws IllegalArgumentException when stream is null. A Response in stream mode must expose the image bytes through an InputStream; a custom Downloader must pass an open stream. Fail-fast null guard.

Source

Thrown at Android/dokit/src/main/java/com/didichuxing/doraemonkit/picasso/Downloader.java:118

     * @deprecated The {@code contentLength} argument value is ignored. Use {@link #Response(Bitmap,
     * boolean)}.
     */
    @Deprecated @SuppressWarnings("UnusedDeclaration")
    public Response(Bitmap bitmap, boolean loadedFromCache, long contentLength) {
      this(bitmap, loadedFromCache);
    }

    /**
     * Response stream and info.
     *
     * @param stream Image data stream.
     * @param loadedFromCache {@code true} if the source of the stream is from a local disk cache.
     * @param contentLength The content length of the response, typically derived by the
     * {@code Content-Length} HTTP header.
     */
    public Response(InputStream stream, boolean loadedFromCache, long contentLength) {
      if (stream == null) {
        throw new IllegalArgumentException("Stream may not be null.");
      }
      this.stream = stream;
      this.bitmap = null;
      this.cached = loadedFromCache;
      this.contentLength = contentLength;
    }

    /**
     * Input stream containing image data.
     * <p>
     * If this returns {@code null}, image data will be available via {@link #getBitmap()}.
     */
    public InputStream getInputStream() {
      return stream;
    }

    /**
     * Bitmap representing the image.

View on GitHub (pinned to 626827cddb)

Solutions

1. Return a real, open InputStream in the Response
2. If the stream cannot be opened, throw an IOException from the Downloader instead of constructing a Response with null
3. Verify the underlying connection/cache actually produced a stream before building the Response

Example fix

// before
InputStream is = openQuietly(url);
return new Response(is, false, len); // IllegalArgumentException when is == null

// after
InputStream is = openStream(url); // throws IOException on failure
return new Response(is, false, len);

InputStream is = urlConnection.getInputStream(); // throws IOException on failure
return new Response(is, false, urlConnection.getContentLength());

try { return new Response(open(url), false, len); } catch (IllegalArgumentException e) { throw new IOException("stream open failed", e); }

When it happens

Trigger: Implementing a custom Downloader and returning new Response(null, false, contentLength) when the connection or cache stream could not be opened.

Common situations: Custom downloaders where openStream() fails silently and returns null instead of throwing; wrappers around okhttp whose body().byteStream() was consumed or closed earlier.

Related errors

• Bitmap may not be null.
• Downloader must not be null.
• Executor service must not be null.
• Memory cache must not be null.
• Listener must not be null.

AI-assisted analysis of didi/DoKit@626827cddb (2026-08-14). Data as JSON: /api/errors/9f5f43f3e235522b. Report an issue: GitHub.