tursodatabase/turso · error · SQLException

setCharacterStream length must be non-negative

Error message

setCharacterStream length must be non-negative

What it means

Thrown by setCharacterStream(int, Reader, int) when length is negative. The driver validates the length before copying length chars from the Reader into a String: a null Reader binds SQL NULL and a zero length binds an empty string; only negative lengths throw.

Source

Thrown at bindings/java/src/main/java/tech/turso/jdbc4/JDBC4PreparedStatement.java:408

    batchQueryParams.add(currentBatchParams);
    currentBatchParams = new Object[paramCount];
  }

  @Override
  public void addBatch(String sql) throws SQLException {
    throw new SQLException("addBatch(String) cannot be called on a PreparedStatement");
  }

  @Override
  public void setCharacterStream(int parameterIndex, @Nullable Reader reader, int length)
      throws SQLException {
    requireNonNull(this.statement);
    if (reader == null) {
      setParam(parameterIndex, null);
      return;
    }
    if (length < 0) {
      throw new SQLException("setCharacterStream length must be non-negative");
    }
    if (length == 0) {
      setParam(parameterIndex, "");
      return;
    }
    try {
      char[] buffer = new char[length];
      int offset = 0;
      int read;
      while (offset < length && (read = reader.read(buffer, offset, length - offset)) > 0) {
        offset += read;
      }
      String value = new String(buffer, 0, offset);
      setParam(parameterIndex, value);
    } catch (IOException e) {
      throw new SQLException("Error reading character stream", e);
    }
  }

View on GitHub (pinned to bad083fafb)

Solutions

1. Pass a non-negative char count.
2. Use the no-length overload setCharacterStream(i, reader), which reads until EOF.
3. To bind NULL, use setNull(i, Types.VARCHAR) or pass a null Reader.

Example fix

// before
ps.setCharacterStream(1, reader, -1); // throws

// after
ps.setCharacterStream(1, reader); // reads until EOF

if (length < 0) {
    throw new IllegalArgumentException("length must be >= 0, got " + length);
}
ps.setCharacterStream(1, reader, length);

catch (SQLException e) {
    if (e.getMessage() != null && e.getMessage().contains("non-negative")) {
        // fix the length argument or switch to the no-length overload
    }
    throw e;
}

When it happens

Trigger: ps.setCharacterStream(i, reader, -1); forwarding a computed char count that underflowed or defaulted to -1; using the InputStream.read() -1-equals-EOF convention where a length is expected.

Common situations: DAO layers that accept an optional length and pass -1 when unknown; counts from external systems stored in signed ints; sentinel conventions copied from other drivers.

Related errors

• setAsciiStream length must be non-negative
• setBinaryStream length must be non-negative
• Error reading ASCII stream
• setUnicodeStream length must be non-negative
• Error reading Unicode stream

AI-assisted analysis of tursodatabase/turso@bad083fafb (2026-08-16). Data as JSON: /api/errors/d7741a52cb5c11bb. Report an issue: GitHub.