@Test
  public void testLongHeader() throws Exception {
    URL url = new URL(baseUrl, "/longheader");
    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < 63 * 1024; i++) {
      sb.append("a");
    }
    conn.setRequestProperty("longheader", sb.toString());
    assertEquals(HttpURLConnection.HTTP_OK, conn.getResponseCode());
  }
Test that verifies headers can be up to 64K long. The test adds a 63K header leaving 1K for
other headers. This is because the header buffer setting is for ALL headers, names and values
included.
hbase-http/src/test/java/org/apache/hadoop/hbase/http/TestHttpServer.java