“解析JSON字段值时出错。 意外的OBJECT_START在[16]，字段=添加“通过cURL向Solr添加记录

Question

Based on the example here (and other places), I am attempting to add a record to a simple Solr index (the only fields are src and dest, both single value string fields, and solrconfig is set to auto generate the id value) via PHP and cURL using the following code:

$data = array(
  "add" => array(
    "doc" => array(
      "src" => $src,
      "dest" => $dest
    ),
    "commitWithin" => 1000,
  ),
);

$data_string = json_encode(array($data));
$add_url = 'https://my-solr-url.com/solr/my_index/update?commit=true&wt=json';
$add_ch = curl_init($add_url);
curl_setopt($add_ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($add_ch, CURLOPT_POST, 1);
curl_setopt($add_ch, CURLOPT_HTTPHEADER, array('Content-type: application/json'));
curl_setopt($add_ch, CURLOPT_POSTFIELDS, $data_string);
$add_response = json_decode(curl_exec($add_ch));
curl_close($add_ch);

However, when I run it, I get the following error:

Error parsing JSON field value. Unexpected OBJECT_START at [16], field=add

Based on the Solr docs, I tried the following variation:

$data = array(
  'src' => $src,
  'dest' => $dest
);

$data_string = json_encode(array($data));
$add_url = 'https://my-solr-url.com/solr/my_index/update/json/docs?commit=true&wt=json';
$add_ch = curl_init($add_url);
curl_setopt($add_ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($add_ch, CURLOPT_POST, 1);
curl_setopt($add_ch, CURLOPT_HTTPHEADER, array('Content-type: application/json'));
curl_setopt($add_ch, CURLOPT_POSTFIELDS, $data_string);
$add_response = json_decode(curl_exec($add_ch));
curl_close($add_ch);

But now I get an error about Unknown field src. From what I can see, Im following the docs, but nothing works. What do I need to change?

Answer 1

So it turns out the issue was that I was creating a double array:

$data = array(
  "add" => array(
    "doc" => array(
      "src" => $src,
      "dest" => $dest
    ),
    "commitWithin" => 1000,
  ),
);

$data_string = json_encode(array($data));

Once I changed the last line to

$data_string = json_encode($data);

it worked fine.