搜索关键字，使结果高亮关键字，类似百度搜索结果一样，如下图。
关键字高亮.png
在PHP中，调用elasticsearch进行搜索时，想让结果高亮显示，添加参数highlight，在其下的field中，添加需要高亮的字段，之前写成'content => []'，没有返回高亮结果。
后来通过搜索查询相关问答网站，才知道需要将类型数组转换为对象，如'content' => new \stdClass()。
public function search()
{
$hosts = ['127.0.0.1:9200'];
$clientBuilder = ClientBuilder::create(); // Instantiate a new ClientBuilder
$clientBuilder->setHosts($hosts); // Set the hosts
$client = $clientBuilder->build(); // Build the client object
//Set search params
$params = [
'index' => 'index',
'type' => 'fulltext',
'body' => [
'query' => [
'term' => [
'content' => '中国'
]
],
'highlight' => [
'pre_tags' => ["<em>"],
'post_tags' => ["</em>"],
'fields' => [
"content" => new \stdClass()
]
]
]
];
$response = $client->search($params);
print_r($response);
}
返回的结果如下，查询关键字“中国”，返回的结果中，在highlight中，标签<em>高亮包含了“中国”：
Array
(
[took] => 2
[timed_out] =>
[_shards] => Array
(
[total] => 5
[successful] => 5
[failed] => 0
)
[hits] => Array
(
[total] => 2
[max_score] => 1.5
[hits] => Array
(
[0] => Array
(
[_index] => index
[_type] => fulltext
[_id] => 4
[_score] => 1.5
[_source] => Array
(
[content] => 中国驻洛杉矶领事馆遭亚裔男子枪击 嫌犯已自首
)
[highlight] => Array
(
[content] => Array
(
[0] =>
<em>中国</em>驻洛杉矶领事馆遭亚裔男子枪击 嫌犯已自首
)
)
)
[1] => Array
(
[_index] => index
[_type] => fulltext
[_id] => 3
[_score] => 0.53699243
[_source] => Array
(
[content] => 中韩渔警冲突调查：韩警平均每天扣1艘中国渔船
)
[highlight] => Array
(
[content] => Array
(
[0] => 中韩渔警冲突调查：韩警平均每天扣1艘
<em>中国</em>渔船
)
)
)
)
)
)
