正文
PHP查询Elasticsearch数据，可以直接用Packagist中的类库elasticsearch/elasticsearch。具体安装方法，看一下过去的记录： PHP Elasticsearch查询服务示例。
查询条件一般用法：
$condition = [
"index" => "weberror-*",
"type" => "error",
"body" => [
"_source" => [
"includes" => ["user_id", "name", age"]
],
"from" => 0,
"size" => 100,
"query" => [
"bool"=>[
"filter"=> [
["match_phrase" => ["name" => "sam li"]],
["bool" => [
"must_not" => ["term" => ["name" => "harry"]]
]],
["bool" => [
"filter" => [
["match_phrase" => ["name" => "potter wang"]],
["bool" => [
"must_not" => ["term" => ["name" => "moon"]]
]]
]
]],
],
"should" => [
["term" => ["name" => "sam"]],
["range" => [
"age" => ["gte" => 18]
]],
["range" => [
"age" => ["lt" => 60]
]],
]
]
],
"sort" => [
"age" => [
"order"=>"desc"
],
"id" => [
"order"=>"asc"
]
]
]
];
$client = ClientBuilder::create()->setHosts(["http://127.0.0.1:9200","http://127.0.0.2:9200"])->build();
$response = $client->search($condition);
如果Elasticsearch查询不进行封装，代码看起来会很散，我们在Yii2中封装一下Elasticsearch查询，其实就是把最终输出的查询条件如上所示一样。
能不能改成下面Yii2 model使用的这种查询方式（流接口模式）呢？
UserInfo::find()
->select("user_id, user_name, age")
->where(["=" => ["userId" => 101]])
->addWhere(["like" => ["userName" => "zhang san"]])
->addWhere([
"add" => [
"<>" => ["userId" => 0,
"like" => ["userName" => "zhang"],
]
])
->setOrder(["age" => "desc"])
->setOffset(0)
->setLimit(10)
->search();
Es连接读取层 与 AR活动记录 首先要进行分离， AR活动记录 通过 ActiveQuery活动搜索层 对 Es连接读取层 进行数据读取。
整个模式有点类似中介者模式。ActiveQuery活动搜索层是中介，AR活动记录、Es连接读取层 是同事类。
Es连接读取层
<?php
namespace common\components;
use Elasticsearch\Client;
use Elasticsearch\ClientBuilder;
use yii\base\Component;
class LElasticSearch extends Component
{
public $host;
/** @var int */
public $retries = 3;
// HTTP handler
public $handler;
/** @var Client $instance */
private $instance;
public $timeout = 3;
public $connectTimeout = 3;
const arOperator = [
">",
">=",
"<",
"<=",
"or",
"and",
"like",
"in",
"=",
"not in",
"<>"
];
public function init()
{
if (!$this->handler) {
$this->handler = ClientBuilder::singleHandler();
}
$this->instance = ClientBuilder::create()->setHandler($this->handler)->setHosts($this->host)->setRetries($this->retries)->build();
}
public function getInstance()
{
return $this->instance;
}
public function search($param, $needBuild = true)
{
if ($needBuild) {
$param["body"] = $this->buildParam($param["body"]);
}
if (empty($param["client"]["timeout"])) {
$param["client"]["timeout"] = $this->timeout;
}
if (empty($param["client"]["connect_timeout"])) {
$param["client"]["connect_timeout"] = $this->connectTimeout;
}
$data = $this->instance->search($param);
$returnData = [
"count" => $data["hits"]["total"],
"list" => [],
];
if ($data["hits"]["hits"]){
$tmpData = [];
foreach ($data["hits"]["hits"] as $value)
{
$tmpData[] = $value["_source"];
}
$returnData["list"] = $tmpData;
}
return $returnData;
}
/**
* 数据结构，只支持简单查询，不支持group by
* @param $param
* e.g:
* {
* "select": ["sd","sd"],
* "where": {
* "and": [
* "in":["key":[1,3,4]],
* ">":["key":123],
* "or":[
* ["like": ["key":"value"]],
* ["=", ["key":"value"]]
* ],
* "like": ["key"=>"value"],
* ],
* "or":[
* ["like": ["key":"value"]],
* ["=", ["key":"value"]]
* ]
* },
* "order": [["dadf":"desc"],["asdf":"asc"]],
* "limit":5,
* "offset":6
* }
*
* @return mixed
*/
public function buildParam($param)
{
if (!is_array($param)) {
return $param;
}
$returnParam = [];
$condition = [];
// if (!empty($param["groupBy"]))
// {
// if (is_array($param["groupBy"]))
// {
// $newTmp = [];
// for ($i = count($param["groupBy"]); $i > 0; $i--)
// {
// $group = $param["groupBy"][$i-1];
// $tmp["aggs"] = [
// $group => [
// "terms" => [
// "field"=>$group,
// ]
// ]
// ];
// if ($newTmp == [])
// {
// $newTmp = $tmp;
// } else {
// $tmp["aggs"][$group] = $newTmp;
// $newTmp = $tmp;
// }
// }
// }
// $returnParam = $newTmp;
// }
if (!empty($param["select"])) {
$select = $param["select"];
if (is_string($select)) {
if (strpos($select, ",") !== false) {
$select = explode(",", $select);
}
}
$returnParam["_source"] = [
"includes" => $select,
];
}
if (!empty($param["limit"])) {
$returnParam["size"] = $param["limit"];
}
if (!empty($param["offset"])) {
$returnParam["from"] = $param["offset"];
}
if (!empty($param["order"])) {
foreach ($param["order"] as $value)
{
foreach ($value as $k => $v)
{
$returnParam["sort"][$k] = ["order" => $v];
}
}
}
if (!empty($param["where"])) {
foreach ($param["where"] as $key => $value) {
if ($key == "and")
{ //这里使用filter，主要是为了过滤，没必要使用must
if (is_array($value))
{
foreach ($value as $k => $v)
{
foreach ($v as $k1 => $v1)
{
if ($k1 == "and" || $k1 == "or")
{
$esCondition = $this->buildParam(["where" => [$k1 => $v1]]);
$condition["bool"]["filter"][] = $esCondition["query"];
} else {
$esCondition = $this->parse([$k1 => $v1]);
if ($esCondition)
{
$condition["bool"]["filter"][] = $esCondition;
}
}
}
}
}
} else if ($key == "or") {
if (is_array($value))
{
foreach ($value as $k => $v)
{
foreach ($v as $k1 => $v1)
{
if ($k1 == "and" || $k1 == "or")
{
$esCondition = $this->buildParam(["where" => [$k1 => $v1]]);
$condition["bool"]["should"][] = $esCondition["query"];
} else {
$esCondition = $this->parse([$k1 => $v1]);
if ($esCondition)
{
$condition["bool"]["should"][] = $esCondition;
}
}
}
}
}
}
}
}
if ($condition) {
$returnParam["query"] = $condition;
} else {
$returnParam["query"] = new \stdClass();
}
return $returnParam;
}
private function parse($param)
{
if (!is_array($param) || empty($param)) {
return false;
}
$condition = [];
foreach ($param as $key => $value)
{
switch ($key)
{
case "in":
$condition = [
"terms" => $value
];
break;
case "=":
$condition = [
"term" => $value
];
break;
case ">=":
$k = array_keys($value);
$v = array_values($value);
$condition = [
"range" => [
$k[0] => [
"gte" => $v[0]
]
]
];
break;
case ">":
$k = array_keys($value);
$v = array_values($value);
$condition = [
"range" => [
$k[0] => [
"gt" => $v[0]
]
]
];
break;
case "<":
$k = array_keys($value);
$v = array_values($value);
$condition = [
"range" => [
$k[0] => [
"lt" => $v[0]
]
]
];
break;
case "<=":
$k = array_keys($value);
$v = array_values($value);
$condition = [
"range" => [
$k[0] => [
"lte" => $v[0]
]
]
];
break;
case "like":
$condition = [
"match_phrase" => $value
];
break;
case "not in":
$condition = [
"bool" => [
"must_not" => [
"terms" => $value
]
]
];
break;
case "<>":
$condition = [
"bool" => [
"must_not" => [
"term" => $value
]
]
];
break;
case "_script":
$condition = [
"script" => [
"script" => $value,
]
];
break;
default:
$condition = false;
}
}
return $condition;
}
/**
* 是否存在操作符为key
* @param $param
* @return bool
*/
public function isExistOperator($param)
{
foreach ($param as $key => $value)
{
if (in_array($key, LElasticSearch::arOperator)) {
return true;
}
}
return false;
}
}
上面是LElasticSearch组件，写好config配置，Yii2项目加载时会自动初始化：
return [
...
"components" => [
...
"es" => [
"class" => "common\components\LElasticSearch",
"host" => [
"http://127.0.0.1:9200",
"http://127.0.0.2:9200",
],
],
],
"params" => [
...
],
...
];
AR活动记录
common\components\ES\ActiveRecordInterface 类：
<?php
namespace common\components\ES;
/**
* interface类，由model类实现
* Interface ActiveRecordInterface
* @package common\components\ES
*/
interface ActiveRecordInterface {
/**
* 获取es的链接
* @return mixed
*/
public static function getES();
/**
* 获取index
* @return mixed
*/
public static function getIndex();
/**
* 获取type
* @return mixed
*/
public static function getType();
/**
* key的对应关系
* @return mixed
*/
public function getMapping();
}
common\components\ES\ActiveRecord 类：
<?php
namespace common\components\ES;
use Yii;
abstract class ActiveRecord extends \ArrayObject implements ActiveRecordInterface
{
/**
* Populates an active record object using a row of data from the database/storage.
*
* This is an internal method meant to be called to create active record objects after
* fetching data from the database. It is mainly used by [[ActiveQuery]] to populate
* the query results into active records.
*
* When calling this method manually you should call [[afterFind()]] on the created
* record to trigger the [[EVENT_AFTER_FIND|afterFind Event]].
*
* @param BaseActiveRecord $record the record to be populated. In most cases this will be an instance
* created by [[instantiate()]] beforehand.
* @param array $row attribute values (name => value)
*/
public static function populateRecord($record, $row)
{
foreach ($row as $name => $value) {
$propertyName = $record->getProperty($record, $name);
if ($propertyName != null) {
$record->$propertyName = $value;
}
}
}
public function getProperty($record, $name)
{
$mapping = $record->getMapping();
return isset($mapping[$name]) ? $mapping[$name] : $name;
}
/**
* @inheritdoc
* @return ActiveQuery the newly created [[ActiveQuery]] instance.
*/
public static function find()
{
return Yii::createObject(ActiveQuery::className(), [get_called_class()]);
}
}
ActiveQuery活动搜索层
common\components\ES\ActiveQuery 类：
<?php
namespace common\components\ES;
use common\components\LElasticSearch;
use Yii;
use yii\base\BaseObject;
class ActiveQuery extends BaseObject
{
private $where = [];
private $sort = [];
private $select = [];
private $limit = 10;
private $offset = 0;
private $modelClass;
private $isArray = true;
public function asArray()
{
$this->isArray = true;
}
public function __construct($modelClass, $config = [])
{
$this->modelClass = $modelClass;
parent::__construct($config);
}
public function addWhere($where)
{
$this->where[] = $where;
return $this;
}
public function where($where)
{
$this->where = $where;
return $this;
}
public function select($select) {
$this->select = $select;
return $this;
}
public function addOrderBy($order) {
$this->sort[] = $order;
return $this;
}
public function setOrder($order)
{
$this->sort = $order;
return $this;
}
public function setOffset($offset)
{
$this->offset = $offset;
return $this;
}
public function setLimit($limit)
{
$this->limit = $limit;
return $this;
}
/**
* @param LElasticSearch $es
* @param bool $needBuild
* @return array
*/
public function search($es = null, $needBuild = true)
{
$modelClass = $this->modelClass;
$index = $modelClass::getIndex();
$type = $modelClass::getType();
$param = [
"index" => $index,
"type" => $type,
"body" => $this->getBody(),
];
if ($es == null) {
$es = $modelClass::getEs();
}
$searchData = $es->search($param, $needBuild);
if (count($searchData["list"]) == 0) {
return $searchData;
} else if (!$this->isArray) {
// 返回对象
$tmp = [];
foreach ($searchData["list"] as $value)
{
$tmp[] = $this->getActiveRecordModel($value);
}
$searchData["list"] = $tmp;
}
return $searchData;
}
/**
* 返回es的body数组，按照LElasticSearch来
*/
private function getBody()
{
$returnBody = [];
if ($this->where) {
$returnBody["where"] = ["and" => $this->where];
}
if ($this->select) {
$returnBody["select"] = $this->select;
}
if ($this->sort) {
$returnBody["order"] = $this->sort;
}
if ($this->limit) {
$returnBody["limit"] = $this->limit;
}
if ($this->offset) {
$returnBody["offset"] = $this->offset;
}
return $returnBody;
}
/**
* 返回ActiveRecord对象
* @param $data
* @return ActiveRecord
*/
private function getActiveRecordModel($data)
{
$modelClass = $this->modelClass;
/** @var ActiveRecord $class */
$class = new \ReflectionClass($modelClass);
$instance = $class->newInstance();
$modelClass::populateRecord($instance, $data);
return $instance;
}
public function one($es = null)
{
$this->limit=1;
$this->offset = 0;
return $this->search($es);
}
}
Model类
看个例子，common\esModels\UserInfo类：
<?php
namespace common\esModels;
use common\components\ES\ActiveRecord;
use Yii;
/**
* 用户类model
* Class UserInfo
* @package common\esModels
*/
class UserInfo extends ActiveRecord
{
/**
* 获取es的链接
* @return mixed
*/
public static function getES()
{
return Yii::$app->es;
}
/**
* @return mixed
*/
public static function getIndex()
{
return "user_info";
}
/**
* @return mixed
*/
public static function getType()
{
return "user_info";
}
public function getMapping()
{
return [
"userId" => "user_id",
"userName" => "user_name",
"age" => "age",
];
}
}
使用的时候：
<?php
namespace backend\controllers;
use common\esModels\UserInfo;
use Yii;
use yii\web\Controller;
class UserController extends Controller
{
public function actionGetUserInfoByUserId()
{
$user_id = 100;
if ($user_id) {
$condition = [
["=" => ["userId" => $user_id]]
];
return UserInfo::find()
->select("user_id, user_name, age")
->where($condition)
->addWhere(["like" => ["userName" => "zhang san"]])
->addWhere([
"add" => [
"<>" => ["userId" => 0,
"like" => ["userName" => "zhang"],
]
])
->setOrder(["age" => "desc"])
->setOffset(0)
->setLimit(10)
->search();
}
return [];
}
}
释疑点
new stdClass()
new stdClass()是PHP应用程序的一个变量。PHP可以用 $object = new StdClass(); 创建一个没有成员方法和属性的空对象。
很多时候，程序员们会将一些参数配置项之类的信息放在数组中使用，但是数组操作起来并不是很方便，很多时候使用对象操作符->xxx比数组操作符['xxx']要方便不少。
于是就需要创建一个空的对象，来将需要的属性名和属性值存储到对象中。
然而PHP中没有Javascript里面 var object = {}; 这样的语法。这是StdClass()出现的一个原因。
stdClass在PHP5才开始被流行。而stdClass也是zend的一个保留类。stdClass类是PHP的一个内部保留类，初始时没有成员变量也没成员方法，所有的魔术方法都被设置为NULL。 凡是用new stdClass()的变量，都不可能会出现$a->test()这种方式的使用。PHP5的对象的独特性，对象在任何地方被调用，都是引用地址型的，所以相对消耗的资源会少一点。 在其它页面为它赋值时是直接修改，而不是引用一个拷贝。 它可以用于手动实例化泛型对象，然后可以为这些对象设置成员变量，这对于将对象传递给其他希望以对象作为参数的函数或方法非常有用。 更可能的用法是将数组强制转换为一个对象，该对象接受数组中的每个值，并将其作为成员变量添加，其名称基于数组中的键。
PHP创建空对象可以使用下面这几种方法实现：
方法一：写一个空类
<?php
class cfg {}
$cfg = new cfg;
$cfg->dbhost = 'www.123.com';
echo $cfg->dbhost;
?>
勉强能完成任务，但是特别没有格局。
方法二：实例化 StdClass 类
<?php
$cfg = new StdClass();
$cfg->dbhost = 'www.123.com';
echo $cfg->dbhost;
?>
StdClass类是PHP中的一个基类。StdClass类没有任何成员方法，也没有任何成员属性，实例化以后就是一个空对象。
数组转为对象可以这么用：
<?php
function arrayToObject($array) {
if(!is_array($array)) {
return $array;
}
$object = new stdClass();
if (is_array($array) && count($array) > 0) {
foreach ($array as $name => $value) {
$name = strtolower(trim($name));
if (!empty($name)) {
$object->$name = $value;
}
}
return $object;
}
return FALSE;
}
?>
数组转为对象，也可以使用下面的方法。
方法三：使用json_encode()和json_decode()
这种方法就是把一个空的JSON对象通过json_decode()转变为PHP的StdClass空对象。 同样的道理，你可以将一个数组通过json_encode()转成JSON，再通过json_decode()将JSON转为StdClass对象。
<?php
$cfg = json_decode('{}');
$cfg->dbhost = 'www.123.com';
echo $cfg->dbhost;
?>
__CLASS__、get_class()与get_called_class()的区别
__CLASS__: 获取当前的类名；
get_class(): 获取当前调用方法的类名，或者可以理解成第一个调用的类；
get_called_class():获取当前主调类的类名，或者可以理解成最后一个调用的类；
看一下示例：
class A
{
public function say()
{
echo "A is " .__CLASS__ ."<br/>";
echo "A is " .get_class() ."<br/>";
echo "A is " .get_called_class() ."<br/>";
}
}
class B extends A
{
public function say()
{
parent::say();
echo "B is " .__CLASS__ ."<br/>";
echo "B is " .get_class() ."<br/>";
echo "B is " .get_called_class() ."<br/>";
}
}
$c = new B();
$c->say();
输出：
A is A
A is A
A is B
B is B
B is B
B is B
静态方法也一样：
class A
{
public static function say()
{
echo "A is " .__CLASS__ ."<br/>";
echo "A is " .get_class() ."<br/>";
echo "A is " .get_called_class() ."<br/>";
}
}
class B extends A
{
public static function say()
{
parent::say();
echo "B is " .__CLASS__ ."<br/>";
echo "B is " .get_class() ."<br/>";
echo "B is " .get_called_class() ."<br/>";
}
}
B::say();
输出：
A is A
A is A
A is B
B is B
B is B
B is B
下面这两种情况也可以看下，注意区别输出。
情况一：
class A
{
public function say()
{
echo "A is " .__CLASS__ ."<br/>";
echo "A is " .get_class() ."<br/>";
echo "A is " .get_called_class() ."<br/>";
}
}
class B extends A
{
public function say()
{
A::say();
echo "B is " .__CLASS__ ."<br/>";
echo "B is " .get_class() ."<br/>";
echo "B is " .get_called_class() ."<br/>";
}
}
$c = new B();
$c->say();
输出：
A is A
A is A
A is B
B is B
B is B
B is B
情况二：
class A
{
public static function say()
{
echo "A is " .__CLASS__ ."<br/>";
echo "A is " .get_class() ."<br/>";
echo "A is " .get_called_class() ."<br/>";
}
}
class B extends A
{
public static function say()
{
A::say();
echo "B is " .__CLASS__ ."<br/>";
echo "B is " .get_class() ."<br/>";
echo "B is " .get_called_class() ."<br/>";
}
}
B::say();
输出：
A is A
A is A
A is A
B is B
B is B
B is B
MVC框架中，涉及到单例时很好用，一般在基类中：
public static function getInstance()
{
$class_name = get_called_class();
if (isset(self::$instance[$class_name])) {
return self::$instance[$class_name];
}
self::$instance[$class_name] = new $class_name;
return self::$instance[$class_name];
}
其他类只要继承这个类，然后通过getInstance()就实现了单例模式。
如：
class A
{
private static $instance;
public static function getInstance()
{
$class_name = get_called_class();
if (isset(self::$instance[$class_name])) {
return self::$instance[$class_name];
}
self::$instance[$class_name] = new $class_name;
return self::$instance[$class_name];
}
public function say()
{
echo "A is " .__CLASS__ ."<br/>";
echo "A is " .get_class() ."<br/>";
echo "A is " .get_called_class() ."<br/>";
}
}
class B extends A
{
public function say()
{
parent::say();
echo "B is " .__CLASS__ ."<br/>";
echo "B is " .get_class() ."<br/>";
echo "B is " .get_called_class() ."<br/>";
}
}
$c = B::getInstance();
$c->say();
输出：
A is A
A is A
A is B
B is B
B is B
B is B
上面就是一个完整的例子：UserInfo Model类通过find()静态方法，
创建并返回一个ActiveQuery对象Yii::createObject(ActiveQuery::className(), [get_called_class()])，给参数modelClass赋值，
再通过select()、 addWhere()、 setOrder() 等 ActiveQuery对象方法给自己的其他参数赋值，
再通过ActiveQuery对象的search()方法调用Es连接读取层LElasticSearch实现Es查询。
ReflectionClass 类
我们看到上面用到了 ReflectionClass 类，这个类是做什么的？
官方解释：PHP 5 具有完整的反射 API，添加了对类、接口、函数、方法和扩展进行反向工程的能力。 此外，反射 API 提供了方法来取出函数、类和方法中的文档注释。
ReflectionClass 类报告了一个类的有关信息。
使用实例，如B类继承自A类，要取出B类中的方法。
classA.php:
class ClassA
{
public function funcAa(){}
public function funcAb(){}
public function funcAc(){}
}
classB.php:
include './classA.php';
class ClassB extends ClassA
{
public function funcBa(){}
public function funcBb(){}
public function funcBc(){}
public function funcAa(){
parent::funcAa();
}
}
当我需要找出ClassB里面的所有方法的时候，使用get_class_methods():
$classB = new ClassB;
$classFuncB = get_class_methods($classB);
echo '<pre>';
print_r($classFuncB);
输出：
Array
(
[0] => funcBa
[1] => funcBb
[2] => funcBc
[3] => funcAa
[4] => funcAb
[5] => funcAc
)
一共6个方法，实际上我不想要继承了ClassA里面的方法，我只想要ClassB的方法，怎么办呢？我稍微更改了如下：
$classA = new ClassA;
$classB = new ClassB;
$classFuncA = get_class_methods($classA);
$classFuncB = get_class_methods($classB);
echo '<pre>';
print_r(array_diff($classFuncB,$classFuncA));
输出：
Array
(
[0] => funcBa
[1] => funcBb
[2] => funcBc
)
少了一个方法 funcAa ，虽然funcAa是 ClassB 从 ClassA那里继承过来的，但是同样ClassB也有这个方法，所以不是我想要的结果。
解决方法，使用ReflectionClass：
$reflection = new ReflectionClass('ClassB');
print_r($reflection->getMethods());
输出：
Array
(
[0] => ReflectionMethod Object
(
[name] => funcBa
[class] => ClassB
)
[1] => ReflectionMethod Object
(
[name] => funcBb
[class] => ClassB
)
[2] => ReflectionMethod Object
(
[name] => funcBc
[class] => ClassB
)
[3] => ReflectionMethod Object
(
[name] => funcAa
[class] => ClassB
)
[4] => ReflectionMethod Object
(
[name] => funcAb
[class] => ClassA
)
[5] => ReflectionMethod Object
(
[name] => funcAc
[class] => ClassA
)
)
可以看到 [4]、[5] 里面的class 对应的值是ClassA，而其他对应的值都是ClassB。通过这个可以用foreach来实现最后想要的结果：
$reflection = new ReflectionClass('ClassB');
$array = '';
foreach ($reflection->getMethods() as $obj) {
if ($obj->class == $reflection->getName()) { //$reflection->getName() 获取类名
$array[] = $obj->name;
}
}
echo '<pre>';
print_r($array);
输出：
Array
(
[0] => funcBa
[1] => funcBb
[2] => funcBc
[3] => funcAa
)
ReflectionClass::newInstance
ReflectionClass::newInstance ， 从指定的参数创建一个新的类实例。
示例：
// 定义一个类
class fuc
{
static function ec()
{
echo '我是一个类';
}
}
//建立 fuc这个类的反射类
$class = new ReflectionClass('fuc');
// 用法1
$fuc = $class->newInstance(); //相当于实例化 fuc 类
$fuc->ec(); //执行 fuc 里的方法ec /*最后输出:我是一个类*/
// 用法2
$ec = $class->getmethod('ec'); //获取fuc 类中的ec方法
$fuc = $class->newInstance(); //实例化
$ec->invoke($fuc); //执行ec 方法
上面的过程很熟悉吧。其实和调用对象的方法类似，只不过这里是反着来的，方法在前，对象在后。
ReflectionFunction::invoke 调用反射函数：
ReflectionFunction::invoke( [ mixed $... ] )
看个例子：
function title($title, $name)
{
return sprintf("%s. %s\r\n", $title, $name);
}
$function = new ReflectionFunction('title');
echo $function->invoke('Dr', 'Phil');
还有一个容易引起误解的魔术方法__invoke()，
php中的__invoke()魔术方法作用是直接调用对象名当方法使用时，就调用的是__invoke()方法。
class Test
{
function __invoke()
{
var_dump("当显示这段话时，是把对象当做方法来用");
}
}
$test = new Test();//实例化一个对象
$test();//将对象当做方法来使
如果去掉__invoke()方法，还是将对象当做方法来使用时，就会报错。
参考资料
elastic/elasticsearch-php https://github.com/elastic/elasticsearch-php
Packagist elasticsearch/elasticsearch https://packagist.org/packages/elasticsearch/elasticsearch
PHP Elasticsearch查询服务示例 https://ibaiyang.github.io/blog/php/2018/12/27/PHP-Elasticsearch查询服务示例.html
linux 安装Elasticsearch https://ibaiyang.github.io/blog/linux/2020/04/01/linux-%E5%AE%89%E8%A3%85Elasticsearch.html
PHP new StdClass() 创建空对象 https://www.51-n.com/t-4421-1-1.html
get_called_class() 和 get_class() 的区别 <get_called_class() 和 get_class() 的区别>
PHP 手册 函数参考 变量与类型相关扩展 反射 ReflectionClass 类 https://www.php.net/manual/zh/class.reflectionclass.php
PHP 反射 ReflectionClass https://www.cnblogs.com/uduemc/p/4055092.html
PHP 手册 函数参考 变量与类型相关扩展 反射 ReflectionClass ReflectionClass::newInstance https://www.php.net/manual/zh/reflectionclass.newinstance.php
PHP ReflectionFunction::invoke 反射函数 https://www.jc2182.com/php/php-reflectionfunctioninvoke-ref.html