get_class_methods() 获取类的方法外（但这个只可以获取 public 类型的方法），还可以通过 ReflectionClass 来获取，是一个 debug 的好方法，尤其对于使用某个扩展类，而文档不全的情况下。
ReflectionClass 类报告了一个类的有关信息，比如通过调用 ReflectionClass ，来获取 protobuf 3 中支持的方法列表：
<?php
$class = new ReflectionClass('\Google\Protobuf\Internal\Message');
$methods = $class->getMethods();
print_r($methods);die;
返回结果：
array(14) {
[0]=>
object(ReflectionMethod)#3 (2) {
["name"]=>
string(5) "clear"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[1]=>
object(ReflectionMethod)#4 (2) {
["name"]=>
string(20) "discardUnknownFields"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[2]=>
object(ReflectionMethod)#5 (2) {
["name"]=>
string(17) "serializeToString"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[3]=>
object(ReflectionMethod)#6 (2) {
["name"]=>
string(15) "mergeFromString"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[4]=>
object(ReflectionMethod)#7 (2) {
["name"]=>
string(21) "serializeToJsonString"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[5]=>
object(ReflectionMethod)#8 (2) {
["name"]=>
string(19) "mergeFromJsonString"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[6]=>
object(ReflectionMethod)#9 (2) {
["name"]=>
string(9) "mergeFrom"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[7]=>
object(ReflectionMethod)#10 (2) {
["name"]=>
string(16) "readWrapperValue"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[8]=>
object(ReflectionMethod)#11 (2) {
["name"]=>
string(17) "writeWrapperValue"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[9]=>
object(ReflectionMethod)#12 (2) {
["name"]=>
string(8) "hasOneof"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[10]=>
object(ReflectionMethod)#13 (2) {
["name"]=>
string(9) "readOneof"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[11]=>
object(ReflectionMethod)#14 (2) {
["name"]=>
string(10) "writeOneof"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[12]=>
object(ReflectionMethod)#15 (2) {
["name"]=>
string(10) "whichOneof"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
[13]=>
object(ReflectionMethod)#16 (2) {
["name"]=>
string(11) "__construct"
["class"]=>
string(32) "Google\Protobuf\Internal\Message"
}
}