PHP message: PHP Fatal error: Uncaught Error: Class 'Mongo' not found

Ubunt 16.04 + Nginx  + PHP7 + MongoDB3.2.9 + Mongo-PHP_driver 1.40

搭好环境后写了个脚本：

<?php  

$connection = new Mongo();

?> 

通过网页访问，网页显示空白，查看nginx 的错误日志是：

"PHP message: PHP Fatal error:  Uncaught Error: Class 'Mongo' not found in /var/www/phpscripts/mongo.php:2

找不到Mongo这个类，

通过函数 get_extension_funcs 和get_declared_classes查看mongo提供的类名和函数名

print_r(get_extension_funcs('mongodb')); #看一下该扩展中提供了那些函数

print_r(get_declared_classes()); #看一下预定义类中是否有你需要（或相似）的类名

Array

(

    [0] => MongoDB\BSON\fromPHP

    [1] => MongoDB\BSON\toPHP

    [2] => MongoDB\BSON\toJSON

    [3] => MongoDB\BSON\fromJSON

)

Array

(

    [0] => stdClass

    [1] => Exception

    [2] => ErrorException

    [3] => Error

    [4] => ParseError

    [5] => TypeError

    [6] => ArithmeticError

    [7] => DivisionByZeroError

    [8] => Closure

    [9] => Generator

    [10] => ClosedGeneratorException

    [11] => DateTime

    [12] => DateTimeImmutable

    [13] => DateTimeZone

    [14] => DateInterval

    [15] => DatePeriod

    [16] => LogicException

    [17] => BadFunctionCallException

    [18] => BadMethodCallException

    [19] => DomainException

    [20] => InvalidArgumentException

    [21] => LengthException

    [22] => OutOfRangeException

    [23] => RuntimeException

    [24] => OutOfBoundsException

    [25] => OverflowException

    [26] => RangeException

    [27] => UnderflowException

    [28] => UnexpectedValueException

    [29] => RecursiveIteratorIterator

    [30] => IteratorIterator

    [31] => FilterIterator

    [32] => RecursiveFilterIterator

    [33] => CallbackFilterIterator

    [34] => RecursiveCallbackFilterIterator

    [35] => ParentIterator

    [36] => LimitIterator

    [37] => CachingIterator

    [38] => RecursiveCachingIterator

    [39] => NoRewindIterator

    [40] => AppendIterator

    [41] => InfiniteIterator

    [42] => RegexIterator

    [43] => RecursiveRegexIterator

    [44] => EmptyIterator

    [45] => RecursiveTreeIterator

    [46] => ArrayObject

    [47] => ArrayIterator

    [48] => RecursiveArrayIterator

    [49] => SplFileInfo

    [50] => DirectoryIterator

    [51] => FilesystemIterator

    [52] => RecursiveDirectoryIterator

    [53] => GlobIterator

    [54] => SplFileObject

    [55] => SplTempFileObject

    [56] => SplDoublyLinkedList

    [57] => SplQueue

    [58] => SplStack

    [59] => SplHeap

    [60] => SplMinHeap

    [61] => SplMaxHeap

    [62] => SplPriorityQueue

    [63] => SplFixedArray

    [64] => SplObjectStorage

    [65] => MultipleIterator

    [66] => ReflectionException

    [67] => Reflection

    [68] => ReflectionFunctionAbstract

    [69] => ReflectionFunction

    [70] => ReflectionGenerator

    [71] => ReflectionParameter

    [72] => ReflectionType

    [73] => ReflectionMethod

    [74] => ReflectionClass

    [75] => ReflectionObject

    [76] => ReflectionProperty

    [77] => ReflectionExtension

    [78] => ReflectionZendExtension

    [79] => SessionHandler

    [80] => __PHP_Incomplete_Class

    [81] => php_user_filter

    [82] => Directory

    [83] => AssertionError

    [84] => ZipArchive

    [85] => LibXMLError

    [86] => DOMException

    [87] => DOMStringList

    [88] => DOMNameList

    [89] => DOMImplementationList

    [90] => DOMImplementationSource

    [91] => DOMImplementation

    [92] => DOMNode

    [93] => DOMNameSpaceNode

    [94] => DOMDocumentFragment

    [95] => DOMDocument

    [96] => DOMNodeList

    [97] => DOMNamedNodeMap

    [98] => DOMCharacterData

    [99] => DOMAttr

    [100] => DOMElement

    [101] => DOMText

    [102] => DOMComment

    [103] => DOMTypeinfo

    [104] => DOMUserDataHandler

    [105] => DOMDomError

    [106] => DOMErrorHandler

    [107] => DOMLocator

    [108] => DOMConfiguration

    [109] => DOMCdataSection

    [110] => DOMDocumentType

    [111] => DOMNotation

    [112] => DOMEntity

    [113] => DOMEntityReference

    [114] => DOMProcessingInstruction

    [115] => DOMStringExtend

    [116] => DOMXPath

    [117] => PDOException

    [118] => PDO

    [119] => PDOStatement

    [120] => PDORow

    [121] => SimpleXMLElement

    [122] => SimpleXMLIterator

    [123] => XMLReader

    [124] => XMLWriter

    [125] => PharException

    [126] => Phar

    [127] => PharData

    [128] => PharFileInfo

    [129] => CURLFile

    [130] => finfo

    [131] => MongoDB\Driver\Command

    [132] => MongoDB\Driver\Cursor

    [133] => MongoDB\Driver\CursorId

    [134] => MongoDB\Driver\Manager

    [135] => MongoDB\Driver\Query

    [136] => MongoDB\Driver\ReadConcern

    [137] => MongoDB\Driver\ReadPreference

    [138] => MongoDB\Driver\Server

    [139] => MongoDB\Driver\BulkWrite

    [140] => MongoDB\Driver\WriteConcern

    [141] => MongoDB\Driver\WriteConcernError

    [142] => MongoDB\Driver\WriteError

    [143] => MongoDB\Driver\WriteResult

    [144] => MongoDB\Driver\Exception\LogicException

    [145] => MongoDB\Driver\Exception\RuntimeException

    [146] => MongoDB\Driver\Exception\UnexpectedValueException

    [147] => MongoDB\Driver\Exception\InvalidArgumentException

    [148] => MongoDB\Driver\Exception\ConnectionException

    [149] => MongoDB\Driver\Exception\AuthenticationException

    [150] => MongoDB\Driver\Exception\SSLConnectionException

    [151] => MongoDB\Driver\Exception\WriteException

    [152] => MongoDB\Driver\Exception\BulkWriteException

    [153] => MongoDB\Driver\Exception\ExecutionTimeoutException

    [154] => MongoDB\Driver\Exception\ConnectionTimeoutException

    [155] => MongoDB\BSON\Binary

    [156] => MongoDB\BSON\Javascript

    [157] => MongoDB\BSON\MaxKey

    [158] => MongoDB\BSON\MinKey

    [159] => MongoDB\BSON\ObjectID

    [160] => MongoDB\BSON\Regex

    [161] => MongoDB\BSON\Timestamp

    [162] => MongoDB\BSON\UTCDateTime

    [163] => mysqli_sql_exception

    [164] => mysqli_driver

    [165] => mysqli

    [166] => mysqli_warning

    [167] => mysqli_result

    [168] => mysqli_stmt

    [169] => SoapClient

    [170] => SoapVar

    [171] => SoapServer

    [172] => SoapFault

    [173] => SoapParam

    [174] => SoapHeader

    [175] => SQLite3

    [176] => SQLite3Stmt

    [177] => SQLite3Result

    [178] => XSLTProcessor

)

原来MongoDB的类名变成了:

MongoDB\Driver\Manager

因此这样修改文件 :