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[解決済み】Node.js Error: Cannot find module express

2021-12-29 04:27:48

質問

expressを使ってnode.jsサーバを起動しようとすると、エラーが発生します。

C:\ChatServer\Server>node server.js

module.js:340
    throw err;
          ^
Error: Cannot find module 'express'
    at Function.Module._resolveFilename (module.js:338:15)
    at Function.Module._load (module.js:280:25)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (C:\ChatServer\Server\server.js:6:9)
    at Object.<anonymous> (C:\ChatServer\Server\server.js:25:4)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)

でexpressをインストールしました。 -g :

C:\ChatServer\Server>npm install -g express
npm http GET https://registry.npmjs.org/express
npm http 304 https://registry.npmjs.org/express
npm http GET https://registry.npmjs.org/connect/2.7.11
npm http GET https://registry.npmjs.org/commander/0.6.1
npm http GET https://registry.npmjs.org/range-parser/0.0.4
npm http GET https://registry.npmjs.org/mkdirp/0.3.4
npm http GET https://registry.npmjs.org/cookie/0.1.0
npm http GET https://registry.npmjs.org/buffer-crc32/0.2.1
npm http GET https://registry.npmjs.org/fresh/0.1.0
npm http GET https://registry.npmjs.org/methods/0.0.1
npm http GET https://registry.npmjs.org/send/0.1.0
npm http GET https://registry.npmjs.org/cookie-signature/1.0.1
npm http GET https://registry.npmjs.org/debug
npm http 304 https://registry.npmjs.org/mkdirp/0.3.4
npm http 304 https://registry.npmjs.org/range-parser/0.0.4
npm http 304 https://registry.npmjs.org/cookie/0.1.0
npm http 304 https://registry.npmjs.org/connect/2.7.11
npm http 304 https://registry.npmjs.org/commander/0.6.1
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/buffer-crc32/0.2.1
npm http 304 https://registry.npmjs.org/fresh/0.1.0
npm http 304 https://registry.npmjs.org/methods/0.0.1
npm http 304 https://registry.npmjs.org/send/0.1.0
npm http 304 https://registry.npmjs.org/cookie-signature/1.0.1
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No readme data.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/debug
npm http GET https://registry.npmjs.org/mime/1.2.6
npm http GET https://registry.npmjs.org/qs/0.6.5
npm http GET https://registry.npmjs.org/send/0.1.1
npm http GET https://registry.npmjs.org/formidable/1.0.14
npm http GET https://registry.npmjs.org/cookie/0.0.5
npm http GET https://registry.npmjs.org/bytes/0.2.0
npm http GET https://registry.npmjs.org/pause/0.0.1
npm http 304 https://registry.npmjs.org/mime/1.2.6
npm http 304 https://registry.npmjs.org/bytes/0.2.0
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/pause/0.0.1
npm WARN package.json [email protected] No repository field.
npm http 304 https://registry.npmjs.org/formidable/1.0.14
npm http 304 https://registry.npmjs.org/qs/0.6.5
npm http 304 https://registry.npmjs.org/send/0.1.1
npm http 304 https://registry.npmjs.org/cookie/0.0.5
npm http GET https://registry.npmjs.org/mime
npm http 304 https://registry.npmjs.org/mime
C:\Users\Dmitry\AppData\Roaming\npm\express -> C:\Users\Dmitry\AppData\Roaming\npm\node_modules\express\bin\express
npm WARN package.json [email protected] 'repositories' (plural) Not supported.
npm WARN package.json Please pick one as the 'repository' field
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
[email protected] C:\Users\Dmitry\AppData\Roaming\npm\node_modules\express
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected] ([email protected])
└── [email protected] ([email protected], [email protected], [email protected], [email protected], [email protected], [email protected])

いくつかの情報

C:\ChatServer\Server>npm --version
1.2.24

C:\ChatServer\Server>node --version
v0.10.9

C:\ChatServer\Server>npm --version
1.2.24

C:\ChatServer\Server>npm ls -g installed express
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] 'repositories' (plural) Not supported.
npm WARN package.json Please pick one as the 'repository' field
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
npm WARN package.json [email protected] No repository field.
C:\Users\Dmitry\AppData\Roaming\npm
└── [email protected]


C:\ChatServer\Server>npm ls installed express
C:\ChatServer\Server
└── (empty)

解決方法は?

Express をアプリケーションのコンテキストにローカルにインストールする必要があります ( node_modules フォルダー)。

$ npm install express

この理由は、アプリケーションは常に自分のローカルコンテキストにある依存関係を探すからです。グローバルインストールは、ユニットテストランナーやブートストラッパーなど、システム全体で利用可能なバイナリをセットアップするためだけのものです。

Expressの場合、グローバルにインストールすると express バイナリで、アプリケーションをブートストラップすることができます。詳しくは、以下のように入力します。

$ express --help

では、最後の質問にお答えします。 はい を使用せずにインストールする必要があります。 -g .