node.js TypeError:路径必须是字符串。接收空

Question

我最近正在编写一个使用socket.io、node.js和express.js的javascript。这是服务器代码。

​

var
    port = +process.argv[2] || 8080,

    sanitizer = require('validator').sanitize,
    express = require('express'),

    server = express.createServer(),
    io = require('socket.io').listen(server),
    chat = io.of('/chat'),
    canvas = io.of('/canvas')
;

function sanitize(string) {
    return sanitizer(string).entityDecode()
}

server.listen(port);

server.get(/(^\/.*$)/, function(request, response) {
    var fileName = request.params[0];
    if (fileName == '/')
        fileName = '/index.html';
    response.sendfile(__dirname + '/client' + fileName);
});

io.sockets.on('connection', function(socket) {
    socket.on('setName', function (name) {
        name = sanitize(name);
        socket.set('name', name);
        socket.broadcast.emit('receive', {
            sender:'Server',
            message:name + ' has joined.'
        })
    });

    socket.on('send', function (message) {
        socket.get('name', function(error, name) {
            if (name)
                socket.broadcast.emit('receive', {
                    sender:name,
                    message:sanitize(message)
                })
        })
    });

    socket.on('draw', function (command) {
        io.sockets.emit('draw', command)
    });

    socket.on('updateCursor', function(position) {
        socket.get('name', function(error, name) {
            if (name)
                socket.broadcast.emit('updateCursor', {
                    name:name,
                    position:position
                });
        });
    });

    socket.on('disconnect', function() {
        socket.get('name', function(error, name) {
            if (name) {
                socket.broadcast.emit('receive', {
                    sender:'Server',
                    message:name + ' has left.'
                });
                socket.broadcast.emit('removeCursor', name);
            }
        })
    });
});

​

我能够成功地设置服务器，但是当我在浏览器上使用本地主机时，我会得到以下错误：

TypeError:路径必须是字符串。接收null at (C:\Users\Akshay\Desktop\whiteboard-master\whiteboard-master\node_modules\express\node_modules\connect\lib\middleware\static.js:127:20) at assertPath (path.js:8:11) at win32.连接(path.js:221:5) at exports.send path.js:221:5 at ServerResponse.res.sendfile186:3)在C:\Users\Akshay\Desktop\whiteboard-master\whiteboard-master\server.js:23:14 at callback (C:\Users\Akshay\Desktop\whiteboard-master\whiteboard-master\node_modules\express\lib\router\index.js:272:11) at param (C:\Users\Akshay\Desktop\whiteboard-master\whiteboard-master\node_modules\express\lib\router\index.js:246:11) at pass (C:\Users\Akshay\Desktop\whiteboard-master\whiteboard-master\node_modules\express\lib\router\index.js:253:5) at Router._dispatch (C:\Users\Akshay\Desktop\whiteboard-master\whiteboard-master\node_modules\express\lib\router\index.js:280:5) at Object.Router.middleware as handle

我使用不稳定的v0.5.8windows二进制节点版本开发了这个程序。但我目前正在运行4.4.5版本。

请帮帮我，我哪里出错了？

Answer 1

从您粘贴的示例代码中很难看出这一点，因为您的堆栈跟踪将index.js中的第45行引用为问题源(C:\Users\Akshay\Desktop\whiteboard-master\whiteboard-master\node_modules\express\lib\router\index.js:45:10)，但是当我查看IDE中的示例/粘贴代码时，它没有做任何事情。对sendfile的唯一调用(在堆栈跟踪中引用得更远)是在脚本的前面。

假设这是问题的位置，您应该console.log()或以其他方式调试要发送给访问者的路径/文件名的值。注意，在Windows中，路径分隔符是\而不是/。您应该使用path.join()来形成所服务文件的最终路径。ExpressJS示例说明了这一点：

app.get('/', function(req, res) {
    res.sendFile(path.join(__dirname, 'index.html'));
});