Question

我用NodeJS（但没有Express）制作了自己的http服务器，并且遇到了一个普遍的问题：“所请求的资源上没有'Access-Control-Allow-Origin'标头。来源'http://192.168.0.103:8080'因此，在使用XHR从url获取文件时，“不允许访问”。我的http服务器文件如下：

#!/usr/bin/env node

'use strict';

var colors     = require('colors/safe'),
    os         = require('os'),
    httpServer = require('../lib/http-server'),
    portfinder = require('portfinder'),
    opener     = require('opener'),
    argv       = require('optimist')
      .boolean('cors')
      .argv;

var ifaces = os.networkInterfaces();

if (argv.h || argv.help) {
  console.log([
    'usage: http-server [path] [options]',
    '',
    'options:',
    '  -p           Port to use [8080]',
    '  -a           Address to use [0.0.0.0]',
    '  -d           Show directory listings [true]',
    '  -i           Display autoIndex [true]',
    '  -g --gzip    Serve gzip files when possible [false]',
    '  -e --ext     Default file extension if none supplied [none]',
    '  -s --silent  Suppress log messages from output',
    '  --cors[=headers]   Enable CORS via the "Access-Control-Allow-Origin" header',
    '                     Optionally provide CORS headers list separated by commas',
    '  -o [path]    Open browser window after starting the server',
    '  -c           Cache time (max-age) in seconds [3600], e.g. -c10 for 10 seconds.',
    '               To disable caching, use -c-1.',
    '  -U --utc     Use UTC time format in log messages.',
    '',
    '  -P --proxy   Fallback proxy if the request cannot be resolved. e.g.: http://someurl.com',
    '',
    '  -S --ssl     Enable https.',
    '  -C --cert    Path to ssl cert file (default: cert.pem).',
    '  -K --key     Path to ssl key file (default: key.pem).',
    '',
    '  -r --robots  Respond to /robots.txt [User-agent: *\\nDisallow: /]',
    '  --no-dotfiles  Do not show dotfiles',
    '  -h --help    Print this list and exit.'
  ].join('\n'));
  process.exit();
}

var port = argv.p || parseInt(process.env.PORT, 10),
    host = argv.a || '0.0.0.0',
    ssl = !!argv.S || !!argv.ssl,
    proxy = argv.P || argv.proxy,
    utc = argv.U || argv.utc,
    logger;

if (!argv.s && !argv.silent) {
  logger = {
    info: console.log,
    request: function (req, res, error) {
      var date = utc ? new Date().toUTCString() : new Date();
      if (error) {
        logger.info(
          '[%s] "%s %s" Error (%s): "%s"',
          date, colors.red(req.method), colors.red(req.url),
          colors.red(error.status.toString()), colors.red(error.message)
        );
      }
      else {
        logger.info(
          '[%s] "%s %s" "%s"',
          date, colors.cyan(req.method), colors.cyan(req.url),
          req.headers['user-agent']
        );
      }
    }
  };
}
else if (colors) {
  logger = {
    info: function () {},
    request: function () {}
  };
}

if (!port) {
  portfinder.basePort = 8080;
  portfinder.getPort(function (err, port) {
    if (err) { throw err; }
    listen(port);
  });
}
else {
  listen(port);
}

function listen(port) {
  var options = {
    root: argv._[0],
    cache: argv.c,
    showDir: argv.d,
    autoIndex: argv.i,
    gzip: argv.g || argv.gzip,
    robots: argv.r || argv.robots,
    ext: argv.e || argv.ext,
    logFn: logger.request,
    proxy: proxy,
    showDotfiles: argv.dotfiles
  };

  if (argv.cors) {
    options.cors = true;
    if (typeof argv.cors === 'string') {
      options.corsHeaders = argv.cors;
    }
  }

  if (ssl) {
    options.https = {
      cert: argv.C || argv.cert || 'cert.pem',
      key: argv.K || argv.key || 'key.pem'
    };
  }

  var server = httpServer.createServer(options);
  server.listen(port, host, function () {
    var canonicalHost = host === '0.0.0.0' ? '127.0.0.1' : host,
        protocol      = ssl ? 'https://' : 'http://';

    logger.info([colors.yellow('Starting up http-server, serving '),
      colors.cyan(server.root),
      ssl ? (colors.yellow(' through') + colors.cyan(' https')) : '',
      colors.yellow('\nAvailable on:')
    ].join(''));

    if (argv.a && host !== '0.0.0.0') {
      logger.info(('  ' + protocol + canonicalHost + ':' + colors.green(port.toString())));
    }
    else {
      Object.keys(ifaces).forEach(function (dev) {
        ifaces[dev].forEach(function (details) {
          if (details.family === 'IPv4') {
            logger.info(('  ' + protocol + details.address + ':' + colors.green(port.toString())));
          }
        });
      });
    }

    if (typeof proxy === 'string') {
      logger.info('Unhandled requests will be served from: ' + proxy);
    }

    logger.info('Hit CTRL-C to stop the server');
    if (argv.o) {
      opener(
        protocol + canonicalHost + ':' + port,
        { command: argv.o !== true ? argv.o : null }
      );
    }
  });
}

if (process.platform === 'win32') {
  require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
  }).on('SIGINT', function () {
    process.emit('SIGINT');
  });
}

process.on('SIGINT', function () {
  logger.info(colors.red('http-server stopped.'));
  process.exit();
});

process.on('SIGTERM', function () {
  logger.info(colors.red('http-server stopped.'));
  process.exit();
});

对我来说，最好的解决方案是在Javascript文件中添加一些智能语句，但在极端情况下，我将修改httpserver文件。

  var getJSON = function(url, callback) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, true);
     xhr.responseType = 'json';
    xhr.onload = function() {
      var status = xhr.status;
      if (status === 200) {
        callback(null, xhr.response);
      } else {
        callback(status, xhr.response);
      }
    };
    xhr.send();
};

app_firebase.storage().ref('X.json').getDownloadURL().then(function
（URL）{ getJSON（url，函数（错误，数据）{ console.log（“ fg”）; if（err！== null）{ alert（'出事了：'+ err）; }其他{ console.log（data）; } }）; }）;

谢谢！

Answer 1

这似乎是CORS的问题。您可能正在从另一个“来源”调用服务器（如果端口或协议不同，则认为来源也不同）。您需要将进行呼叫的来源添加到响应的Access-Control-Allow-Origin标头中。查看链接的文档，以进行更深入的讨论以及需要进行的操作。

具有NodeJ且错误号为'Access-Control-Allow-Origin'的标头的自身服务器

1 个答案: