IT博客汇 | [原]《Swift入门》ubuntu下编译运行Swift开发的Web后端示例

[原]《Swift入门》ubuntu下编译运行Swift开发的Web后端示例

testcs_dn发表于 2016-05-08 12:56:18

这里只是演示如何在ubuntu下编译运行Swift开发的Web后端项目。

项目代码来自Bluemix上提供的示例代码，如果你有账号，可以去自己的空间下载，没有的话，可以通过下面的地址下载：

http://download.csdn.net/detail/testcs_dn/9513395

环境配置好之后，将下载的示例代码解压出来：

主要代码是“main.swift”，内容如下：

/**
 * Copyright IBM Corporation 2016
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

/**
* Creates a simple HTTP server that listens for incoming connections on port 9080.
* For each request receieved, the server simply sends a simple hello world message
* back to the client.
**/

#if os(Linux)
import Glibc
#else
import Darwin
#endif
import Utils
import Foundation

// Create server socket
let address = parseAddress()
let server_sockfd = createSocket(address)
// Listen on socket with queue of 5
listen(server_sockfd, 5)
var active_fd_set = fd_set()
print("Server is listening on port: \(address.port)\n")

// Initialize the set of active sockets
fdSet(server_sockfd, set: &active_fd_set)

let FD_SETSIZE = Int32(1024)

// Generate HTTP response
// Get environment variables
let environmentVars = NSProcessInfo.processInfo().environment
var responseBody = "<html><body>Hello from Swift on Linux!" +
  "<br />" +
  "<br />" +
  "<table border=\"1\">" +
  "<tr><th>Env Variable</th><th>Value</th></tr>"

for (variable, value) in environmentVars {
    responseBody += "<tr><td>\(variable)</td><td>\(value)</td></tr>\n"
}

responseBody += "</table></body></html>"

let httpResponse = "HTTP/1.0 200 OK\n" +
  "Content-Type: text/html\n" +
  "Content-Length: \(responseBody.length) \n\n" +
  responseBody

var clientname = sockaddr_in()
while true {
  // Block until input arrives on one or more active sockets
  var read_fd_set = active_fd_set;
  select(FD_SETSIZE, &read_fd_set, nil, nil, nil)
  // Service all the sockets with input pending
  for i in 0..<FD_SETSIZE {
    if fdIsSet(i,set: &read_fd_set) {
      if i == server_sockfd {
        // Connection request on original socket
        var size = sizeof(sockaddr_in)
        // Accept request and assign socket
        withUnsafeMutablePointers(&clientname, &size) { up1, up2 in
          var client_sockfd = accept(server_sockfd,
            UnsafeMutablePointer(up1),
            UnsafeMutablePointer(up2))
            print("Received connection request from client: " + String(inet_ntoa (clientname.sin_addr)) + ", port " + String(UInt16(clientname.sin_port).bigEndian))
            fdSet(client_sockfd, set: &active_fd_set)
        }
      }
      else {
        // Send HTTP response back to client
        write(i, httpResponse, httpResponse.characters.count)
        // Close client socket
        close(i)
        fdClr(i, set: &active_fd_set)
      }
    }
  }
}

可通过以下命令编译并启动服务：

root@ubuntu:/home/aven/swifttrans# swift build
root@ubuntu:/home/aven/swifttrans# .build/debug/Server
Server is listening on port: 9080

编译时，可能会出现以下错误：

error: unable to invoke subcommand: /usr/bin/swift-build (No such file or directory)

服务启动成功后，我们就可以通过浏览器访问了，结果如下图：