自己实现一个简单的支持并发的Web服务器

小鱼儿 2022-08-21 04:56 161阅读 0赞

前面我们自己实现了一个线程池，现在我们基于前面编写的线程池([http://blog.csdn.net/canot/article/details/50904001][http_blog.csdn.net_canot_article_details_50904001])编写一个支持并发访问的Web服务器来处理一些简单的HTTP请求/响应。

public class SimpleHttpServer {
        
        //定义处理HttpRequest的线程池 
        static ThreadPool<HttpRequestHandler> threadPool = new DefaultThreadPool<HttpRequestHandler>();
        static ServerSocket serverSocket;
        //该Web服务器的路径
        static String basePath;
        //默认的端口号
        static int port = 8080;
      //启动服务器
        public static void start() throws IOException {
            serverSocket = new ServerSocket(port);
            Socket client = null;
            //获取客户端的连接
            while ((client = serverSocket.accept()) != null) {
                //生成一个job放入线程池执行
                threadPool.execute(new HttpRequestHandler(client));
            }
            serverSocket.close();
        }
    
        static class HttpRequestHandler implements Runnable {
        
            private Socket client;
    
            public HttpRequestHandler(Socket client) {
                this.client = client;
            }
    
            public void run() {
                byte[] buff = new byte[1024];
                BufferedReader br = null;
                PrintWriter pw = null;
                File directory = new File("");
                String basePath = directory.getAbsolutePath();
                int length = 0;
                try {
                    //读取客户端发送的请求数据
                    br = new BufferedReader(new InputStreamReader(client.getInputStream()));
                    //获取请求行的第一行再解析出要请求的资源
                    String header = br.readLine();
                    String filePath = header.split(" ")[1];
                    //判断请求的资源的为html
                    if(filePath.endsWith("html")){
                    pw = new PrintWriter(client.getOutputStream());
                    //构造HTTP响应头信息
                    pw.println("HTTP/1.1 200 Ok");
                    pw.println("Server: wangxiServer");
                    pw.println("Content-Type: text/html;charset=UTF-8");
                    pw.println("");
                    //通过io流读取访问的资源，然后输出给客户端
                    InputStream is = new FileInputStream(new File(basePath,filePath));
                    while((length=is.read(buff))>0){
                        pw.println(new String(buff,0,length));
                    }
                    pw.flush();
                    //判断请求的资源的为jpg
                    }else if(filePath.endsWith("jpg")){
                        //获取要访问的图片流，把流的数据全部存在ByteArrayOutputStream中
                        ByteArrayOutputStream bos = new ByteArrayOutputStream();
                        InputStream is = new FileInputStream(new File(basePath,filePath));
                        while((length=is.read(buff))>0){
                            bos.write(buff, 0, length);
                        }
                        byte[] image  = bos.toByteArray();
                        //构造HTTP响应头,输出给客户端
                        pw = new PrintWriter(client.getOutputStream());
                        pw.println("HTTP/1.1 200 Ok");
                        pw.println("Server: wangxiServer");
                        pw.println("Content-Type: image/jpeg");
                        pw.println("Content-Length:"+image.length);
                        pw.println("");
                        //输出图片流
                        client.getOutputStream().write(image, 0, image.length);
                    }else{
                        pw.println("HTTP/1.1 200 Ok");
                        pw.println("Server: wangxiServer");
                        pw.println("Content-Type: text/html;charset=UTF-8");
                        pw.println("");
                        pw.println("404 No Found");
                        pw.flush();
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
    
            }
    
        }
    }

启动该服务器:

public class TestMyService {
    
        public static void main(String[] args) {
            try {
                SimpleHttpServer.start();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

SimpleHttpServer在建立起与客户端的连接之后，并不会直接处理客户端的请求，而是把其封装成HttpRequestHandler并交给线程池处理。在线程池中则由Worker处理客户端请求的同时，SimpleHttpServer能够继续完成后续客户端连接的建立，并不会阻塞后续客户端的请求。

在该项目的根目录下建立a.html,并放置图片1.jpg:

在浏览器中输入[http://localhost:8080/a.html][http_localhost_8080_a.html]可以看到图片正常显示，则完成了处理html和jpg的HTTP请求。

[http_blog.csdn.net_canot_article_details_50904001]: http://blog.csdn.net/canot/article/details/50904001
[http_localhost_8080_a.html]: http://localhost:8080/a.html