使用Java实现一个最简单的Web ServerHello Web Server静态网页版参考资料

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我是靠谱客的博主友好唇膏，最近开发中收集的这篇文章主要介绍使用Java实现一个最简单的Web ServerHello Web Server静态网页版参考资料，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

Hello Web Server

Web Server没有你想象的那么难实现（当然要实现一个好的Java Web Server还是很有难度的）。你只要明白基本的HTTP协议，TCP编程和IO知识。当然，你也要会最简单的HTML代码。

我们先来一个屌丝版，这个屌丝版能显示Hello Web Server

package exec.network.webserver;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class SimpleHttpServer {
    private final static int TCP_PORT = 9090;

    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(TCP_PORT);
        Socket socket = ss.accept();
        BufferedReader br = new BufferedReader(
                new InputStreamReader(socket.getInputStream()));
        String buffer = null;
        while ((buffer = br.readLine()) != null && !s.equals("")) {
            System.out.println(buffer);
        }

        BufferedWriter bw = new BufferedWriter(
                new OutputStreamWriter(socket.getOutputStream()));
        bw.write("HTTP/1.1 200 OKn");
        bw.write("Content-Type: text/html; charset=UTF-8nn");
        bw.write("<html>n" + "<head>n" + "    <title>first page</title>n"
                + "</head>n" + "<body>n" + "    <h1>Hello Web Server!</h1>n"
                + "</body>n" + "</html>n");
        bw.flush();
        bw.close();

        br.close();
        socket.close();
        ss.close();
    }
}

运行这个程序，然后再浏览器里敲：http://localhost:9090/，页面上会出现一个大大的Hello Web Server。然后，就没有然后了……

静态网页版

看了上面的程序，你可能都会说，太屌丝了，不行，继续。

我们来加强这个Web Server。

准备示例的静态页面文件

准备一个webroot文件夹，里面放个index.htm文件，再准备一个01.jpg文件，作为图片放进去。这个是我们准备的index.htm，图片就不展示了。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
<h2>HTTP SERVER</h2>
<p>Where there is a will, there is a way.</p>
<img src="01.jpg"  />
</body>
</html>

准备HttpServer和Request，Response程序

HttpServer

package exec.network.webserver;

import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class HttpServer {
    private static final int SERVER_PORT = 9090;
    public static final String WEB_ROOT = System.getProperty("user.dir")
            + File.separator + "webroot";
    private static final String SHUTDOWN_COMMAND = "/QUIT";

    public static void main(String[] args) {
        HttpServer server = new HttpServer();
        server.await();
    }

    public void await() {
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(SERVER_PORT);
        }
        catch (Exception e) {
            e.printStackTrace();
            System.exit(1);
        }

        while(true) {
            Socket socket = null;
            InputStream input = null;
            OutputStream output = null;
            try {
                socket = serverSocket.accept();
                input = socket.getInputStream();
                output = socket.getOutputStream();

                // 创建Request对象并解析
                Request request = new Request(input);
                request.parse();
                // 检查是否是关闭服务命令
                if (request.getUri().equals(SHUTDOWN_COMMAND)) {
                    break;
                }

                // 创建 Response 对象
                Response response = new Response(output);
                response.setRequest(request);
                response.sendStaticResource();

                // 关闭 socket 对象
                socket.close();
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

Request

package exec.network.webserver;

import java.io.InputStream;

public class Request {
    private final static int BUFFER_SIZE = 1024;
    private InputStream input;
    private String uri;

    public Request(InputStream input) {
        this.input = input;
    }

    public void parse() {
        StringBuffer request = new StringBuffer();
        int readLength;
        byte[] buffer = new byte[BUFFER_SIZE];

        try {
            readLength = input.read(buffer);
        } catch (Exception e) {
            e.printStackTrace();
            readLength = -1;
        }
        for(int i = 0; i < readLength; i++) {
            request.append((char)buffer[i]);
        }
        System.out.print(request.toString());
        uri = parseUri(request.toString());
    }

    private String parseUri(String requestString) {
        int index1, index2;
        index1 = requestString.indexOf(' ');
        if (index1 != -1) {
            index2 = requestString.indexOf(' ', index1 + 1);
            if (index2 > index1)
                return requestString.substring(index1 + 1, index2);
        }
        return null;
    }

    public String getUri() {
        return uri;
    }
}

Response

package exec.network.webserver;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;

public class Response {
    private static final int BUFFER_SIZE = 1024;
    Request request;
    OutputStream output;

    public Response(OutputStream output) {
        this.output = output;
    }

    public void setRequest(Request request) {
        this.request = request;
    }

    public void sendStaticResource() throws IOException{
        byte[] buffer = new byte[BUFFER_SIZE];
        FileInputStream fis = null;
        try {            
            File file = new File(
                    HttpServer.WEB_ROOT, request.getUri());
            if(file.exists()) {
                output.write("HTTP/1.1 200 OKn".getBytes());
                output.write("Content-Type: text/html; charset=UTF-8nn".getBytes());
                fis = new FileInputStream(file);
                int readLength;
                while((readLength = fis.read(buffer, 0, BUFFER_SIZE)) > 0 ) {
                    output.write(buffer, 0, readLength);
                }
            }
            else {
                String errMsg = "HTTP/1.1 404 File Not Foundrn" + "Content-Type: text/htmlrn"
                        + "Content-Length: 23rn" + "rn" + "<h1>File Not Found</h1>";
                output.write(errMsg.getBytes());
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        finally {
            if(fis != null) {
                fis.close();
            }
        }
    }
}