Handwritten a simple web server (B/S architecture)

涉及WebServer-related technologies

IO流、Socket网络编程、HTTP协议、文件、多线程（同时处理多个浏览器的请求）、List集合

1 webHow the application server works：

• 连接过程：WebThe connection established between the server and its browser,Determine whether the connection between the two is successful;If the user can find and open a virtual file socket,说明WebA connection is successfully established between the server and its browser.

• 请求过程：Web浏览器利用socketFiles make various requests to their servers.

• Get the address of the requested resource

• Make corresponding processing according to whether it is a static resource or a dynamic resource

• 响应过程:The request made during the request process is made by usingHTTP协议传输到Web服务器,Then perform task processing.

• 关闭连接:After the response process is complete,WebThe process by which a server disconnects from its browser.

2 代码展示

（1）Main类

package com.weh;
import com.weh.httpserver.MyHttpServer;
public class Main {
    
// 开启多线程
    public static void main(String[] args) {
    
        new Thread(new MyHttpServer()).start();
    }
}

（2）MyHttpServer类

package com.weh.httpserver;
import com.weh.response.MyResponse;
import com.weh.request.MyRequest;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
/* * 1.通过Runnable接口的实现类,来开启线程 * 2.Create and start the server * 3.Implement the connection communication between the server and the client * */
public class MyHttpServer implements Runnable{
    
    public static final int port = 8080;    //服务器端口号
    public static final String WEB_ROOT=System.getProperty("user.dir")+
            File.separator+ "webapps";      //The current file directory path of the server

    @Override
    public void run() {
    
        ServerSocket serverSocket=null;
        Socket socket;
        InputStream input=null;
        OutputStream output=null;
        try {
    
            System.out.println("Web服务器已开启");
            serverSocket = new ServerSocket(port); //Pass in the port number and create the server

        } catch (Exception e) {
    
            System.exit(0);
        }
        //The server communicates with the client browser
        while(true){
    
            try {
    
                socket=serverSocket.accept();//请求
                input=socket.getInputStream();//Get the information sent by the client
                output=socket.getOutputStream();
                MyRequest request=new MyRequest(input); //数据处理
                request.parse();
                MyResponse response=new MyResponse(output);
                response.setMyRequest(request);
                response.sendStaticResource();//发送
            } catch (Exception e) {
    
                e.printStackTrace();
                continue;
            }finally {
    
                // 释放资源
                release(input,output);
            }
        }
    }
// 释放资源
    public void release(InputStream inputStream,OutputStream outputStream){
    
        try {
    
            if(inputStream != null) {
    
                inputStream.close();
            }
            if(outputStream != null){
    
                outputStream.close();
            }
        } catch (IOException e) {
    
            e.printStackTrace();
        }
    }
}

（3）MyRequest类

package com.weh.request;

import java.io.InputStream;
/* * 自定义MyRequest类 * 1.It mainly processes the information sent by the client and outputs it * 2.Get the name of the file to which the client switches * */
public class MyRequest {
    
    private InputStream input;
    private String uri;

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

// 输出客户端发过来的信息
    public void parse(){
    
        StringBuffer request=new StringBuffer(2048);
        int len;
        byte[] buffer=new byte[2048];
        try {
    
            len=input.read(buffer);
        } catch (Exception e) {
    
            len=-1;
        }
        for(int j=0;j<len;j++){
    
            request.append((char)buffer[j]);
        }
        System.out.print(request.toString());
        parseUri(request.toString());
    }

// Get the switched filename
    public void parseUri(String srt){
    
        int index1,index2;
        index1=srt.indexOf(" ");
        if(index1!=-1){
    
            index2=srt.indexOf(" ",index1+1);
            if(index2>index1){
    
                setUri(srt.substring(index1+1,index2));
            }
        }
    }

    public void setUri(String uri) {
    
        this.uri = uri;
    }

    public String getUri(){
    
        return this.uri;
    }
}

（4）MyResponse类

package com.weh.response;
import com.weh.httpserver.MyHttpServer;
import com.weh.request.MyRequest;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.List;

/* * 自定义MyResponse类 * 1.向SocketThe result of writing the request to the browser to respond to the output stream * 2.Gets all files in the current directory and creates an array of file types * 3.Reading and forwarding of data * */
public class MyResponse {
    
    private static final int BUFFER_SIZE=1024;
    MyRequest request;
    OutputStream output;
    FileInputStream fis=null;
    PrintWriter printWriter =null;
    public MyResponse(OutputStream output){
    
        this.output=output;
    }
    public void setMyRequest(MyRequest request){
    
        this.request=request;
    }
    public void sendStaticResource()throws IOException{
    
        byte[] bytes=new byte[BUFFER_SIZE];
        try {
    
            printWriter = new PrintWriter(output); //创建缓冲字符输出流
            File file=new File(MyHttpServer.WEB_ROOT+request.getUri());
            if(file.exists()){
      //判断文件目录是否存在
                //向SocketThe result of writing the request to the browser to respond to the output stream
                printWriter.println("HTTP/1.1 200 OK");
                printWriter.println("Content-Type:text/html;charset=UTF-8");
                printWriter.println();
// 判断文件是否为普通文件
                if(file.isFile()){
    
                    fis=new FileInputStream(file.getPath());    //创建文件字节输入流
                    fis.read(bytes);  //read direct stream
                    printWriter.write(new String(bytes));
// Determines whether the file is a file directory
                }else if(file.isDirectory()){
    
                    List<File> list= Arrays.asList(new File(file.getPath()).listFiles());//Gets all files in the current directory and creates an array of file types
                    for(File filename : list){
    //数组遍历
                      if(filename.getName().indexOf(".htm")>0) {
    //判断是否含有.htm的字符的文件
                          printWriter.write("<li>");
                          printWriter.write("<a style='text-decoration:blink;' href='" +
                                  "./" + filename.getName() + "'>"
                                  + filename.getName() + "</a>");
                          printWriter.write("</li>");
                      }
                    }
                }
// 若该文件不存在,则输出信息 File Not Found
            }else{
    
                printWriter.println("HTTP/1.1 404 File Not Found");
                printWriter.println("Content-Type:text/html;charset=UTF-8");
                printWriter.println("Content-Length:23");
                printWriter.println();
                printWriter.write("<h1>File Not Found</h1>");
            }
            printWriter.flush();//不返回任何值,Only used to refresh the stream
        } catch (Exception e) {
    
            e.printStackTrace();
        }finally{
    
            if(printWriter!=null){
    
                printWriter.close();
            }
            if(output!=null){
    
                output.close();
            }
            if(fis!=null){
    
                fis.close();
            }
        }
    }
}

3项目的结构设计

4 效果展示