一个简单的web容器

Posted 2020-07-12

1.一个简单的web容器其实就是一个简单的socket类的服务端，然后通过浏览器访问，将请求的内容输出到页面。

2.示例：HttpServer.java

package com.diytomcat.http;

import java.net.Socket;
import java.net.UnknownHostException;

import java.net.ServerSocket;
import java.net.InetAddress;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;

public class HttpServer {

public static final String WEB_ROOT =
System.getProperty("user.dir") + File.separator + "WebContent";
private final int port = 8080;

public void accept() throws UnknownHostException, IOException{
ServerSocket serverSocket = new ServerSocket(port, 2, InetAddress.getByName("127.0.0.1"));

while(true){
    Socket socket = serverSocket.accept();
    InputStream in = socket.getInputStream();
    OutputStream out = socket.getOutputStream();
    PrintWriter writer = new PrintWriter(out);
    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
    byte[] bytes = new byte[1024];
    FileInputStream fis = null;
    try {
        File file = new File(HttpServer.WEB_ROOT, "/test.jsp");
        if (file.exists()) {
            fis = new FileInputStream(file);
            int ch = fis.read(bytes, 0, 1024);
            while (ch!=-1) {
                out.write(bytes, 0, ch);
                ch = fis.read(bytes, 0, 1024);
            }
       }
       else {
           // file not found
          String errorMessage = "HTTP/1.1 404 File Not Found\r\n" +
          "Content-Type: text/html\r\n" +
          "Content-Length: 23\r\n" +
          "\r\n" +
          "<h1>File Not Found</h1>";
          out.write(errorMessage.getBytes());
      }
}
catch (Exception e) {
     // thrown if cannot instantiate a File object
     System.out.println(e.toString() );
}
finally {
    if (fis!=null)
    fis.close();
}
 socket.close();
}

}

public void sendStaticResource() throws IOException {

}

public static void main(String[] args){
HttpServer server = new HttpServer();
try {
server.accept();
} catch (IOException e) {
e.printStackTrace();
}
}
}