学习过tomat源码的人是否有尝试着手写一个简易版的tomcat的冲动呢？其实熟读了tomcat源码的人就应该知道tomcat只是一个强大的socket服务，废话不多说，下面直接贴代码；

一、启动socket监听

public class MyServer {
	public static void main(String[] args) throws IOException {
		// 服务端创建一个监听
        ServerSocket serverSocket = new ServerSocket(9000);
        while(true) {
        	// 监听客户端连接，这里我们暂时没有多线程
            Socket socket = serverSocket.accept();

            // 要想获取客户端发送过来的内容，就要得到 InputStream类 的输入流对象
            InputStream inputStream = socket.getInputStream();

            //==========使用我们自定义的http处理的相关类===========//
            Request request = new Request(inputStream);
            System.out.println(request.readHtml());

            // 要想给客户端发送数据，就要得到
            OutputStream outputStream = socket.getOutputStream();
            Response response = new Response(outputStream);
            response.writeHtml("this is server");

            // 关闭
            inputStream.close();
            outputStream.close();
            socket.close();
        }
        
    }
}

二、将socket的inputStream封装成Request

public class Request {
	// 用来保存输入流对象
    private InputStream inputStream;
    // 从输入流中每次读取的字节长度
    private int bufferLength = 1024;

    /**
     * 构造函数
     * @param inputStream 输入流对象
     */
    public Request(InputStream inputStream){
        this.inputStream = inputStream;
    }

    /**
     * 读取内容
     * @return 返回的是字符串
     * @throws IOException
     */
    public String readHtml() throws IOException {
        // 使用BufferedInputStream对象来读取
        BufferedInputStream bufferedInputStream = new BufferedInputStream(this.inputStream);
        // 每次读取1024字节
        byte[] buffer = new byte[this.bufferLength];

        // 字符串拼接对象
        StringBuilder stringBuilder = new StringBuilder();
        int length = 0;
        while (true){

            length = bufferedInputStream.read(buffer);

            // 把读取的字节转为String类型
            // 然后拼接成一个大的字符串
            stringBuilder.append(new String(buffer,0,length));

            if (length<=0 || length<this.bufferLength){
                break; // 如果没有读取到内容就跳出循环
            }


        }

        // 返回字符串内容
        return stringBuilder.toString();
    }
}

三、将socket的outputStream封装成Response

http的响应数据格式必须遵守http协议

public class Response {
	private OutputStream outputStream;

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

    public void writeHtml(String html) throws IOException{
        // 拼装http响应的数据格式
        html = "http/1.1 200 ok\n"
                +"\n\n"
                +html;


        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(this.outputStream);
        bufferedOutputStream.write(html.getBytes());
        bufferedOutputStream.close();
    }
}