【手写Tomcat】6.实现自己定义的MyHttpResponse

迈不过友情╰ 2023-09-30 08:02 18阅读 0赞

在上一篇文章，我们已经实现了MyHttpResponse，这次，我们来实现MyHttpResponse，这个类就相对于tomcat里面的HttpServletResponse。

我们还是只实现几个常见功能,分别是

*   **setContentType(String type)**
 *   **setStatus(int status)**
 *   **write(String mess)**
 *   **setHeader(String s, String s1)**
 *   **sendRedirect(String s)**

--------------------

# 代码编写 #

>  **我们还是首先在MyHttpResponse接口中定义上面的几个接口**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16][]

>  **然后我们在具体的实现类里面对这些方法进行编写，我们先在实现类里面定义几个成员变量，方便于管理，并且给出一些默认值。**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 1][]

> **编写一个构造器，在创建这个类时就初始化OutputStream**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 2][]

>  **然后我们对接口中定义的方法进行实现，首先是setContentType方法**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_19_color_FFFFFF_t_70_g_se_x_16][]

>  **然后是setStatus方法**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 3][]

>  **setHeader方法**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 4][]

>  **write方法**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 5][]

>  **sendRedirect方法**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 6][]

>  **完整代码如下**

import java.io.IOException;
    import java.io.OutputStream;
    
    public class MyHttpResponseImpl implements MyHttpResponse{
        private String responseRow = "HTTP/1.1 ";
        private String contentType = "Content-Type: text/html;charset=utf-8\r\n\r\n";
        private String responseHead = "";
        private OutputStream outputStream;
        private int status = 200;
    
        public MyHttpResponseImpl(OutputStream outputStream) {
            this.outputStream = outputStream;
        }
    
        @Override
        public void setContentType(String type) {
            contentType = "Content-Type:"+type+"\r\n\r\n";
        }
    
    
        @Override
        public void write(String mess){
            mess = responseRow+status+"\r\n"+responseHead+contentType+mess;
            try {
                outputStream.write(mess.getBytes());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        @Override
        public void setStatus(int status) {
            this.status = status;
        }
    
        @Override
        public void setHeader(String s, String s1) {
            String head = s+":"+s1+"\r\n";
            responseHead += head;
        }
    
        @Override
        public void sendRedirect(String s){
            setStatus(302);
            setHeader("location",s);
            write("");
        }
    }

--------------------

# 代码测试 #

> **我们创建一个简单的测试类来进行测试，具体就不说了，代码如下**

import com.clucky.myTomcat.myHttp.MyHttpResponse;
    import com.clucky.myTomcat.myHttp.MyHttpResponseImpl;
    
    import java.io.*;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class Test {
    
        public static void main(String[] args) {
            try {
                //得到ServerSocket，在8080端口进行监听
                ServerSocket serverSocket = new ServerSocket(8080);
                System.out.println("---------服务器启动成功----------");
                while (!serverSocket.isClosed()) {
                    //等待连接
                    Socket socket = serverSocket.accept();
                    System.out.println("连接成功.....");
                    OutputStream outputStream = socket.getOutputStream();
                    MyHttpResponse myHttpResponse = new MyHttpResponseImpl(outputStream);
                    myHttpResponse.write("测试成功.....");
                    System.out.println("断开连接.....");
                    //关闭流
                    socket.close();
                }
            } catch (IOException e) {
                System.out.println("服务器启动失败");
            }
        }
    }

--------------------

>  **我们首先测试是否能往游览器写数据，核心代码如下**

myHttpResponse.write("测试成功.....");

>  **启动程序，游览器进行访问，[http://localhost:8080/books][http_localhost_8080_books]，游览器成功输出，没有问题**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 7][]

--------------------

> **然后我们测试重定向，核心代码如下**

myHttpResponse.sendRedirect("https://www.baidu.com");

>  **访问前面的网址 ，[http://localhost:8080/books][http_localhost_8080_books]，发现跳转到了百度，测试成功**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 8][]

--------------------

> **测试状态码，核心代码如下，我们将状态码设置为404**

myHttpResponse.setStatus(404);
    myHttpResponse.write("");

>  **访问前面的网址 ，[http://localhost:8080/books][http_localhost_8080_books]，查看游览器状况以及抓包查看状态码，发现网页不能正常显示，并且抓包显示状态码为404，测试成功**

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 9][]

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 10][]

--------------------

>  **我们最后再来测试一些setContenType，setHeader我在这里就不测了。我们在setContentType中写入[MIME][]类型，application/x-tar，表示是一张图片，核心代码如下**

myHttpResponse.setContentType("application/x-tar");
    myHttpResponse.write("123");

> 我们还是在游览器中访问 [http://localhost:8080/books][http_localhost_8080_books]，发现一访问就下载了一个文件，我们也测试成功了

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 11][]

--------------------

## 到此，我们自己定义的MyHttpResponse也实现了，虽然功能不多，但是对于理解tomcat还是很有帮助，我们在后面的文章中将会慢慢实现其他的Servlet，最终实现一个相对完善的迷你tomcat，在这过程中更加深入的理解tomcat的运行机制。 ##

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[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 4]: https://img-blog.csdnimg.cn/d2eb478120e34811be1f352c1154bd33.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 5]: https://img-blog.csdnimg.cn/9016bc1759424f248da34c885740aa37.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 6]: https://img-blog.csdnimg.cn/b37b368baf994b79b7ea86c9acdeb401.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0,size_20,color_FFFFFF,t_70,g_se,x_16
[http_localhost_8080_books]: http://localhost:8080/books
[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0_size_20_color_FFFFFF_t_70_g_se_x_16 7]: https://img-blog.csdnimg.cn/add03f5bbf2a47218ae9c520decdd6e5.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5LiN5pyN6L6T55qE5bCR5bm0,size_20,color_FFFFFF,t_70,g_se,x_16
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[MIME]: https://blog.csdn.net/m0_51545690/article/details/123100441
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