从零手写Tomcat【之】基础完善，接收与处理信息

• 1.启动服务，查看浏览器请求信息
• 2.获取客户端输出流，返回字符串信息给浏览器（失败与原因）
• 3.问题解决（响应行、响应头）
• 4.模拟返回 json 与 html
• 5.本章节源码
• 《目录：从零手写Tomcat》
• 《目录：Java设计模式》
• 《幕》

1.启动服务，查看浏览器请求信息

2.获取客户端输出流，返回字符串信息给浏览器（失败与原因）

package com.abl.tomcat;

import com.abl.tomcat.util.Log;
import com.abl.tomcat.util.Property;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Arrays;

/**
 * 程序启动入口
 */
public class Start {

    public static void main(String[] args) throws Exception {
        ServerSocket server = new ServerSocket(Property.getPort());
        Log.info("服务已经启动，端口号：" + Property.getPort() + "\n");

        Socket client = null;
        BufferedReader reader = null;
        PrintWriter writer = null;
        //循环监听
        while (true) {
            try {
                client = server.accept();
                reader = new BufferedReader(new InputStreamReader(client.getInputStream()));

                //读取请求地址
                String line = reader.readLine();
                String[] lines = line.split(" ");
                String requestMethod = lines[0];
                String requestURI = lines[1];
                Log.info("line : " + line);
                Log.info("lines : " + Arrays.asList(lines));
                Log.info("requestMethod : " + requestMethod);
                Log.info("requestURI : " + requestURI + "\n\n");

                //获取输出流，拼接返回信息
                //获取客户端输出流，返回字符串信息给浏览器
                writer = new PrintWriter(client.getOutputStream());
                StringBuilder responseStr = new StringBuilder();
                responseStr.append("404");
                writer.print(responseStr);
                writer.flush();
            } catch (Exception e) {
                e.printStackTrace();
            } finally {

                if (writer != null) {
                    try {
                        writer.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                if (reader != null) {
                    try {
                        reader.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                if (client != null) {
                    try {
                        client.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

            }
        }

    }

}

3.问题解决（响应行、响应头）

package com.abl.tomcat;

import com.abl.tomcat.util.Log;
import com.abl.tomcat.util.Property;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Arrays;

/**
 * 程序启动入口
 */
public class Start {

    public static void main(String[] args) throws Exception {
        ServerSocket server = new ServerSocket(Property.getPort());
        Log.info("服务已经启动，端口号：" + Property.getPort() + "\n");

        Socket client = null;
        BufferedReader reader = null;
        PrintWriter writer = null;
        //循环监听
        while (true) {
            try {
                client = server.accept();
                reader = new BufferedReader(new InputStreamReader(client.getInputStream()));

                //读取请求地址
                String line = reader.readLine();
                String[] lines = line.split(" ");
                String requestMethod = lines[0];
                String requestURI = lines[1];
                Log.info("line : " + line);
                Log.info("lines : " + Arrays.asList(lines));
                Log.info("requestMethod : " + requestMethod);
                Log.info("requestURI : " + requestURI + "\n\n");

                //获取输出流，拼接返回信息
                //获取客户端输出流，返回字符串信息给浏览器
                writer = new PrintWriter(client.getOutputStream());
                StringBuilder responseStr = new StringBuilder();
                responseStr.append("HTTP/1.1 200 OK\n");//响应行
                responseStr.append("content-type:text/html;charset=utf-8\n\n");//响应头
                responseStr.append("404");
                writer.print(responseStr);
                writer.flush();
            } catch (Exception e) {
                e.printStackTrace();
            } finally {

                if (writer != null) {
                    try {
                        writer.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                if (reader != null) {
                    try {
                        reader.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                if (client != null) {
                    try {
                        client.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

            }
        }

    }

}

4.模拟返回 json 与 html

package com.abl.tomcat;

import com.abl.tomcat.util.Log;
import com.abl.tomcat.util.Property;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Arrays;

/**
 * 程序启动入口
 */
public class Start {

    public static void main(String[] args) throws Exception {
        ServerSocket server = new ServerSocket(Property.getPort());
        Log.info("服务已经启动，端口号：" + Property.getPort() + "\n");

        Socket client = null;
        BufferedReader reader = null;
        PrintWriter writer = null;
        //循环监听
        while (true) {
            try {
                client = server.accept();

                reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
                writer = new PrintWriter(client.getOutputStream());

                //读取
                String line = reader.readLine();
                String[] lines = line.split(" ");
                String requestMethod = lines[0];
                String requestURI = lines[1];
                Log.info("line : " + line);
                Log.info("lines : " + Arrays.asList(lines));
                Log.info("requestMethod : " + requestMethod);
                Log.info("requestURI : " + requestURI + "\n\n");


                //获取输出流，拼接返回信息
                //返回请求信息
                StringBuilder responseStr = new StringBuilder();
                responseStr.append("HTTP/1.1 200 OK\n");//响应行
                if ("/".equals(requestURI)) {
                    //响应头+换行
                    responseStr.append("content-type:application/json;charset=utf-8\n\n");
                    //响应体
                    responseStr.append("{\"code\":200,\"desc\":\"请求成功，当前为根路径\",\"data\":null}");
                } else if ("/index".equals(requestURI)) {
                    //响应头+换行
                    responseStr.append("content-type:text/html;charset=utf-8\n\n");
                    //响应体
                    responseStr.append("<html>");
                    responseStr.append("<title>Abl Tomcat</title>");
                    responseStr.append("<h1> Hello </h1>");
                    responseStr.append("</html>");
                } else {
                    responseStr.append("content-type:text/html;charset=utf-8\n\n");
                    responseStr.append("404");//响应体
                }

                writer.print(responseStr);
                writer.flush();

            } catch (Exception e) {
                e.printStackTrace();
            } finally {

                if (writer != null) {
                    try {
                        writer.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                if (reader != null) {
                    try {
                        reader.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                if (client != null) {
                    try {
                        client.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }


            }
        }


    }

}

5.本章节源码

《目录：从零手写Tomcat》

《目录：Java设计模式》

《幕》