JavaWeb~使用HttpServer和Html 实现登录界面并跳转到个人简历(体会Cookie的用途)

//解析url中的键值对

int pos = request.url.indexOf(“?”);

if (pos != -1) {

// 看看 url 中是否有 ? . 如果没有, 就说明不带参数, 也就不必解析了

// 此处的 parameters 是希望包含整个 参数 部分的内容

// pos 表示 ? 的下标

// /index.html?a=10&b=20

// parameters 的结果就相当于是 a=10&b=20

String parameters = request.url.substring(pos + 1);

// 切分的最终结果, key a, value 10; key b, value 20;

parseKV(parameters, request.parameters);

}

//解析headers

String line = “”;

while ((line = bufferedReader.readLine()) != null && line.length() != 0) {

String[] result = line.split(": ");

request.headers.put(result[0], result[1]);

}

//解析cookie

String cookie = request.headers.get(“Cookie”);

if (cookie != null) {

parseCookie(cookie, request.cookies);

}

//解析body

if (“POST”.equalsIgnoreCase(request.method)

|| “PUT”.equalsIgnoreCase(request.method)) {

//暂时只考虑这俩个方法的body

int length = Integer.parseInt(request.headers.get(“Content-Length”));

char[] buffer = new char[length];

int len = bufferedReader.read(buffer);

request.body = new String(buffer, 0, len);

parseKV(request.body, request.parameters);

}

}

return request;

}

private static void parseCookie(String cookie, Map cookies) {

//在这里解析键值对

//先按; 分割

//再按=分割

String[] kv = cookie.split("; ");

for (String s : kv

) {

String[] result = s.split(“=”);

cookies.put(result[0], result[1]);

}

}

private static void parseKV(String parameters, Map parameters1) {

//在这里解析键值对

//先按&分割

//再按=分割

String[] kv = parameters.split(“&”);

for (String s : kv

) {

String[] result = s.split(“=”);

parameters1.put(result[0], result[1]);

}

}

// 给这个类构造一些 getter 方法. (不要搞 setter).

// 请求对象的内容应该是从网络上解析来的. 用户不应该修改.

public String getMethod() {

return method;

}

public String getUrl() {

return url;

}

public String getVersion() {

return version;

}

public String getBody() {

return body;

}

public String getHeaders(String key) {

return headers.get(key);

}

// 此处的 getter 手动写, 自动生成的版本是直接得到整个 hash 表.

// 而我们需要的是根据 key 来获取值.

public String getCookie(String key) {

return cookies.get(key);

}

public String getPararmeters(String key) {

return parameters.get(key);

}

@Override

public String toString() {

return “HttpRequest{” +

“method '” + method + ‘’’ +

“, url '” + url + ‘’’ +

“, version '” + version + ‘’’ +

", headers " + headers +

", parameters " + parameters +

", cookies " + cookies +

“, body '” + body + ‘’’ +

‘}’;

}

}

[](()实现返回响应

=====================================================================

• 注释详解

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.util.HashMap;

import java.util.Map;

public class HttpRespond {

private String version = “HTTP/1.1”;

private int statue; // 状态码

private String message; // 状态码的描述信息

private Map headers = new HashMap<>();

private StringBuilder body = new StringBuilder(); // 方便一会进行拼接.

// 当代码需要把响应写回给客户端的时候, 就往这个 OutputStream 中写就好了

private OutputStream outputStream;

// 表示一个 HTTP 响应, 负责构造

// 进行序列化操作

public static HttpRespond build(OutputStream outputStream) {

HttpRespond respond = new HttpRespond();

respond.outputStream = outputStream;

// 除了 outputStream 之外, 其他的属性的内容, 暂时都无法确定. 要根据代码的具体业务逻辑

// 来确定. (服务器的 “根据请求并计算响应” 阶段来进行设置的)

return respond;

}

public void setVersion(String version) {

this.version = version;

}

public void setStatue(int statue) {

this.statue = statue;

}

public void setMessage(String message) {

this.message = message;

}

public void setHeaders(String key, String value) {

this.headers.put(key, value);

}

public void setBody(String body) {

this.body.append(body);

}

// 以上的设置属性的操作都是在内存中倒腾.

// 还需要一个专门的方法, 把这些属性 按照 HTTP 协议 都写到 socket 中.

public void flush() throws IOException {

BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream));

String firstLine = version + " " + statue + " " + message;

bufferedWriter.write(firstLine + “n”);

headers.put(“Content-Length”, body.toString().getBytes().length + “”);

for (Map.Entry entry : headers.entrySet()) {

bufferedWriter.write(entry.getKey() + ": " + entry.getValue() + “n”);

}

bufferedWriter.write(“n”);

bufferedWriter.write(body.toString() + “n”);

bufferedWriter.flush();

}

}

[](()实现Http Sever

===========================================================================

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.net.ServerSocket;

import java.net.Socket;

import java.util.HashMap;

import java.util.Map;

import java.util.UUID;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

public class HttpSeverV3 {

//设置一个静态内部类表示user

static class User {

public String username;

public String password;

public User(String username, String password) {

this.username = username;

this.password = password;

}

@Override

public String toString() {

return “User{” +

“username='” + username + ‘’’ +

“, password='” + password + ‘’’ +

‘}’;

}

}

private ServerSocket serverSocket;

// session 会话. 指的就是同一个用户的一组访问服务器的操作, 归类到一起, 就是一个会话.

// 记者来采访你, 记者问的问题就是一个请求, 你回答的内容, 就是一个响应. 一次采访过程中

// 涉及到很多问题和回答(请求和响应), 这一组问题和回答, 就可以称为是一个 “会话” (整个采访的过程)

// sessions 中就包含很多会话. (每个键值对就是一个会话)

private Map sessions = new HashMap<>();

public HttpSeverV3(int port) throws IOException {

this.serverSocket = new ServerSocket(port);

}

public void start() throws IOException {

System.out.println(“服务器启动”);

ExecutorService executorService = Executors.newCachedThreadPool();

while (true) {

Socket clientSocket = serverSocket.accept();

executorService.execute(new Runnable() {

@Override

public void run() {

process(clientSocket);

}

});

}

}

private void process(Socket clientSocket) {

try {

HttpRequest request = HttpRequest.build(clientSocket.getInputStream());

HttpRespond respond = HttpRespond.build(clientSocket.getOutputStream());

if (request.getMethod() != null) {

//判断请求是什么方法 不同方法不同处理

if (“GET”.equalsIgnoreCase(request.getMethod())) {

doGet(request, respond);

} else if (“POST”.equalsIgnoreCase(request.getMethod())) {

doPost(request, respond);

} else {

respond.setHeaders(“Content-type”, “text/html”);

respond.setStatue(404);

respond.setMessage(“No Found”);

respond.setBody(“

NULL”);

}

//写入

respond.flush();

}

} catch (IOException e) {

e.printStackTrace();

} finally {

try {

clientSocket.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

private void doPost(HttpRequest request, HttpRespond respond) throws IOException {

if (request.getUrl().startsWith(“/login”)) {

System.out.println(request);

//判断登录名和密码是否正确

String userName = request.getPararmeters(“username”);

String 《一线大厂Java面试题解析+后端开发学习笔记+最新架构讲解视频+实战项目源码讲义》无偿开源 威信搜索公众号【编程进阶路】 password = request.getPararmeters(“password”);

if (“123”.equals(userName) && “aaa”.equals(password)) {

//登录成功

respond.setStatue(200);

respond.setMessage(“OK”);

respond.setHeaders(“Content-type”, “text/html”);

//通过cookie让浏览器记住你

// 现有的对于登陆成功的处理. 给这次登陆的用户分配了一个 session

// (在 hash 中新增了一个键值对), key 是随机生成的. value 就是用户的身份信息

// 身份信息保存在服务器中, 此时也就不再有泄露的问题了

// 给浏览器返回的 Cookie 中只需要包含 sessionId 即可

String sessionId = UUID.randomUUID().toString();

sessions.put(sessionId, new User(userName, password));

respond.setHeaders(“Set-Cookie”, “sessionId=”+sessionId);

InputStream inputStream = HttpSeverV3.class.getClassLoader().getResourceAsStream(“LoginFinish.html”);

assert inputStream != null;

BufferedReader bufferedReader =new BufferedReader(new InputStreamReader(inputStream));

String line = null;

while ((line = bufferedReader.readLine()) != null) {

respond.setBody(line);

}

bufferedReader.close();

} else {

//登录失败

respond.setStatue(200);

respond.setMessage(“OK”);

respond.setHeaders(“Content-type”, “text/html”);

//登录失败应该让重写登录

InputStream inputStream = HttpSeverV3.class.getClassLoader().getResourceAsStream(“Test.html”);

assert inputStream != null;

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));

//按行读取写入到body中

String line = null;

while ((line = bufferedReader.readLine()) != null) {

respond.setBody(line);

}

bufferedReader.close();

}

}

}

private void doGet(HttpRequest request, HttpRespond respond) throws IOException {

//返回一个html文件

if (request.getUrl().startsWith(“/ok”)) {

System.out.println(request);

//查看浏览器中是否有cookie 并且根据sessionId得到的用户的密码正确

String sessionId = request.getCookie(“sessionId”);

User user = sessions.get(sessionId);

if (user != null && “123”.equals(user.username) && “aaa”.equals(user.password)) {

//说明此时登录的用户就是主人直接返回简历

respond.setStatue(200);

respond.setMessage(“OK”);

respond.setHeaders(“Content-type”, “text/html”);

InputStream inputStream = HttpSeverV3.class.getClassLoader().getResourceAsStream(“LoginFinish.html”);

assert inputStream != null;

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));

//按行读取写入到body中

String line = null;

while ((line = bufferedReader.readLine()) != null) {

respond.setBody(line);

}

bufferedReader.close();

} else {

respond.setHeaders(“Content-type”, “text/html”);

respond.setStatue(200);

respond.setMessage(“Ok”);

//在这里我们先获取类对象再获取类加载器 最后根据文件名在Resource目录中找到该文件 返回其InputStream对象

InputStream inputStream = HttpSeverV3.class.getClassLoader().getResourceAsStream(“Test.html”);

assert inputStream != null;

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));

//按行读取写入到body中

String line = null;

while ((line = bufferedReader.readLine()) != null) {

respond.setBody(line);

}

bufferedReader.close();

}

}

}