写一篇Java基础代码

我可以给你一个简单的Java基础代码示例：public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World!");
}
}

相关问题

帮我写一篇java抢票代码

抢票代码存在一定的法律风险和道德风险，建议不要使用此类代码。如果您需要购买车票或其他票务，可以通过正常渠道购买或者使用官方提供的抢票工具。

同时，即便是想要编写抢票代码，也需要有一定的技术基础和对相关网站的了解。以下是一个简单的Java抢票代码示例，仅供参考。

import java.net.HttpURLConnection;
import java.net.URL;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.HashMap;
import java.util.Map;

public class GrabTicket {
    private static final String LOGIN_URL = "https://12306.cn/login";
    private static final String QUERY_URL = "https://12306.cn/query";
    private static final String BOOK_URL = "https://12306.cn/book";
    private static final String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36";

    private static Map<String, String> cookies = new HashMap<>();
    private static String token = "";

    public static void main(String[] args) throws Exception {
        // 登录
        login("username", "password");

        // 查询车票
        String trainInfo = query("fromStation", "toStation", "date");

        // 预订车票
        String result = book(trainInfo);

        System.out.println(result);
    }

    private static void login(String username, String password) throws Exception {
        URL url = new URL(LOGIN_URL);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();

        // 设置请求头
        conn.setRequestMethod("POST");
        conn.setRequestProperty("User-Agent", USER_AGENT);
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setDoOutput(true);

        // 设置请求体
        OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream());
        String data = "username=" + username + "&password=" + password;
        out.write(data);
        out.flush();
        out.close();

        // 获取响应头中的cookie
        String cookie = conn.getHeaderField("Set-Cookie");
        cookies.put("JSESSIONID", cookie.substring(0, cookie.indexOf(";")));

        // 获取响应体中的token
        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        while ((line = in.readLine()) != null) {
            if (line.contains("globalRepeatSubmitToken")) {
                token = line.substring(line.indexOf("'") + 1, line.lastIndexOf("'"));
                break;
            }
        }
        in.close();
    }

    private static String query(String fromStation, String toStation, String date) throws Exception {
        URL url = new URL(QUERY_URL);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();

        // 设置请求头
        conn.setRequestMethod("GET");
        conn.setRequestProperty("User-Agent", USER_AGENT);
        conn.setRequestProperty("Cookie", cookies.get("JSESSIONID"));

        // 设置请求参数
        String params = "?from_station=" + fromStation + "&to_station=" + toStation + "&date=" + date;
        conn.setDoOutput(true);
        OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream());
        out.write(params);
        out.flush();
        out.close();

        // 获取响应体
        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        StringBuilder result = new StringBuilder();
        while ((line = in.readLine()) != null) {
            result.append(line);
        }
        in.close();

        return result.toString();
    }

    private static String book(String trainInfo) throws Exception {
        URL url = new URL(BOOK_URL);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();

        // 设置请求头
        conn.setRequestMethod("POST");
        conn.setRequestProperty("User-Agent", USER_AGENT);
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setRequestProperty("Cookie", cookies.get("JSESSIONID"));

        // 设置请求体
        String data = "trainInfo=" + trainInfo + "&token=" + token;
        OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream());
        out.write(data);
        out.flush();
        out.close();

        // 获取响应体
        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        StringBuilder result = new StringBuilder();
        while ((line = in.readLine()) != null) {
            result.append(line);
        }
        in.close();

        return result.toString();
    }
}

需要注意的是，以上代码仅供参考。抢票代码可能存在许多问题，如网络延迟、验证码识别等，需要根据实际情况进行调整和优化。同时，使用抢票代码可能会对正常的购票流程造成干扰，甚至会导致购票失败。因此，建议遵守相关规定，通过正常渠道购买车票。

一篇Java基础总结文档

我很高兴能够为您提供一些关于Java基础的总结文档，Java是一种面向对象的编程语言，它是由Sun Microsystems在1995年发明的。Java基础知识包括基本语法，数据类型，控制结构，数组，方法，类和继承等。Java还具有平台无关性，这意味着编写的Java代码可以在多个操作系统上运行而不需要任何修改。如果您需要进一步了解Java，可以参考Oracle的Java官方文档。