java代码实现提交表单登录

在Java中，可以使用多种方式实现提交表单登录。以下是一种常见的实现方式：

1. 使用HttpClient库发送POST请求：

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class FormLoginExample {
    public static void main(String[] args) {
        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpPost httpPost = new HttpPost("http://example.com/login"); // 替换为实际的登录URL

        // 构造表单参数
        List<NameValuePair> params = new ArrayList<>();
        params.add(new BasicNameValuePair("username", "your_username")); // 替换为实际的用户名
        params.add(new BasicNameValuePair("password", "your_password")); // 替换为实际的密码

        try {
            httpPost.setEntity(new UrlEncodedFormEntity(params));

            HttpResponse response = httpClient.execute(httpPost);
            HttpEntity entity = response.getEntity();

            if (entity != null) {
                String responseText = EntityUtils.toString(entity);
                System.out.println(responseText);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

请注意，上述代码使用了Apache HttpClient库来发送HTTP请求，并使用`HttpPost`类来发送POST请求。你需要将`http://example.com/login`替换为实际的登录URL，以及将`your_username`和`your_password`替换为实际的用户名和密码。