httpclient表单提交的java代码

当使用HttpClient库进行表单提交时，你可以通过以下Java代码来实现：

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.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 java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class FormSubmitExample {
    public static void main(String[] args) {
        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpPost httpPost = new HttpPost("http://example.com/form"); // 替换为实际的URL
        
        // 设置表单数据
        List<NameValuePair> params = new ArrayList<>();
        params.add(new BasicNameValuePair("username", "John"));
        params.add(new BasicNameValuePair("password", "password123"));
        
        try {
            httpPost.setEntity(new UrlEncodedFormEntity(params));
            
            HttpResponse response = httpClient.execute(httpPost);
            BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            
            String line;
            StringBuilder result = new StringBuilder();
            while ((line = reader.readLine()) != null) {
                result.append(line);
            }
            
            System.out.println(result.toString());
            
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

在上面的代码中，我们首先创建一个HttpClient实例，并使用HttpPost类来发送POST请求。然后，我们设置了表单数据，将其转换为UrlEncodedFormEntity，并使用setEntity方法将其设置到HttpPost实例中。最后，我们执行POST请求，并读取响应的内容。

请确保将`http://example.com/form`替换为你要提交表单的实际URL，并根据需要修改表单字段和对应的值。还要处理可能会抛出的异常。