用java写一个支持application/x-www-form-urlencoded请求并切参数类型可以自定义的工具类

好的，我可以帮您解答这个问题。您可以使用Java中的HttpURLConnection类来发送application/x-www-form-urlencoded请求，并设置请求的参数类型为自定义类型。以下是一个简单的工具类示例代码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.Map;

public class HttpUtils {
    public static String sendPostRequest(String url, Map<String, String> params, String contentType) throws IOException {
        URL requestUrl = new URL(url);
        HttpURLConnection connection = (HttpURLConnection) requestUrl.openConnection();
        connection.setRequestMethod("POST");
        connection.setDoOutput(true);
        connection.setRequestProperty("Content-Type", contentType);

        String query = "";
        for (Map.Entry<String, String> entry : params.entrySet()) {
            if (!query.isEmpty()) {
                query += "&";
            }
            query += URLEncoder.encode(entry.getKey(), "UTF-8") + "=" + URLEncoder.encode(entry.getValue(), "UTF-8");
        }

        byte[] postData = query.getBytes(StandardCharsets.UTF_8);
        connection.getOutputStream().write(postData);

        BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        StringBuilder response = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            response.append(line);
        }

        reader.close();
        connection.disconnect();

        return response.toString();
    }
}

您可以调用该类的sendPostRequest方法来发送请求，例如：

Map<String, String> params = new HashMap<>();
params.put("username", "john");
params.put("password", "password");

String response = HttpUtils.sendPostRequest("http://example.com/login", params, "application/x-www-form-urlencoded");

其中，第一个参数为请求的URL，第二个参数为请求的参数，第三个参数是Content-Type头部的值，这里设置为application/x-www-form-urlencoded。