httpclient发送post请求并传送txt数据的工具类

以下是使用 Apache HttpClient 发送 POST 请求并传递 txt 数据的 Java 工具类示例：

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import org.apache.http.HttpEntity;
import org.apache.http.client.entity.EntityBuilder;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class HttpClientUtil {

  public static String sendPost(String url, String text) throws IOException {
    try (CloseableHttpClient client = HttpClients.createDefault()) {
      HttpPost httpPost = new HttpPost(url);
      HttpEntity entity = EntityBuilder.create().setText(text).build();
      httpPost.setEntity(entity);

      try (CloseableHttpResponse response = client.execute(httpPost)) {
        HttpEntity responseEntity = response.getEntity();
        if (responseEntity != null) {
          return EntityUtils.toString(responseEntity, StandardCharsets.UTF_8);
        }
      }
    }
    return null;
  }

}

其中 `url` 为请求地址，`text` 为要传递的文本数据。调用示例：

String response = HttpClientUtil.sendPost("http://example.com/api", "Hello, World!");

注意：发送请求时需要处理可能抛出的 `IOException` 异常。