httpclient发送post请求

使用Apache HttpClient发送POST请求的示例代码如下：

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import java.io.IOException;

public class HttpClientExample {

    public static void main(String[] args) throws IOException {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost("http://example.com/api/post");

        // 设置请求体
        String requestBody = "{\"name\": \"John\", \"age\": 30}";
        StringEntity entity = new StringEntity(requestBody, ContentType.APPLICATION_JSON);
        httpPost.setEntity(entity);

        // 发送请求
        CloseableHttpResponse response = httpClient.execute(httpPost);

        // 处理响应
        HttpEntity responseEntity = response.getEntity();
        if (responseEntity != null) {
            String responseBody = EntityUtils.toString(responseEntity);
            System.out.println(responseBody);
        }
        response.close();
        httpClient.close();
    }

}

在这个示例中，我们创建了一个默认的CloseableHttpClient实例，并设置POST请求的URL为http://example.com/api/post。我们使用StringEntity类来设置请求体，这个请求体是一个JSON字符串。最后，我们执行POST请求并处理响应。