java httpclient发送post请求

好的，下面是Java HttpClient发送POST请求的示例代码：

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

import java.io.IOException;

public class HttpClientExample {

    public static void main(String[] args) {
        HttpClient httpClient = HttpClientBuilder.create().build();

        try {
            HttpPost request = new HttpPost("http://www.example.com/api");
            String requestBody = "{\"param1\": \"value1\", \"param2\": \"value2\"}";
            StringEntity params = new StringEntity(requestBody);
            request.addHeader("content-type", "application/json");
            request.setEntity(params);

            HttpResponse response = httpClient.execute(request);
            HttpEntity entity = response.getEntity();
            String responseBody = EntityUtils.toString(entity);

            System.out.println(responseBody);
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}

在上面的代码中，我们首先创建了一个 HttpClient 对象。然后，我们创建了一个 HttpPost 对象，并设置了请求的 URL。接下来，我们设置了请求体，即要发送的数据。在这个例子中，我们使用 JSON 格式发送数据。接着，我们设置了请求头，指定了请求体的类型。最后，我们执行请求，并从响应中读取数据。注意，我们使用 HttpEntityUtils 工具类将响应实体转换为字符串。