java httpclient发送post请求

以下是Java HttpClient发送POST请求的示例代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
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.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

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

            // 构造POST请求参数
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("username", "testuser"));
            params.add(new BasicNameValuePair("password", "testpass"));
            httpPost.setEntity(new UrlEncodedFormEntity(params));

            // 发送POST请求
            HttpResponse response = httpClient.execute(httpPost);

            // 处理响应结果
            System.out.println("Response Code : " + response.getStatusLine().getStatusCode());
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                BufferedReader br = new BufferedReader(new InputStreamReader(entity.getContent()));
                String line = "";
                while ((line = br.readLine()) != null) {
                    System.out.println(line);
                }
            }
            EntityUtils.consume(entity);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpClient.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

该示例代码使用Apache HttpClient库发送POST请求，构造POST请求参数并设置到HttpEntity中，然后使用HttpClient.execute()方法发送请求并获取响应结果。最后使用EntityUtils.consume()方法释放资源。