java httpclient 代码

以下是使用Java HttpClient发送HTTP请求的示例代码：

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
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();
        HttpGet httpGet = new HttpGet("http://www.example.com");

        try (CloseableHttpResponse response = httpClient.execute(httpGet)) {
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                System.out.println(EntityUtils.toString(entity));
            }
        }
    }
}

使用HttpClient发送HTTP请求的基本步骤如下：

1. 创建一个 CloseableHttpClient 对象，通常使用 HttpClients.createDefault() 方法创建；
2. 创建一个 HttpGet 或者 HttpPost 对象，设置请求 URL 和请求参数；
3. 使用 CloseableHttpClient 对象执行请求，得到一个 CloseableHttpResponse 对象；
4. 从 CloseableHttpResponse 对象中获取响应内容。