使用CloseableHttpClient 用get请求去请求一个文件下载接口

可以使用 Apache 的 HttpClient 来实现。

以下是使用 CloseableHttpClient 发送 GET 请求并下载文件的示例代码：

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
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;

public class HttpClientExample {
    public static void main(String[] args) throws Exception {
        String url = "http://example.com/file/download?id=123";
        String filePath = "/path/to/file"; // 文件保存路径

        CloseableHttpClient httpclient = HttpClients.createDefault();
        HttpGet httpget = new HttpGet(url);
        CloseableHttpResponse response = httpclient.execute(httpget);

        try {
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                InputStream inputStream = entity.getContent();
                FileOutputStream outputStream = new FileOutputStream(new File(filePath));
                byte[] buffer = new byte[1024];
                int len = -1;
                while ((len = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, len);
                }
                outputStream.flush();
                outputStream.close();
            }
            EntityUtils.consume(entity);
        } finally {
            response.close();
        }
    }
}

以上代码使用 CloseableHttpClient 发送 GET 请求，获取接口返回的文件流，并将文件保存到指定路径。你可以根据实际情况修改请求 URL、文件保存路径等参数。