Java使用HttpClient實現文件下載

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;

@RestController
public class RequestController {
    @RequestMapping(path = "/download", method = RequestMethod.GET)
    public void downLoad(HttpServletResponse response, String fileName){
        File file = new File("E:/downloadRepository/" + fileName);
        try{
            InputStream inputStream = new BufferedInputStream (new FileInputStream(file));
            //創建緩沖區
            byte[] buffer = new byte[inputStream.available()];
            inputStream.read(buffer);
            inputStream.close();
            OutputStream outputStream = new BufferedOutputStream(response
                    .getOutputStream());
            outputStream.write(buffer);
            outputStream.flush();
            outputStream.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

import org.apache.commons.io.FileUtils;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import java.io.*;

public class RequestFileService {

    public void httpRequest(String fileName) {
            // 請求地址
            String url = "http://localhost:8080/download";
            // 下載文件保存路徑
            String savePath = "E:/demo/" + fileName;
            CloseableHttpClient httpclient = HttpClients.createDefault();
            CloseableHttpResponse response = null;
            try {
                // 使用URIBuilder對象用於設置請求參數
                URIBuilder urlBuilder = new URIBuilder(url);
                urlBuilder.addParameter("fileName", fileName);
                HttpGet httpGet = new HttpGet(urlBuilder.build());
                // 執行請求
                response = httpclient.execute(httpGet);
                if (response.getStatusLine().getStatusCode() == 200) {
                    String content = EntityUtils.toString(response.getEntity(), "UTF-8");
                    // 將請求內容轉換成文件並保存
                    FileUtils.writeStringToFile(new File(savePath), content, "UTF-8");
                }
            } catch (Exception e) {
                e.getStackTrace();
            }finally {
                try {
                    response.close();
                    httpclient.close();
                }catch (IOException e){
                    e.getStackTrace();
                }
            }
    }

    public static void main(String[] args) {
        RequestFileService requestFileService = new RequestFileService();
        //參數為請求文件名
        requestFileService.httpRequest("205老面館.txt");
    }
}