详解GET方法：HttpURLConnection从网络获取资源

青旅半醒 2024-02-17 17:53 45阅读 0赞

import java.io.File;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.InputStream;  
import java.net.HttpURLConnection;  
import java.net.MalformedURLException;  
import java.net.URL;  
  
/\*\*

\* 客户端程序：用于根据指定的网址。访问网络的数据

**// 拿获取百度服务器端的logo图片为例**

\*  
\* @author Administrator  
\*  
\*/  
public class Demo01\_HttpURLConnection \{  
  
public static void main(String\[\] args) \{  
FileOutputStream fos = null;  
  
**// step1:先获取网络地址**  
String baseUrl = "https://www.baidu.com/img/bd\_logo1.png";  
 **// step2:根据网址，构建URL对象。用于打开和该网址指向的资源，建立连接**  
try \{  
URL url = new URL(baseUrl);  
 **// step3:根据url，打开连接**  
HttpURLConnection connection = (HttpURLConnection) url.openConnection();  
 **// step4:设置本次网络请求的参数**  
 **// 设置请求方式**  
connection.setRequestMethod("GET");// 该方法的参数：所有的参数字母全部大写。  
 **// 设置连接超时**  
connection.setConnectTimeout(5000);  
 **// step5:开始连接**  
connection.connect();// 该行代码可以省略  
 **// step6:获取服务端的响应码**  
int responseCode = connection.getResponseCode();  
System.out.println(responseCode);  
  
if (responseCode == HttpURLConnection.HTTP\_OK) \{// 200  
 **// step7:获取流，读数据**  
InputStream inputStream = connection.getInputStream();  
String fileName = baseUrl.substring(baseUrl.lastIndexOf("/") + 1);  
File file = new File("D:\\\\Ruby\\\\pro", fileName);  
fos = new FileOutputStream(file);  
byte\[\] bs = new byte\[1024\];  
int len = 0;  
while ((len = inputStream.read(bs)) != -1) \{  
fos.write(bs, 0, len);  
\}  
System.out.println("图片下载完毕。。。");  
\}  
  
// connection.disconnect();  
\} catch (MalformedURLException e) \{  
e.printStackTrace();  
\} catch (IOException e) \{  
e.printStackTrace();  
\} finally \{  
if (fos != null) \{  
try \{  
fos.close();  
\} catch (IOException e) \{  
e.printStackTrace();  
\}  
\}  
\}  
  
\}  
  
\}  
  
GitHub: https://github.com/HuaDanJson