java中wget下载

### 实现 Java 中的 wget 功能 为了在 Java 中实现类似于 `wget` 的文件下载功能，可以使用 `HttpURLConnection` 类来处理 HTTP 请求并保存响应的内容到本地文件。下面是一个完整的解决方案： #### 使用 HttpURLConnection 下载文件 ```java import java.io.*; import java.net.HttpURLConnection; import java.net.URL; public class WgetExample { public static void downloadFile(String fileURL, String saveDir) throws IOException { URL url = new URL(fileURL); HttpURLConnection httpConn = (HttpURLConnection) url.openConnection(); int responseCode = httpConn.getResponseCode(); // Check if the request was successful if (responseCode == HttpURLConnection.HTTP_OK) { InputStream inputStream = httpConn.getInputStream(); String fileName = ""; String disposition = httpConn.getHeaderField("Content-Disposition"); if (disposition != null) { // Extract filename from header field int index = disposition.indexOf("filename="); if (index > 0) { fileName = disposition.substring(index + 10, disposition.length() - 1); } } else { // Extract filename from URL fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1, fileURL.length()); } // Save to local directory OutputStream outputStream = new FileOutputStream(saveDir + File.separator + fileName); int bytesRead = -1; byte[] buffer = new byte[4096]; while ((bytesRead = inputStream.read(buffer)) != -1) { outputStream.write(buffer, 0, bytesRead); } outputStream.close(); inputStream.close(); System.out.println("Downloaded file: " + fileName); } else { System.out.println("No file to download. Server replied HTTP code: " + responseCode); } httpConn.disconnect(); } public static void main(String[] args) { try { String fileUrl = "http://example.com/file.zip"; // Replace with your actual URL here. String dirToSave = "/path/to/save/directory"; downloadFile(fileUrl, dirToSave); } catch (IOException e) { e.printStackTrace(); } } } ``` 这段代码展示了如何创建一个简单的命令行工具，在给定远程资源的位置时能够自动将其存储到指定位置[^1]。 对于更复杂的需求，比如支持断点续传、多线程下载等功能，则可能需要引入第三方库如 Apache HttpClient 或 OkHttp 来简化开发过程[^2]。