java方法文件下载到本地磁盘

**Java 方法：从网络下载文件并保存到本地磁盘**

在 Java 中，下载文件并保存到本地磁盘是一个常见的需求。下面是使用 Java 的方法来实现这一点。

###1. 使用 `HttpURLConnection` 类首先，我们可以使用 `HttpURLConnection` 类来下载文件。这个类提供了一个简单的方式来连接 HTTP服务器，并从其上下载资源。

javaimport java.io.File;
import java.io.FileOutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class DownloadFile {
 public static void downloadFile(String url, String filePath) throws Exception {
 // 创建 URL 对象 URL fileUrl = new URL(url);

 // 打开 HTTP 连接 HttpURLConnection connection = (HttpURLConnection) fileUrl.openConnection();

 // 检查 HTTP 状态码 int responseCode = connection.getResponseCode();
 if (responseCode ==200) {
 // 获取文件大小 long fileSize = connection.getContentLengthLong();

 // 创建输出流 FileOutputStream outputStream = new FileOutputStream(filePath);

 // 下载文件 byte[] buffer = new byte[1024];
 int bytesRead;
 while ((bytesRead = connection.getInputStream().read(buffer)) != -1) {
 outputStream.write(buffer,0, bytesRead);
 }

 // 关闭输出流 outputStream.close();

 System.out.println("下载完成！文件大小：" + fileSize + "字节");
 } else {
 System.out.println("下载失败！");
 }
 }

 public static void main(String[] args) throws Exception {
 String url = " /> String filePath = "/path/to/downloaded/file.txt";

 downloadFile(url, filePath);
 }
}

javaimport ok />import ok />import ok />
public class DownloadFile {
 public static void downloadFile(String url, String filePath) throws Exception {
 // 创建 OkHttpClient 对象 OkHttpClient client = new OkHttpClient();

 // 创建 Request 对象 Request request = new Request.Builder()
 .url(url)
 .build();

 // 发送请求并获取响应 Response response = client.newCall(request).execute();

 // 检查 HTTP 状态码 if (response.code() ==200) {
 // 获取文件大小 long fileSize = response.body().contentLength();

 // 创建输出流 FileOutputStream outputStream = new FileOutputStream(filePath);

 // 下载文件 byte[] buffer = new byte[1024];
 int bytesRead;
 while ((bytesRead = response.body().byteStream().read(buffer)) != -1) {
 outputStream.write(buffer,0, bytesRead);
 }

 // 关闭输出流 outputStream.close();

 System.out.println("下载完成！文件大小：" + fileSize + "字节");
 } else {
 System.out.println("下载失败！");
 }
 }

 public static void main(String[] args) throws Exception {
 String url = " /> String filePath = "/path/to/downloaded/file.txt";

 downloadFile(url, filePath);
 }
}

javaimport org.apache. />import org.apache. />import org.apache. />import org.apache. />import org.apache. />
public class DownloadFile {
 public static void downloadFile(String url, String filePath) throws Exception {
 // 创建 HttpClient 对象 CloseableHttpClient client = HttpClients.createDefault();

 // 创建 GET 请求 HttpGet request = new HttpGet(url);

 // 发送请求并获取响应 HttpResponse response = client.execute(request);

 // 检查 HTTP 状态码 if (response.getStatusLine().getStatusCode() ==200) {
 // 获取文件大小 long fileSize = response.getEntity().getContentLength();

 // 创建输出流 FileOutputStream outputStream = new FileOutputStream(filePath);

 // 下载文件 byte[] buffer = new byte[1024];
 int bytesRead;
 while ((bytesRead = response.getEntity().getContent().read(buffer)) != -1) {
 outputStream.write(buffer,0, bytesRead);
 }

 // 关闭输出流 outputStream.close();

 System.out.println("下载完成！文件大小：" + fileSize + "字节");
 } else {
 System.out.println("下载失败！");
 }
 }

 public static void main(String[] args) throws Exception {
 String url = " /> String filePath = "/path/to/downloaded/file.txt";

 downloadFile(url, filePath);
 }
}