1.FileUtils.copyURLToFile实现：
import java.io.File;
import java.net.URL;
import org.apache.commons.io.FileUtils; public class DownLoadFile { /**
* 网络文件下载保存
* @param url 文件url
* @param dir 存储目录
* @param fileName 存储文件名
*/
public static void downloadHttpUrl(String url, String dir, String fileName) {
try {
URL httpurl = new URL(url);
File dirfile = new File(dir);
if (!dirfile.exists()) {
dirfile.mkdirs();
}
FileUtils.copyURLToFile(httpurl, new File(dir+fileName));
} catch (Exception e) {
e.printStackTrace();
}
} /**
* 测试
* @param args
*/
public static void main(String[] args) {
downloadHttpUrl("http://gtms03.alicdn.com/tps/i3/TB1VF6uGFXXXXalaXXXmh5R_VXX-237-236.png", "D:/download/", "1.png");
}
}
图示：
2.常规写法：
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL; public class DownLoadFile { /**
* 从网络Url中下载文件
*
* @param urlstr 文件url
* @param fileName 存储文件名
* @param savePath 存储路径
* @throws IOException
*/
public static String downLoadFromUrl(String urlStr, String fileName, String savePath) {
try { URL url = new URL(urlStr);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// 设置超时间为3秒
conn.setConnectTimeout(3 * 1000);
// 防止屏蔽程序抓取而返回403错误
conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)"); // 得到输入流
InputStream inputStream = conn.getInputStream();
// 获取自己数组
byte[] getData = readInputStream(inputStream); // 文件保存位置
File saveDir = new File(savePath);
if (!saveDir.exists()) {
saveDir.mkdir();
}
File file = new File(saveDir + File.separator + fileName);
FileOutputStream fos = new FileOutputStream(file);
fos.write(getData);
if (fos != null) {
fos.close();
}
if (inputStream != null) {
inputStream.close();
}
// System.out.println("info:"+url+" download success");
return saveDir + File.separator + fileName;
} catch (Exception e) {
e.printStackTrace();
}
return ""; } /**
* 从输入流中获取字节数组
*
* @param inputStream
* @return
* @throws IOException
*/
public static byte[] readInputStream(InputStream inputStream) throws IOException {
byte[] buffer = new byte[1024];
int len = 0;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
while ((len = inputStream.read(buffer)) != -1) {
bos.write(buffer, 0, len);
}
bos.close();
return bos.toByteArray();
} /**
* 测试
* @param args
*/
public static void main(String[] args) {
downLoadFromUrl("http://gtms03.alicdn.com/tps/i3/TB1VF6uGFXXXXalaXXXmh5R_VXX-237-236.png", "2.png", "D:/download/");
} }
图示：