1.話不多說直接上代碼,直接運行main方法就可以啦，url是需要下載的文件地址同诫，1.jpg是你要保存到本地的文件名咙俩，E:\是你要保存的本地磁盤路徑向胡，

2.實現(xiàn)基本原理

<1>打開URL連接

<2>獲取輸入流矾湃，讀到一個字節(jié)數(shù)組中

<3>獲取文件輸出流亡脑，將字節(jié)數(shù)組寫入指定文件目錄中

<4>關(guān)閉流

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

public class Test {
    /**
     * 從網(wǎng)絡(luò)Url中下載文件
     *
     * @param urlStr
     * @param fileName
     * @param savePath
     * @throws IOException
     */
    public static String downLoadFromUrl(String urlStr, String fileName, String savePath) {
        try {

            URL url = new URL(urlStr);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            // 設(shè)置超時間為3秒
            conn.setConnectTimeout(3 * 1000);
            // 防止屏蔽程序抓取而返回403錯誤
            conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

            // 得到輸入流
            InputStream inputStream = conn.getInputStream();
            // 獲取字節(jié)數(shù)組
            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 "";

    }

    /**
     * 從輸入流中獲取字節(jié)數(shù)組
     *
     * @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();
    }


    public static void main(String[] args) {

        downLoadFromUrl("https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=3363295869,2467511306&fm=26&gp=0.jpg",
                "1.jpg","E:\\");
    }
}