针对谷歌浏览器中，点击图片超链接实现下载而不是预览，解决办法

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针对某些浏览器,比如谷歌浏览器，在超链接a标签中给出图片url，点击a标签不是期望的下载而是预览，采用以下办法可以解决。 

 //图片url
        imgDownload: function (url, filename) {
            var browserIsIe = this.browserIsIe();

            if (browserIsIe) {
                var save_link = document.createElementNS('http://www.w3/1999/xhtml', 'a');
                save_link.href = url;
                save_link.download = filename;
                var event = document.createEvent('MouseEvents');
                event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
                save_link.dispatchEvent(event);
            } else {
                window.location.href = CONTEXT_PATH + "/api/qyda/qyxx/downLoadQyxxPic?dataUrl=" + url + "&fileName=" + filename;
            }
        },

        //判断是否为Trident内核浏览器(IE等)函数
        browserIsIe: function () {
            if (!!window.ActiveXObject || "ActiveXObject" in window) {
                return true;
            }
            else {
                return false;
            }
        }

 @RequestMapping(value = "downLoadQyxxPic")
    public void downloadFile(HttpServletRequest request, HttpServletResponse response,
                             @RequestParam(value = "dataUrl") String dataUrl,
                             @RequestParam(value = "fileName") String fileName) throws IOException {
        URL url = null;

        InputStream is = null;

        ByteArrayOutputStream outStream = null;
        OutputStream outputStream = null;
        HttpURLConnection httpUrl = null;
        try {
            response.setContentType("multipart/form-data");
            response.setHeader("Content-Disposition","attachment; filename = "+ URLEncoder.encode(fileName,"utf-8"));
            outputStream = response.getOutputStream();
            url = new URL(dataUrl);

            httpUrl = (HttpURLConnection) url.openConnection();

            httpUrl.connect();

            httpUrl.getInputStream();

            is = httpUrl.getInputStream();


            outStream = new ByteArrayOutputStream();

            //创建一个Buffer字符串

            byte[] buffer = new byte[1024];

            //每次读取的字符串长度，如果为-1，代表全部读取完毕

            int len = 0;

            //使用一个输入流从buffer里把数据读取出来

            while ((len = is.read(buffer)) != -1) {

                //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度

                outStream.write(buffer, 0, len);
                outputStream.write(buffer,0, len);
            }

        } catch (Exception e) {

            e.printStackTrace();

        } finally {
            outputStream.close();
            if (is != null)

            {

                try {

                    is.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

            if (outStream != null)

            {

                try {

                    outStream.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

            if (httpUrl != null)

            {

                httpUrl.disconnect();

            }

        }

    }

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.imageio.stream.FileImageInputStream;
import org.springframework.stereotype.Component;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
@Component
public class Base64Util{
    /**
     * 字符串转图片
     * @param base64Str
     * @return
     */
    public static byte[] decode(String base64Str){
        byte[] b = null;
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            b = decoder.decodeBuffer(replaceEnter(base64Str));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return b;
    }

    /**
     * 图片转字符串
     * @param image
     * @return
     */
    public static String encode(byte[] image){
        BASE64Encoder decoder = new BASE64Encoder();
        return replaceEnter(decoder.encode(image));
    }

    public static String encode(String uri){
        BASE64Encoder encoder = new BASE64Encoder();
        return replaceEnter(encoder.encode(uri.getBytes()));
    }

    /**
     *
     * @path    图片路径
     * @return
     */

    public static byte[] imageTobyte(String path){
        byte[] data = null;
        FileImageInputStream input = null;
        try {
            input = new FileImageInputStream(new File(path));
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            byte[] buf = new byte[1024];
            int numBytesRead = 0;
            while((numBytesRead = input.read(buf)) != -1){
                output.write(buf, 0, numBytesRead);
            }
            data = output.toByteArray();
            output.close();
            input.close();

        } catch (Exception e) {
            e.printStackTrace();
        }

        return data;
    }



    public static String replaceEnter(String str){
        String reg ="[\n-\r]";
        Pattern p = Patternpile(reg);
        Matcher m = p.matcher(str);
        return m.replaceAll("");
    }


}

import org.springframework.stereotype.Component;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import java.awt.Graphics;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.Transparency;
import java.HttpURLConnection;
import java.URL;

@Component
public class ImageUtils {

    public static String getBase64ByImgUrl(String url) {
        String suffix = url.substring(url.lastIndexOf(".") + 1);
        try {
            URL urls = new URL(url);
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            Image image = Toolkit.getDefaultToolkit().getImage(urls);
            BufferedImage biOut = toBufferedImage(image);
            ImageIO.write(biOut, suffix, baos);
            String base64Str = Base64Util.encode(baos.toByteArray());
            return base64Str;
        } catch (Exception e) {
            return "";
        }

    }

    public static BufferedImage toBufferedImage(Image image) {
        if (image instanceof BufferedImage) {
            return (BufferedImage) image;
        }
        // This code ensures that all the pixels in the image are loaded
        image = new ImageIcon(image).getImage();
        BufferedImage bimage = null;
        GraphicsEnvironment ge = GraphicsEnvironment
                .getLocalGraphicsEnvironment();
        try {
            int transparency = Transparency.OPAQUE;
            GraphicsDevice gs = ge.getDefaultScreenDevice();
            GraphicsConfiguration gc = gs.getDefaultConfiguration();
            bimage = gc.createCompatibleImage(image.getWidth(null),
                    image.getHeight(null), transparency);
        } catch (HeadlessException e) {
            // The system does not have a screen
        }
        if (bimage == null) {
            // Create a buffered image using the default color model
            int type = BufferedImage.TYPE_INT_RGB;
            bimage = new BufferedImage(image.getWidth(null),
                    image.getHeight(null), type);
        }
        // Copy image to buffered image
        Graphics g = bimage.createGraphics();
        // Paint the image onto the buffered image
        g.drawImage(image, 0, 0, null);
        g.dispose();
        return bimage;
    }

    /**
     * 通过图片的url获取图片的base64字符串
     *
     * @param imgUrl 图片url
     * @return 返回图片base64的字符串
     */
    public static String image2Base64(String imgUrl) {

        URL url = null;

        InputStream is = null;

        ByteArrayOutputStream outStream = null;

        HttpURLConnection httpUrl = null;

        try {

            url = new URL(imgUrl);

            httpUrl = (HttpURLConnection) url.openConnection();

            httpUrl.connect();

            httpUrl.getInputStream();

            is = httpUrl.getInputStream();


            outStream = new ByteArrayOutputStream();

            //创建一个Buffer字符串

            byte[] buffer = new byte[1024];

            //每次读取的字符串长度，如果为-1，代表全部读取完毕

            int len = 0;

            //使用一个输入流从buffer里把数据读取出来

            while ((len = is.read(buffer)) != -1) {

                //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度

                outStream.write(buffer, 0, len);

            }

            // 对字节数组Base64编码

            return Base64Util.encode(outStream.toByteArray());

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            if (is != null)

            {

                try {

                    is.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

            if (outStream != null)

            {

                try {

                    outStream.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

            if (httpUrl != null)

            {

                httpUrl.disconnect();

            }

        }

        return imgUrl;

    }
}

本文标签： 解决办法而不是超链接器中图片