web下载七牛云上面的图片资源

本文将怎么通过浏览器打包下载七牛云服务器上面的图片资源;

**如果不用压缩打包处理,可以直接获取流后用对应的out输出就行,不做具体解析;**

1 先讲怎么打包下载吧.ZipOutputStream我用的是这个工具类

创建: ZipOutputStream out = new ZipOutputStream(new FileOutputStream(strZipName));

通过在for里面,对out.putNextEntry(new ZipEntry(“名字” + i+”.png”));

注意,要对资源流进行关闭处理

String[] fileUrl 是对应在七牛云上面的资源,可以直接在浏览器上面直接访问到的资源.

@Test
public void downloadFile() throws Exception {
byte[] buffer = new byte[1024];
// 生成的ZIP文件名为Demo.zip
String strZipName = "Demo.zip";
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(strZipName));
String[] fileUrl = {
"http://lddn.com/1=4411b99f-e6f3-4d95-9c75-50ef1100f2d9_2016-07-08%2019-31-27%E5%B1%8F%E5%B9%95%E6%88%AA%E5%9B%BE.png",
"http://dn.com/3=855eb361-0068-4d20-88d8-ae5e440fddcf_2016-10-10%2010-22-20%E5%B1%8F%E5%B9%95%E6%88%AA%E5%9B%BE.png" };

for (int i = 0; i < fileUrl.length; i++) {
InputStream inStream = getInputStream(fileUrl[i]);
// FileInputStream fis = new FileInputStream(file1[i]);
out.putNextEntry(new ZipEntry("名字" + i+".png"));
int len;
// 读入需要下载的文件的内容，打包到zip文件
while ((len = inStream.read(buffer)) > 0) {
out.write(buffer, 0, len);
}
out.closeEntry();
inStream.close();
}
out.flush();
out.close();
System.out.println("生成Demo.zip成功");

}

上面是普通java文件下载文件到本地的方法;
下面将一下web下载

2 web下在对应文件,先创建jsp(不做介绍).

3 对应的控制器

@ResponseBody
@RequestMapping("download")
public BaseVO downloadImage(HttpServletResponse response, AdMaterialParam param) {
//要添加HttpServletResponse方法,因为浏览器下载要对对应的头数据进行设置;
}

response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(file, "UTF-8"));

adMaterialService.**download**(url);为下载图片返回流数据

try {
response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(file, "UTF-8"));
// ZipOutputStream out = new ZipOutputStream(new FileOutputStream(file));
ZipOutputStream out = new ZipOutputStream(response.getOutputStream());
byte[] buffer = new byte[1024];
for (AdImagePath adImagePath : adImagePaths) {
String url = qiniuYunUtils.getUrl() + adImagePath.getImageUrl();
InputStream inputStream = adMaterialService.download(url);

String imageName = adMaterialService.getImageOriginalFileName(adImagePath.getImageUrl());
out.putNextEntry(new ZipEntry(imageName));
int length;
while ((length = inputStream.read(buffer)) > 0) {
out.write(buffer, 0, length);
}
if (out != null) {
out.closeEntry();
}
if (inputStream != null) {
inputStream.close();
}
}
if (out != null) {
out.flush();
out.close();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

**对网络资源的下载;**

@Override
public InputStream download(String url) {
try {
URL imageUrl = new URL(url);
HttpURLConnection httpURLConnection = (HttpURLConnection) imageUrl.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setConnectTimeout(5 * 1000);
return httpURLConnection.getInputStream();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

public String getImageOriginalFileName(String url) {
int indexFirst = url.indexOf("_") + 1;
if (indexFirst > 0) {
return url.substring(indexFirst);
}
return "";
}