下载一个PDF文件并将其保存到SD卡,然后从那里读 [英] Download a pdf file and save it to sdcard and then read it from there
问题描述
可能重复:
从URL 下载PDF阅读它
Possible Duplicate:
Download PDF from url and read it
我必须从网址下载一个PDF文件并将其保存到SD卡上,然后去读它。 我经历了很多codeS了,我发现这个
I have to download a pdf file from an url and save it to the sd card and then to read it. I got through many codes and i found this
Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("*url for your pdf*"));
startActivity(browserIntent);
但如何将它保存在SD卡在我所希望的路径,然后从那里阅读。
but how to save it in sd-card in my desired path and then read it from there.
推荐答案
请看一看这个的链接。
它包含了你的需求的例子。下面还有在链接的信息的摘要。
It Contains an example of your requirement. Below there is a summary of the information in the link.
第一步在AndroidManifest.xml中声明persmissions
First step declaring persmissions in AndroidManifest.xml
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
创建一个下载器类
Create a downloader class
public class Downloader {
public static void DownloadFile(String fileURL, File directory) {
try {
FileOutputStream f = new FileOutputStream(directory);
URL u = new URL(fileURL);
HttpURLConnection c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.connect();
InputStream in = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = in.read(buffer)) > 0) {
f.write(buffer, 0, len1);
}
f.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
最后,创建从互联网上下载的PDF文件中的一个活动,
Finally creating an activity which downloads the PDF file from internet,
public class PDFFromServerActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
String extStorageDirectory = Environment.getExternalStorageDirectory()
.toString();
File folder = new File(extStorageDirectory, "pdf");
folder.mkdir();
File file = new File(folder, "Read.pdf");
try {
file.createNewFile();
} catch (IOException e1) {
e1.printStackTrace();
}
Downloader.DownloadFile("http://www.nmu.ac.in/ejournals/aspx/courselist.pdf", file);
showPdf();
}
public void showPdf()
{
File file = new File(Environment.getExternalStorageDirectory()+"/pdf/Read.pdf");
PackageManager packageManager = getPackageManager();
Intent testIntent = new Intent(Intent.ACTION_VIEW);
testIntent.setType("application/pdf");
List list = packageManager.queryIntentActivities(testIntent, PackageManager.MATCH_DEFAULT_ONLY);
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
Uri uri = Uri.fromFile(file);
intent.setDataAndType(uri, "application/pdf");
startActivity(intent);
}
}
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