Android下载PDF文件

男娘i 2022-02-25 11:42 479阅读 0赞

## 1.下载PDF文件到本地 ##

private void downFile(String urlString){
            try {
                URL url = new URL(urlString);
                HttpURLConnection connection = (HttpURLConnection)
                        url.openConnection();
                connection.setRequestMethod("GET");
                connection.setDoInput(true);
                connection.setDoOutput(true);
                connection.setUseCaches(false);
                connection.setConnectTimeout(5000);
                connection.setReadTimeout(5000);
                //实现连接
                connection.connect();
     
                if (connection.getResponseCode() == 200) {
                    InputStream is = connection.getInputStream();
                    //以下为下载操作
                    byte[] arr = new byte[1];
                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    BufferedOutputStream bos = new BufferedOutputStream(baos);
                    int n = is.read(arr);
                    while (n > 0) {
                        bos.write(arr);
                        n = is.read(arr);
                    }
                    bos.close();
                    String path = Environment.getExternalStorageDirectory()
                            + "/download/";
                    String[] name = urlString.split("/");
                    path = path + name[name.length - 1];
                    File file = new File(path);
                    FileOutputStream fos = new FileOutputStream(file);
                    fos.write(baos.toByteArray());
                    fos.close();
                    //关闭网络连接
                    connection.disconnect();
                   Log.d("下载完成","下载完成");
                    openPDF(file);//打开PDF文件
                }
            } catch (Exception e) {
                // TODO: handle exception
                System.out.println(e.getMessage());
            }
        }

## 2.打开PDF文件 ##

private void openPDF(File file) {
            if (file.exists()) {
                Log.d("打开","打开");
                Uri path1 = Uri.fromFile(file);
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setDataAndType(path1, "application/pdf");
                intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
     
                try {
                    startActivity(intent);
                }
                catch (Exception e) {
                    Log.d("打开失败","打开失败");
                }
            }
        }

## 3.新建一个线程调用下载方法 ##

private class MyAsyncTask extends AsyncTask<String, Void, File> {
    
            @Override
            protected File doInBackground(String... str) {
                return downFile(str[0]);//开始下载
            }
    
            @Override
            protected void onPostExecute(final File file) {
                //下载完成，修改UI
            }
        }

## 4.调用 ##

String url = "https://staticzcjb.weibangong.com/pdf/business_license.pdf";
    new MyAsyncTask().execute(url, null, null);