android对PDF文件的操作（上传、预览、下载和转存相册）

2023-08-27 08:36| 来源: 网络整理| 查看: 265

一、上传PDF文件到服务器

前段时间有一个老项目需要添加对PDF的上传、下载和预览等操作，我这边完成之后整理发一下博客，因为项目较老，框架技术也不是先进技术。

上传文件主要使用了OkGo网络请求框架，如果是使用OKhttp的将网络请求代码和回调方法改成相应的即可，因为上传文件需要用到网络请求权限和文件读写权限，记得需要在AndroidManifest.xml中配置:

上传文件代码：

（1）点击按钮调用打开手机的文件选择器：

// 打开系统的文件选择器 public void pickFile(View view) { int permission = ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE);//缺少什么权限就写什么权限 if (permission != PackageManager.PERMISSION_GRANTED) { // We don't have permission so prompt the user ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE,}, 0); } int permission2 = ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);//缺少什么权限就写什么权限 if (permission2 != PackageManager.PERMISSION_GRANTED) { // We don't have permission so prompt the user ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,}, 0); } else{ Intent intent = new Intent(Intent.ACTION_GET_CONTENT); //intent.setType("image/*");//选择图片 //intent.setType("audio/*"); //选择音频 //intent.setType("video/*"); //选择视频（mp4 3gp 是android支持的视频格式） //intent.setType("video/*;image/*");//同时选择视频和图片 intent.setType("*/*");//无类型限制 intent.addCategory(Intent.CATEGORY_OPENABLE); startActivityForResult(intent, 1); } }

（2）回调方法获取文件的真实路径，根据android的版本不同，采用不同的方法

// 获取文件的真实路径 String path; @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode == Activity.RESULT_OK) { Uri uri = data.getData(); if ("file".equalsIgnoreCase(uri.getScheme())) {//使用第三方应用打开 path = uri.getPath(); ShowDiglog(path); System.out.println("获得地址1"+path); return; } if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT) {//4.4以后 path = getPath(this, uri); System.out.println("获得地址2"+path); ShowDiglog(path); } else {//4.4以下下系统调用方法 path = getRealPathFromURI(uri); System.out.println("获得地址3"+path); ShowDiglog(path); } } } public String getRealPathFromURI(Uri contentUri) { String res = null; String[] proj = {MediaStore.Images.Media.DATA}; Cursor cursor = getContentResolver().query(contentUri, proj, null, null, null); if (null != cursor && cursor.moveToFirst()) { ; int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA); res = cursor.getString(column_index); cursor.close(); } return res; } /** * 专为Android4.4设计的从Uri获取文件绝对路径，以前的方法已不好使 */ @SuppressLint("NewApi") public String getPath(final Context context, final Uri uri) { final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT; // DocumentProvider if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) { // ExternalStorageProvider if (isExternalStorageDocument(uri)) { final String docId = DocumentsContract.getDocumentId(uri); final String[] split = docId.split(":"); final String type = split[0]; if ("primary".equalsIgnoreCase(type)) { return Environment.getExternalStorageDirectory() + "/" + split[1]; } } // DownloadsProvider else if (isDownloadsDocument(uri)) { final String id = DocumentsContract.getDocumentId(uri); final Uri contentUri = ContentUris.withAppendedId( Uri.parse("content://downloads/public_downloads"), Long.valueOf(id)); return getDataColumn(context, contentUri, null, null); } // MediaProvider else if (isMediaDocument(uri)) { final String docId = DocumentsContract.getDocumentId(uri); final String[] split = docId.split(":"); final String type = split[0]; Uri contentUri = null; if ("image".equals(type)) { contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI; } else if ("video".equals(type)) { contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI; } else if ("audio".equals(type)) { contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; } final String selection = "_id=?"; final String[] selectionArgs = new String[]{split[1]}; return getDataColumn(context, contentUri, selection, selectionArgs); } } // MediaStore (and general) else if ("content".equalsIgnoreCase(uri.getScheme())) { return getDataColumn(context, uri, null, null); } // File else if ("file".equalsIgnoreCase(uri.getScheme())) { return uri.getPath(); } return null; } /** * Get the value of the data column for this Uri. This is useful for * MediaStore Uris, and other file-based ContentProviders. * * @param context The context. * @param uri The Uri to query. * @param selection (Optional) Filter used in the query. * @param selectionArgs (Optional) Selection arguments used in the query. * @return The value of the _data column, which is typically a file path. */ public String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) { Cursor cursor = null; final String column = "_data"; final String[] projection = {column}; try { cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null); if (cursor != null && cursor.moveToFirst()) { final int column_index = cursor.getColumnIndexOrThrow(column); return cursor.getString(column_index); } } finally { if (cursor != null) cursor.close(); } return null; } /** * @param uri The Uri to check. * @return Whether the Uri authority is ExternalStorageProvider. */ public boolean isExternalStorageDocument(Uri uri) { return "com.android.externalstorage.documents".equals(uri.getAuthority()); } /** * @param uri The Uri to check. * @return Whether the Uri authority is DownloadsProvider. */ public boolean isDownloadsDocument(Uri uri) { return "com.android.providers.downloads.documents".equals(uri.getAuthority()); } /** * @param uri The Uri to check. * @return Whether the Uri authority is MediaProvider. */ public boolean isMediaDocument(Uri uri) { return "com.android.providers.media.documents".equals(uri.getAuthority()); }

（3）点击弹窗的上传按钮，调用网络接口，实现文件上传

public void ShowDiglog(final String path){ MyAlertDialog myAlertDialog = new MyAlertDialog(this).builder() .setTitle("上传简历？") .setMsg(path) .setPositiveButton("上传", new View.OnClickListener() { @Override public void onClick(View v) { uploadFile(path); System.out.println("上传"); } }).setNegativeButton("取消", new View.OnClickListener() { @Override public void onClick(View v) { System.out.println("取消"); } }); myAlertDialog.show(); } public void uploadFile(String path){ File file = new File(path); OkGo.post(NetUrl.DNS + NetUrl.UploadCv) .tag(this) .params("file", file) .execute(new StringCallback() { @Override public void onSuccess(Response response) { try { JSONObject jsonObject = new JSONObject(response.body()); System.out.println("输出结果"+jsonObject); int infoCode = jsonObject.getInt("status"); if (infoCode == 0) { Tools.toast(IntroFileActivity.this, "简历上传成功!"); introAdapter.clear(); pageNumber = 1; initData(pageNumber); } } catch (JSONException e) { e.printStackTrace(); } } }); }

二、预览网络上的PDF文件

因为android原生无法直接预览PDF文件，所有简单的就是将PDF文件下载下来转成图片进行预览，但是这样子下载到用户的手机中对用户不友好。在考虑之后，决定抵赖第三方的依赖来实现，需要引入pdfviewpager组件，在gradle组件中添加以下代码：

（1）添加依赖：

//预览pdf文件 compile('es.voghdev.pdfviewpager:library:1.0.3') { exclude module: 'support-v4' exclude group: 'com.android.support' }

（2）界面设计（引入依赖的界面组件）：

显示效果如图，实际手机中不会有PDF图标：

在这里插入图片描述

（3）Activity代码：

三、PDF文件的下载和转存相册

其实下载文件倒是简单，就是简单的文件下载方式，这里附上一个文件下载工具类，对异常处理和回调进行封装。

（1）文件下载工具类：

/** * 文件下载工具类（单例模式） */ public class DownloadUtil { private static DownloadUtil downloadUtil; private final OkHttpClient okHttpClient; public static DownloadUtil get() { if (downloadUtil == null) { downloadUtil = new DownloadUtil(); } return downloadUtil; } private DownloadUtil() { okHttpClient = new OkHttpClient(); } /** * @param url 下载连接 * @param destFileDir 下载的文件储存目录 * @param destFileName 下载文件名称 * @param listener 下载监听 */ public void download(final String url, final String destFileDir, final String destFileName, final OnDownloadListener listener) { Request request = new Request.Builder().url(url).build(); okHttpClient.newCall(request).enqueue(new Callback() { @Override public void onFailure(Call call, IOException e) { // 下载失败监听回调 listener.onDownloadFailed(e); } @Override public void onResponse(Call call, Response response) throws IOException { InputStream is = null; byte[] buf = new byte[2048]; int len = 0; FileOutputStream fos = null; // 储存下载文件的目录 File dir = new File(destFileDir); if (!dir.exists()) { dir.mkdirs(); } File file = new File(dir, destFileName); try { is = response.body().byteStream(); long total = response.body().contentLength(); fos = new FileOutputStream(file); long sum = 0; while ((len = is.read(buf)) != -1) { fos.write(buf, 0, len); sum += len; int progress = (int) (sum * 1.0f / total * 100); // 下载中更新进度条 listener.onDownloading(progress); } fos.flush(); // 下载完成 listener.onDownloadSuccess(file); } catch (Exception e) { listener.onDownloadFailed(e); } finally { try { if (is != null) is.close(); } catch (IOException e) { } try { if (fos != null) fos.close(); } catch (IOException e) { } } } }); } public interface OnDownloadListener { /** * @param file 下载成功后的文件 */ void onDownloadSuccess(File file); /** * @param progress 下载进度 */ void onDownloading(int progress); /** * @param e 下载异常信息 */ void onDownloadFailed(Exception e); } }

（2）文件下载和转存相册

在文件下载之后，回调方法返回其真实路径，通过真实路径获取到PDF文件，并将其转成Bitmap，在进一步保存图片到手机中，最后将图片文件插入到系统图库，实现了转存相册功能。Activity完整代码如下：

public class ActivityInvoiceFile extends AppCompatActivity implements DownloadFile.Listener,OnClickListener { private RelativeLayout pdf_root; private ProgressBar pb_bar; private TextView TextViewDownload; private RemotePDFViewPager remotePDFViewPager; private String pdfUrl = ""; private String invoiceNo = ""; private PDFPagerAdapter adapter; private Context mContext; private String destFileDir; private String destFileName; protected RequestCall mRequest; private ProgressDialog progressDialog; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_invoice_file); mContext = ActivityInvoiceFile.this; setupView(); setupData(); setDownloadListener(); } private void setupView() { findViewById(R.id.toolbar_back).setOnClickListener(this); pdf_root = (RelativeLayout) findViewById(R.id.remote_pdf_root); pb_bar = (ProgressBar) findViewById(R.id.pb_bar); TextViewDownload = (TextView)findViewById(R.id.textView_download); TextViewDownload.setOnClickListener(this); } protected void setupData() { Intent intent = getIntent(); pdfUrl = intent.getStringExtra("pdfUrl"); invoiceNo = intent.getStringExtra("invoiceNo"); } /*设置监听*/ protected void setDownloadListener() { final DownloadFile.Listener listener = this; remotePDFViewPager = new RemotePDFViewPager(this, pdfUrl, listener); remotePDFViewPager.setId(R.id.pdfViewPager); } /*加载成功调用*/ @Override public void onSuccess(String url, String destinationPath) { pb_bar.setVisibility(View.GONE); adapter = new PDFPagerAdapter(this, FileUtil.extractFileNameFromURL(url)); remotePDFViewPager.setAdapter(adapter); updateLayout(); } /*更新视图*/ private void updateLayout() { pdf_root.removeAllViewsInLayout(); pdf_root.addView(remotePDFViewPager, LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT); } /*加载失败调用*/ @Override public void onFailure(Exception e) { pb_bar.setVisibility(View.GONE); Toast.makeText(mContext, "文件加载失败", Toast.LENGTH_SHORT).show(); } @Override public void onProgressUpdate(int progress, int total) { } @Override public void onClick(View v) { // TODO Auto-generated method stub switch (v.getId()) { case R.id.toolbar_back: finish(); break; case R.id.textView_download: downFile(pdfUrl); break; default: break; } } /** * 文件下载 * * @param url */ public void downFile(String url) { progressDialog = new ProgressDialog(ActivityInvoiceFile.this); progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); progressDialog.setProgress(0); progressDialog.setMax(100); progressDialog.show(); progressDialog.setCancelable(true); DownloadUtil.get().download(url, Environment.getExternalStorageDirectory().getAbsolutePath()+File.separator+"Invoices", "Invoice"+invoiceNo+".pdf", new DownloadUtil.OnDownloadListener() { @Override public void onDownloadSuccess(File file) { if (progressDialog != null && progressDialog.isShowing()) { progressDialog.dismiss(); } Looper.prepare();//增加部分 AlertsavePhoto("已下载至手机内部存储设备根目录下Invoices文件夹中","是否转存图片至相册？",file); Looper.loop();//增加部分 } @Override public void onDownloading(int progress) { progressDialog.setProgress(progress); } @Override public void onDownloadFailed(Exception e) { if (progressDialog != null && progressDialog.isShowing()) { progressDialog.dismiss(); } Looper.prepare();//增加部分 Toast.makeText(mContext, "文件下载失败", Toast.LENGTH_SHORT).show(); Looper.loop();//增加部分 } }); } //转存图片对话框 private void AlertsavePhoto(String title, String msg, final File file) { new Builder(mContext) .setTitle(title) .setMessage(msg) .setNegativeButton(android.R.string.cancel, null) .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); ArrayList bitmap = pdfToBitmap(file); saveImageToGallery(mContext,bitmap); } }) .create() .show(); } //PDF转成Bitmap private ArrayList pdfToBitmap(File pdfFile) { ArrayList bitmaps = new ArrayList(); try { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { PdfRenderer renderer = new PdfRenderer(ParcelFileDescriptor.open(pdfFile, ParcelFileDescriptor.MODE_READ_ONLY)); Bitmap bitmap; final int pageCount = renderer.getPageCount(); Log.e("test_sign", "图片de 张数： " +pageCount); for (int i = 0; i ex.printStackTrace(); } return bitmaps; } private void saveImageToGallery(Context context, ArrayList bitmaps) { // 首先保存图片 File appDir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "InvoicePhoto"); for (int i = 0; i appDir.mkdir(); } String fileName = System.currentTimeMillis() + ".jpg"; File file = new File(appDir, fileName); Log.e("test_sign", "图片全路径localFile = " + appDir.getAbsolutePath() + fileName); FileOutputStream fos = null; try { fos = new FileOutputStream(file); bitmaps.get(i).compress(Bitmap.CompressFormat.JPEG, 100, fos); fos.flush(); fos.close(); } catch (FileNotFoundException e) { Toast.makeText(mContext, "保存到相册失败!", Toast.LENGTH_LONG).show(); e.printStackTrace(); } catch (IOException e) { Toast.makeText(mContext, "保存到相册失败!", Toast.LENGTH_LONG).show(); e.printStackTrace(); } finally { if (fos != null) { try { fos.close(); //回收 bitmaps.get(i).recycle(); } catch (IOException e) { e.printStackTrace(); } } } // 其次把文件插入到系统图库 try { MediaStore.Images.Media.insertImage(context.getContentResolver(), file.getAbsolutePath(), fileName, null); } catch (FileNotFoundException e) { Toast.makeText(mContext, "保存到相册失败!", Toast.LENGTH_LONG).show(); e.printStackTrace(); } } Toast.makeText(mContext, "已保存到手机相册!", Toast.LENGTH_LONG).show(); // 最后通知图库更新 sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(new File(appDir.getPath())))); } }

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