使用PdfiumAndroid这里提到的PdfiumAndroid ……

用于生成pdf thumb的示例代码

//PdfiumAndroid (https://github.com/barteksc/PdfiumAndroid)

//https://github.com/barteksc/AndroidPdfViewer/issues/49

void generateImageFromPdf(Uri pdfUri) {

int pageNumber = 0;

PdfiumCore pdfiumCore = new PdfiumCore(this);

try {

//http://www.programcreek.com/java-api-examples/index.php?api=android.os.ParcelFileDescriptor

ParcelFileDescriptor fd = getContentResolver().openFileDescriptor(pdfUri, "r");

PdfDocument pdfDocument = pdfiumCore.newDocument(fd);

pdfiumCore.openPage(pdfDocument, pageNumber);

int width = pdfiumCore.getPageWidthPoint(pdfDocument, pageNumber);

int height = pdfiumCore.getPageHeightPoint(pdfDocument, pageNumber);

Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);

pdfiumCore.renderPageBitmap(pdfDocument, bmp, pageNumber, 0, 0, width, height);

saveImage(bmp);

pdfiumCore.closeDocument(pdfDocument); // important!

} catch(Exception e) {

//todo with exception

}

}

public final static String FOLDER = Environment.getExternalStorageDirectory() + "/PDF";

private void saveImage(Bitmap bmp) {

FileOutputStream out = null;

try {

File folder = new File(FOLDER);

if(!folder.exists())

folder.mkdirs();

File file = new File(folder, "PDF.png");

out = new FileOutputStream(file);

bmp.compress(Bitmap.CompressFormat.PNG, 100, out); // bmp is your Bitmap instance

} catch (Exception e) {

//todo with exception

} finally {

try {

if (out != null)

out.close();

} catch (Exception e) {

//todo with exception

}

}

}

更新：

在build.gradle中包含库

compile 'com.github.barteksc:pdfium-android:1.4.0'

用于生成任何PDF页面的图像：

通过传递存储在存储中的任何PDF uri来调用方法generateImageFromPdf(uri).

该方法将在您的存储的PDF文件夹中生成PDF.png.