向已签名的Excel文件添加数字签名
可能的使用场景
Aspose.Cells提供 Workbook.addDigitalSignature(DigitalSignatureCollection digitalSignatureCollection) 方法,您可以利用它向已经签名的Excel文件添加数字签名。
对已签名的 Excel 文件添加数字签名
以下示例代码解释了如何使用 Workbook.addDigitalSignature(DigitalSignatureCollection digitalSignatureCollection) 方法向已经签名的Excel文件添加数字签名。请检查本代码中使用的 示例Excel文件。此文件已经进行了数字签名。请检查代码生成的 输出Excel文件。我们在此代码中使用了名为 AsposeTest.pfx 的演示证书,密码为 aspose。屏幕截图显示了执行后代码对示例Excel文件的影响。
示例代码
// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-Java | |
// Certificate file and its password | |
String certFileName = "AsposeTest.pfx"; | |
String password = "aspose"; | |
// Load the workbook which is already digitally signed to add new digital signature | |
Workbook workbook = new Workbook(srcDir + "sampleDigitallySignedByCells.xlsx"); | |
// Create the digital signature collection | |
DigitalSignatureCollection dsCollection = new DigitalSignatureCollection(); | |
// Create new digital signature and add it in digital signature collection | |
// ------------------------------------------------------------ | |
// --------------Begin::creating signature--------------------- | |
// Load the certificate into an instance of InputStream | |
InputStream inStream = new FileInputStream(srcDir + certFileName); | |
// Create an instance of KeyStore with PKCS12 cryptography | |
java.security.KeyStore inputKeyStore = java.security.KeyStore.getInstance("PKCS12"); | |
// Use the KeyStore.load method to load the certificate stream and its password | |
inputKeyStore.load(inStream, password.toCharArray()); | |
// Create an instance of DigitalSignature and pass the instance of KeyStore, password, comments and time | |
DigitalSignature signature = new DigitalSignature(inputKeyStore, password, | |
"Aspose.Cells added new digital signature in existing digitally signed workbook.", | |
com.aspose.cells.DateTime.getNow()); | |
dsCollection.add(signature); | |
// ------------------------------------------------------------ | |
// --------------End::creating signature----------------------- | |
// Add digital signature collection inside the workbook | |
workbook.addDigitalSignature(dsCollection); | |
// Save the workbook and dispose it. | |
workbook.save(outDir + "outputDigitallySignedByCells.xlsx"); | |
workbook.dispose(); |