用於加密/解密pdf文件的Java API

Question

我需要加密和解密pdf文件。有沒有免費或低成本的Java API呢？基本上我需要隱藏來自普通用戶的文件。任何其他建議，以編程方式實現？

感謝， 深

Answer 1

使用iText：

// Assuming you provide the following yourself: 
    File inputFile; 
    File outputFile; 
    String userPassword; 
    String ownerPassword; 
    // A bit-field containing file permissions. 
    int permissions = PDFWriter.ALLOW_PRINTING | PDFWriter.ALLOW_COPY; 

    PdfReader reader = new PdfReader(inputFile); 
    PdfEncryptor.encrypt(reader, new FileOutputStream(outputFile), 
     ENCRYPTION_AES128, userPassword, ownerPassword, 
     permissions); 

下面是PDFEncryptor和PDFWriter（用於權限）的API。

Answer 2

iText支持加密。

Answer 3

使用PDFBox（基於Decrypt.java代碼）：

PDDocument document = null; 

try 
{ 
    document = PDDocument.load(infile); 

    if(document.isEncrypted()) 
    { 
     DecryptionMaterial decryptionMaterial = null; 
     decryptionMaterial = new StandardDecryptionMaterial(password); 
     document.openProtection(decryptionMaterial); 
     AccessPermission ap = document.getCurrentAccessPermission(); 
     if(ap.isOwnerPermission()) 
     { 
      document.setAllSecurityToBeRemoved(true); 
      document.save(outfile); 
     } 
     else 
     { 
      throw new IOException(
      "Error: You are only allowed to decrypt a document with the owner password."); 
     } 
    } 
    else 
    { 
     System.err.println("Error: Document is not encrypted."); 
    } 
} 
finally 
{ 
    if(document != null) 
    { 
     document.close(); 
    } 
}