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Password Protection

This chapter introduces how to read and write password-protected Excel files.

Overview​

Fesod supports Excel's built-in password protection for both reading and writing. Use .password("xxx") on the builder to encrypt/decrypt files. For .xlsx output, Fesod uses Apache POI's encryption (AES-based) which can be memory-intensive for large workbooks. For legacy .xls files, password protection behaves as write-protection rather than full content encryption, so behavior and security guarantees differ from .xlsx.

Writing with Password​

Code Example​

@Test
public void passwordWrite() {
    String fileName = "passwordWrite" + System.currentTimeMillis() + ".xlsx";

    FesodSheet.write(fileName)
        .password("your_password")
        .head(DemoData.class)
        .sheet("PasswordSheet")
        .doWrite(data());
}

Reading with Password​

Code Example​

@Test
public void passwordRead() {
    String fileName = "path/to/encrypted.xlsx";

    FesodSheet.read(fileName, DemoData.class, new DemoDataListener())
        .password("your_password")
        .sheet()
        .doRead();
}

Security Notes​

  • Excel password protection encrypts the file content, making it unreadable without the password.
  • Without the correct password, reading will throw an EncryptedDocumentException.
  • In production, avoid hardcoding passwords — use configuration files or secrets management.