I wrote a small piece of code to do some pdf encryption with openpdf, and intellij`s sonarlint was complaining about “Resources should be closed” more details here
non compliant public class PasswordProtectedPDF { private static final Logger logger = Logger.getLogger(PasswordProtectedPDF.class.getName()); static final String USER_PASSWORD = "111"; static final String OWNER_PASSWORD = "111"; public static void main(String[] args) { try { File f = new File("1_protected.pdf"); FileOutputStream out = new FileOutputStream(f); File pdfFile = new File("1.pdf"); PdfReader reader = new PdfReader(pdfFile.getPath()); PdfStamper stamper = new PdfStamper(reader, out); HashMap<String, String> info = new HashMap<>(); info.put("Producer", ""); reader.getInfo().forEach((key, value) -> { logger.info("Key: " + key + ", Value: " + value); }); stamper.setInfoDictionary(info); stamper.setEncryption(USER_PASSWORD.getBytes(), OWNER_PASSWORD.getBytes(), PdfWriter.ALLOW_PRINTING, PdfWriter.ENCRYPTION_AES_128); stamper.close(); logger.info("Password protected PDF created successfully."); } catch (IOException e) { logger.severe("Error creating password protected PDF: " + e.getMessage()); } } } Compliant public class PasswordProtectedPDF { private static final Logger logger = Logger.getLogger(PasswordProtectedPDF.class.getName()); static final String USER_PASSWORD = "111"; static final String OWNER_PASSWORD = "111"; public static void main(String[] args) { try ( FileOutputStream out = new FileOutputStream(new File("1_protected.pdf")); PdfReader reader = new PdfReader(new File("1.pdf").getPath()) ) { PdfStamper stamper = new PdfStamper(reader, out); HashMap<String, String> info = new HashMap<>(); info.put("Producer", ""); reader.getInfo().forEach((key, value) -> { logger.info("Key: " + key + ", Value: " + value); }); stamper.setInfoDictionary(info); stamper.setEncryption(USER_PASSWORD.getBytes(), OWNER_PASSWORD.getBytes(), PdfWriter.ALLOW_PRINTING, PdfWriter.ENCRYPTION_AES_128); stamper.close(); logger.info("Password protected PDF created successfully."); } catch (IOException e) { logger.severe("Error creating password protected PDF: " + e.getMessage()); } } } just a reminder we can define multiple resources in try block
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