---

itextpdf 加密解密

????????????????

???????????????????????

**************

相關類與接口

????????

PdfWriter

public class PdfWriter extends PdfOutputStream {private static final byte[] obj = ByteUtils.getIsoBytes(" obj\n");private static final byte[] endobj = ByteUtils.getIsoBytes("\nendobj\n");protected WriterProperties properties;PdfObjectStream objectStream;private Map<PdfIndirectReference, PdfIndirectReference> copiedObjects;private SmartModePdfObjectsSerializer smartModeSerializer;protected boolean isUserWarnedAboutAcroFormCopying;******** 構造方法public PdfWriter(File file) throws FileNotFoundException {public PdfWriter(OutputStream os) {public PdfWriter(OutputStream os, WriterProperties properties) {public PdfWriter(String filename) throws FileNotFoundException {public PdfWriter(String filename, WriterProperties properties) throws FileNotFoundException {******** 其他方法public PdfWriter setSmartMode(boolean smartMode) {public PdfWriter setCompressionLevel(int compressionLevel) {public boolean isFullCompression() {public int getCompressionLevel() {PdfObjectStream getObjectStream() {void flushCopiedObjects(long docId) {protected void initCryptoIfSpecified(PdfVersion version) {protected void flushObject(PdfObject pdfObject, boolean canBeInObjStm) {protected PdfObject copyObject(PdfObject obj, PdfDocument documentTo, boolean allowDuplicating) {protected void writeToBody(PdfObject pdfObj) {protected void writeHeader() {protected void flushWaitingObjects(Set<PdfIndirectReference> forbiddenToFlush) {protected void flushModifiedWaitingObjects(Set<PdfIndirectReference> forbiddenToFlush) {private void markArrayContentToFlush(PdfArray array) {private void markDictionaryContentToFlush(PdfDictionary dictionary) {private void markObjectToFlush(PdfObject pdfObject) {private static boolean checkTypeOfPdfDictionary(PdfObject dictionary, PdfName expectedType) {

??????????????

WriterProperties

public class WriterProperties {protected int compressionLevel = -1;protected Boolean isFullCompression = null;protected boolean smartMode = false;protected boolean addXmpMetadata;protected boolean addUAXmpMetadata = false;protected PdfVersion pdfVersion;protected EncryptionProperties encryptionProperties = new EncryptionProperties();protected PdfString initialDocumentId;protected PdfString modifiedDocumentId;******** 構造方法public WriterProperties() {}******** 其他方法public WriterProperties useSmartMode() {public WriterProperties addXmpMetadata() {public WriterProperties addUAXmpMetadata() {public WriterProperties setPdfVersion(PdfVersion version) {public WriterProperties setCompressionLevel(int compressionLevel) {public WriterProperties setInitialDocumentId(PdfString initialDocumentId) {public WriterProperties setModifiedDocumentId(PdfString modifiedDocumentId) {public WriterProperties setFullCompressionMode(boolean fullCompressionMode) {public WriterProperties setPublicKeyEncryption(Certificate[] certs, int[] permissions, int encryptionAlgorithm) {public WriterProperties setStandardEncryption(byte[] userPassword, byte[] ownerPassword, int permissions, int encryptionAlgorithm) {boolean isStandardEncryptionUsed() {boolean isPublicKeyEncryptionUsed() {

??????????????

EncryptionConstants

public final class EncryptionConstants {public static final int STANDARD_ENCRYPTION_40 = 0;public static final int STANDARD_ENCRYPTION_128 = 1;public static final int ENCRYPTION_AES_128 = 2;public static final int ENCRYPTION_AES_256 = 3;public static final int DO_NOT_ENCRYPT_METADATA = 8;public static final int EMBEDDED_FILES_ONLY = 24;public static final int ALLOW_PRINTING = 2052;public static final int ALLOW_MODIFY_CONTENTS = 8;public static final int ALLOW_COPY = 16;public static final int ALLOW_MODIFY_ANNOTATIONS = 32;public static final int ALLOW_FILL_IN = 256;public static final int ALLOW_SCREENREADERS = 512;public static final int ALLOW_ASSEMBLY = 1024;public static final int ALLOW_DEGRADED_PRINTING = 4;static final int ENCRYPTION_MASK = 7;private EncryptionConstants() {} }

??????????????????????

????????????????????????

PdfReader

public class PdfReader implements Closeable {public static final PdfReader.StrictnessLevel DEFAULT_STRICTNESS_LEVEL;private static final String endstream1 = "endstream";private static final String endstream2 = "\nendstream";private static final String endstream3 = "\r\nendstream";private static final String endstream4 = "\rendstream";private static final byte[] endstream;private static final byte[] endobj;protected static boolean correctStreamLength;private boolean unethicalReading;private boolean memorySavingMode;private PdfReader.StrictnessLevel strictnessLevel;private PdfIndirectReference currentIndirectReference;protected PdfTokenizer tokens;protected PdfEncryption decrypt;protected PdfVersion headerPdfVersion;protected long lastXref;protected long eofPos;protected PdfDictionary trailer;protected PdfDocument pdfDocument;protected PdfAConformanceLevel pdfAConformanceLevel;protected ReaderProperties properties;protected boolean encrypted;protected boolean rebuiltXref;protected boolean hybridXref;protected boolean fixedXref;protected boolean xrefStm;********* 構造方法public PdfReader(InputStream is) throws IOException {public PdfReader(InputStream is, ReaderProperties properties) throws IOException {public PdfReader(File file) throws FileNotFoundException, IOException {public PdfReader(String filename) throws IOException {public PdfReader(String filename, ReaderProperties properties) throws IOException {public PdfReader(IRandomAccessSource byteSource, ReaderProperties properties) throws IOException {PdfReader(IRandomAccessSource byteSource, ReaderProperties properties, boolean closeStream) throws IOException {********* 其他方法public byte[] computeUserPassword() { //計算用戶密碼public void close() throws IOException {public void setCloseStream(boolean closeStream) {public PdfReader.StrictnessLevel getStrictnessLevel() {public PdfReader setMemorySavingMode(boolean memorySavingMode) {public PdfReader setUnethicalReading(boolean unethicalReading) {public PdfReader setStrictnessLevel(PdfReader.StrictnessLevel strictnessLevel) {public long getLastXref() {public int getCryptoMode() {public long getFileLength() {public long getPermissions() {public byte[] getOriginalFileId() {public byte[] getModifiedFileId() {public RandomAccessFileOrArray getSafeFile() {public PdfAConformanceLevel getPdfAConformanceLevel() {public boolean hasXrefStm() {public boolean hasFixedXref() {public boolean hasHybridXref() {public boolean hasRebuiltXref() {public boolean isEncrypted() {public boolean isCloseStream() {public boolean isOpenedWithFullPermission() {public byte[] readStreamBytes(PdfStream stream, boolean decode) throws IOException {public byte[] readStreamBytesRaw(PdfStream stream) throws IOException {public InputStream readStream(PdfStream stream, boolean decode) throws IOException {public static byte[] decodeBytes(byte[] b, PdfDictionary streamDictionary) {public static byte[] decodeBytes(byte[] b, PdfDictionary streamDictionary, Map<PdfName, IFilterHandler> filterHandlers) {protected void readPdf() throws IOException {protected void readObjectStream(PdfStream objectStream) throws IOException {protected PdfObject readObject(PdfIndirectReference reference) {protected PdfObject readObject(boolean readAsDirect) throws IOException {protected PdfObject readReference(boolean readAsDirect) {protected PdfObject readObject(boolean readAsDirect, boolean objStm) throws IOException {protected PdfName readPdfName(boolean readAsDirect) {protected PdfDictionary readDictionary(boolean objStm) throws IOException {protected PdfArray readArray(boolean objStm) throws IOException {protected void readXref() throws IOException {protected PdfDictionary readXrefSection() throws IOException {protected boolean readXrefStream(long ptr) throws IOException {protected void fixXref() throws IOException {protected void rebuildXref() throws IOException {boolean isMemorySavingMode() {private void readDecryptObj() {private static PdfTokenizer getOffsetTokeniser(IRandomAccessSource byteSource, boolean closeStream) throws IOException {private PdfObject readObject(PdfIndirectReference reference, boolean fixXref) {private void checkPdfStreamLength(PdfStream pdfStream) throws IOException {private PdfObject createPdfNullInstance(boolean readAsDirect) {static {DEFAULT_STRICTNESS_LEVEL = PdfReader.StrictnessLevel.LENIENT;endstream = ByteUtils.getIsoBytes("endstream");endobj = ByteUtils.getIsoBytes("endobj");correctStreamLength = true;}********* 內部枚舉：StrictnessLevelpublic static enum StrictnessLevel {CONSERVATIVE(5000),LENIENT(3000);private final int levelValue;private StrictnessLevel(int levelValue) {public boolean isStricter(PdfReader.StrictnessLevel compareWith) {********* 靜態內部類：ReusableRandomAccessSourceprotected static class ReusableRandomAccessSource implements IRandomAccessSource {private ByteBuffer buffer;public ReusableRandomAccessSource(ByteBuffer buffer) {public int get(long offset) {public int get(long offset, byte[] bytes, int off, int len) {public long length() {public void close() {

??????????????????

ReaderProperties

public class ReaderProperties {protected byte[] password;protected Key certificateKey;protected Certificate certificate;protected String certificateKeyProvider;protected IExternalDecryptionProcess externalDecryptionProcess;protected MemoryLimitsAwareHandler memoryLimitsAwareHandler;public ReaderProperties() {}public ReaderProperties setPassword(byte[] password) {public ReaderProperties setPublicKeySecurityParams(Certificate certificate, Key certificateKey, String certificateKeyProvider, IExternalDecryptionProcess externalDecryptionProcess) {public ReaderProperties setPublicKeySecurityParams(Certificate certificate, IExternalDecryptionProcess externalDecryptionProcess) {public ReaderProperties setMemoryLimitsAwareHandler(MemoryLimitsAwareHandler memoryLimitsAwareHandler) {private void clearEncryptionParams() {

?????????????

???????????????????

**************

示例

????????

public class Test4 {private static final String source = "./source/1.pdf";private static final String dest = "./security/1.pdf";private static final String dest2 = "./security/2.pdf";private static final String dest3 = "./security/3.pdf";public static void fun() throws Exception{ //設置文件擁有者、用戶密碼，//讀取文件時需使用文件擁有者、或者用戶密碼PdfDocument pdfDocument = new PdfDocument(new PdfReader(source),new PdfWriter(dest, new WriterProperties().setStandardEncryption("123456".getBytes(StandardCharsets.UTF_8),"1qaz2w".getBytes(StandardCharsets.UTF_8),EncryptionConstants.ALLOW_PRINTING,EncryptionConstants.ENCRYPTION_AES_128)));pdfDocument.close();}public static void fun2() throws Exception{ //只設置文件擁有者密碼，不設置用戶密碼，//讀取文件時不需要使用密碼PdfDocument pdfDocument = new PdfDocument(new PdfReader(source),new PdfWriter(dest2, new WriterProperties().setStandardEncryption(null,"1qaz2w".getBytes(StandardCharsets.UTF_8),EncryptionConstants.ALLOW_PRINTING,EncryptionConstants.ENCRYPTION_AES_128)));pdfDocument.close();}public static void fun3() throws Exception{ //通過文件擁有密碼獲取用戶密碼PdfDocument pdfDocument = new PdfDocument(new PdfReader(dest,new ReaderProperties().setPassword("1qaz2w".getBytes(StandardCharsets.UTF_8))));byte[] passwordBytes = pdfDocument.getReader().computeUserPassword();System.out.println(passwordBytes!=null?new String(passwordBytes):"null");}public static void fun4() throws Exception{ //不設置用戶密碼，可直接讀取文件PdfDocument pdfDocument = new PdfDocument(new PdfReader(dest2).setUnethicalReading(true), new PdfWriter(dest3));pdfDocument.close();}public static void main(String[] args) throws Exception{fun();fun2();fun3();fun4();} }

?????????

fun：同時設置擁有者、用戶密碼，查看需輸入密碼（擁有者、用戶密碼均可）

? ? ? ? ? ? ? ? ?

? ? ? ? ? ? ? ? ??

? ? ? ? ? ? ? ? ? ?

fun2：只設置擁有者密碼、不設用戶密碼，可不輸入密碼直接查看文件

? ? ? ? ? ? ? ? ?

? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

? ? ? ? ? ? ? ? ? ? ? ? ? ??

總結

以上是生活随笔為你收集整理的itextpdf 加密解密的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。