#412 Get raw file name bytes via file and local file headers

src/main/java/net/lingala/zip4j/headers/FileHeaderFactory.java

@@ -16,6 +16,7 @@
 
 import java.nio.charset.Charset;
 
+import static net.lingala.zip4j.headers.HeaderUtil.getBytesFromString;
 import static net.lingala.zip4j.util.BitUtils.setBit;
 import static net.lingala.zip4j.util.BitUtils.unsetBit;
 import static net.lingala.zip4j.util.FileUtils.isZipEntryDirectory;
@@ -52,6 +53,7 @@ public FileHeader generateFileHeader(ZipParameters zipParameters, boolean isSpli
 
     String fileName = validateAndGetFileName(zipParameters.getFileNameInZip());
     fileHeader.setFileName(fileName);
+    fileHeader.setFileNameBytes(getBytesFromString(fileHeader.getFileName(), charset));
     fileHeader.setFileNameLength(determineFileNameLength(fileName, charset));
     fileHeader.setDiskNumberStart(isSplitZip ? currentDiskNumberStart : 0);
 
@@ -90,6 +92,7 @@ public LocalFileHeader generateLocalFileHeader(FileHeader fileHeader) {
     localFileHeader.setUncompressedSize(fileHeader.getUncompressedSize());
     localFileHeader.setFileNameLength(fileHeader.getFileNameLength());
     localFileHeader.setFileName(fileHeader.getFileName());
+    localFileHeader.setFileNameBytes(fileHeader.getFileNameBytes());
     localFileHeader.setEncrypted(fileHeader.isEncrypted());
     localFileHeader.setEncryptionMethod(fileHeader.getEncryptionMethod());
     localFileHeader.setAesExtraDataRecord(fileHeader.getAesExtraDataRecord());

src/main/java/net/lingala/zip4j/headers/HeaderReader.java

@@ -193,6 +193,7 @@ private CentralDirectory readCentralDirectory(RandomAccessFile zip4jRaf, RawIO r
         zip4jRaf.readFully(fileNameBuff);
         String fileName = decodeStringWithCharset(fileNameBuff, fileHeader.isFileNameUTF8Encoded(), charset);
         fileHeader.setFileName(fileName);
+        fileHeader.setFileNameBytes(fileNameBuff);
       } else {
         throw new ZipException("Invalid entry name in file header");
       }
@@ -558,6 +559,7 @@ public LocalFileHeader readLocalFileHeader(InputStream inputStream, Charset char
       String fileName = decodeStringWithCharset(fileNameBuf, localFileHeader.isFileNameUTF8Encoded(), charset);
       localFileHeader.setFileName(fileName);
       localFileHeader.setDirectory(fileName.endsWith("/") || fileName.endsWith("\\"));
+      localFileHeader.setFileNameBytes(fileNameBuf);
     } else {
       throw new ZipException("Invalid entry name in local file header");
     }

src/main/java/net/lingala/zip4j/headers/HeaderWriter.java

@@ -91,11 +91,7 @@ public void writeLocalFileHeader(ZipModel zipModel, LocalFileHeader localFileHea
         localFileHeader.setWriteCompressedSizeInZip64ExtraRecord(false);
       }
 
-      byte[] fileNameBytes = new byte[0];
-      if (isStringNotNullAndNotEmpty(localFileHeader.getFileName())) {
-        fileNameBytes = getBytesFromString(localFileHeader.getFileName(), charset);
-      }
-      rawIO.writeShortLittleEndian(byteArrayOutputStream, fileNameBytes.length);
+      rawIO.writeShortLittleEndian(byteArrayOutputStream, localFileHeader.getFileNameBytes().length);
 
       int extraFieldLength = 0;
       if (writeZip64Header) {
@@ -106,8 +102,8 @@ public void writeLocalFileHeader(ZipModel zipModel, LocalFileHeader localFileHea
       }
       rawIO.writeShortLittleEndian(byteArrayOutputStream, extraFieldLength);
 
-      if (fileNameBytes.length > 0) {
-        byteArrayOutputStream.write(fileNameBytes);
+      if (localFileHeader.getFileNameBytes().length > 0) {
+        byteArrayOutputStream.write(localFileHeader.getFileNameBytes());
       }
 
       //Zip64 should be the first extra data record that should be written
@@ -430,11 +426,7 @@ private void writeFileHeader(ZipModel zipModel, FileHeader fileHeader, ByteArray
         byteArrayOutputStream.write(longBuff, 0, 4);
       }
 
-      byte[] fileNameBytes = new byte[0];
-      if (isStringNotNullAndNotEmpty(fileHeader.getFileName())) {
-        fileNameBytes = getBytesFromString(fileHeader.getFileName(), charset);
-      }
-      rawIO.writeShortLittleEndian(byteArrayOutputStream, fileNameBytes.length);
+      rawIO.writeShortLittleEndian(byteArrayOutputStream, fileHeader.getFileNameBytes().length);
 
       //Compute offset bytes before extra field is written for Zip64 compatibility
       //NOTE: this data is not written now, but written at a later point
@@ -472,8 +464,8 @@ private void writeFileHeader(ZipModel zipModel, FileHeader fileHeader, ByteArray
       //offset local header - this data is computed above
       byteArrayOutputStream.write(offsetLocalHeaderBytes);
 
-      if (fileNameBytes.length > 0) {
-        byteArrayOutputStream.write(fileNameBytes);
+      if (fileHeader.getFileNameBytes().length > 0) {
+        byteArrayOutputStream.write(fileHeader.getFileNameBytes());
       }
 
       if (writeZip64ExtendedInfo) {

src/main/java/net/lingala/zip4j/model/AbstractFileHeader.java

@@ -18,6 +18,7 @@ public abstract class AbstractFileHeader extends ZipHeader {
   private int fileNameLength;
   private int extraFieldLength;
   private String fileName;
+  private byte[] fileNameBytes;
   private boolean isEncrypted;
   private EncryptionMethod encryptionMethod = EncryptionMethod.NONE;
   private boolean dataDescriptorExists;
@@ -111,6 +112,14 @@ public void setFileName(String fileName) {
     this.fileName = fileName;
   }
 
+  public byte[] getFileNameBytes() {
+    return fileNameBytes;
+  }
+
+  public void setFileNameBytes(byte[] fileNameBytes) {
+    this.fileNameBytes = fileNameBytes;
+  }
+
   public boolean isEncrypted() {
     return isEncrypted;
   }

src/test/java/net/lingala/zip4j/MiscZipFileIT.java

@@ -20,6 +20,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -632,6 +633,35 @@ public void testCloseZipFileMultipleTimesClosesAllStreams() throws IOException {
     assertInputStreamsAreClosed(Collections.singletonList(inputStream));
   }
 
+  @Test
+  public void testGetFileNameBytesReturnsValidBytes() throws IOException {
+    ZipFile zipFile = new ZipFile(generatedZipFile);
+    File firstFileToAdd = getTestFileFromResources("가나다.abc");
+    File secondFileToAdd = getTestFileFromResources("sample.pdf");
+    zipFile.addFile(firstFileToAdd);
+    zipFile.addFile(secondFileToAdd);
+
+    byte[] firstNameExpectedBytes = firstFileToAdd.getName().getBytes(StandardCharsets.UTF_8);
+    byte[] secondNameExpectedBytes = secondFileToAdd.getName().getBytes(StandardCharsets.UTF_8);
+
+    // Assert before and after creating a new instance of zipFile to make sure that the bytes are set
+    // even after adding entries to zip and not just when reading zip entries
+    assertFileNameBytesEqualsToFileName(zipFile, firstNameExpectedBytes, firstFileToAdd.getName());
+    assertFileNameBytesEqualsToFileName(zipFile, secondNameExpectedBytes, secondFileToAdd.getName());
+
+    zipFile = new ZipFile(generatedZipFile);
+
+    assertFileNameBytesEqualsToFileName(zipFile, firstNameExpectedBytes, firstFileToAdd.getName());
+    assertFileNameBytesEqualsToFileName(zipFile, secondNameExpectedBytes, secondFileToAdd.getName());
+  }
+
+  private void assertFileNameBytesEqualsToFileName(ZipFile zipFile, byte[] expectedFileNameBytes,
+                                                   String expectedFileName) throws ZipException {
+    FileHeader fileHeader = zipFile.getFileHeader(expectedFileName);
+    assertThat(fileHeader.getFileNameBytes()).isEqualTo(expectedFileNameBytes);
+    assertThat(new String(fileHeader.getFileNameBytes(), StandardCharsets.UTF_8)).isEqualTo(expectedFileName);
+  }
+
   private void assertInputStreamsAreClosed(List<InputStream> inputStreams) {
     for (InputStream inputStream : inputStreams) {
       try {