如何从Zip文件读取评论？

Question

如何使用Java在Zip文件中读写评论？

我可以这样写评论：

FileOutputStream fos = new FileOutputStream(output); 
ZipOutputStream zos = new ZipOutputStream(fos); 
zos.setComment("BMC Comment"); 

Answer 1

检查这个帖子：

• http://www.flattermann.net/2009/01/read-a-zip-file-comment-with-java/

编辑：不幸的是，原来的链接现已无法使用，这里有一个网页档案连结：

http://web.archive.org/web/20100117212418/http://www.flattermann.net:80/2009/01/read-a-zip-file-comment-with-java/

对于后人，这里的要点（略格式）：

private static String getZipCommentFromBuffer (byte[] buffer, int len) { 
    byte[] magicDirEnd = {0x50, 0x4b, 0x05, 0x06}; 
    int buffLen = Math.min(buffer.length, len); 

    // Check the buffer from the end 
    for (int i = buffLen - magicDirEnd.length - 22; i >= 0; i--) { 
    boolean isMagicStart = true; 

    for (int k = 0; k < magicDirEnd.length; k++) { 
     if (buffer[i + k] != magicDirEnd[k]) { 
     isMagicStart = false; 
     break; 
     } 
    } 

    if (isMagicStart) { 
     // Magic Start found! 
     int commentLen = buffer[i + 20] + buffer[i + 21] * 256; 
     int realLen = buffLen - i - 22; 
     System.out.println ("ZIP comment found at buffer position " 
     + (i + 22) + " with len = " + commentLen + ", good!"); 

     if (commentLen != realLen) { 
     System.out.println ("WARNING! ZIP comment size mismatch: " 
      + "directory says len is " + commentLen 
      + ", but file ends after " + realLen + " bytes!"); 
     } 

     String comment = new String (buffer, i + 22, Math.min(commentLen, realLen)); 
     return comment; 
    } 
    } 

    System.out.println ("ERROR! ZIP comment NOT found!"); 
    return null; 
} 

Answer 2

尝试：

java.util.zip.ZipFile.getComment()