B4X

Unzip a Text File Entry into a StringBuilder Using ZipEntry.UnzipToSb

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This example demonstrates how to use the ZipEntry.UnzipToSb method to inflate a text file entry directly into a StringBuilder object.

The ZIP entry is uncompressed entirely in memory and appended to the StringBuilder without creating a temporary file on disk.

This is useful when:

• Processing text files directly in memory
• Avoiding temporary filesystem files
• Reading configuration files, JSON, XML, CSV, or source code from ZIP archives
• Automatically converting line endings while inflating the text

The srcCharset argument specifies how the uncompressed bytes should be interpreted, such as:

• utf-8
• utf-16
• windows-1252

The lineEndingBehavior argument controls line-ending conversion:

• 0 — Leave line endings unchanged
• 1 — Convert all line endings to bare LF
• 2 — Convert all line endings to CRLF

Suppose the ZIP archive contains:

config/settings.json

The example inflates the JSON file directly into a StringBuilder.

B4X

Dim success As Boolean = False

Dim zip As ChilkatZip
zip.Initialize("zip")

'  Open an existing ZIP archive.
success = zip.OpenZip("qa_data/zips/configFiles.zip")
If success = False Then
    Log(zip.LastErrorText)
    Return
End If


'  Locate the JSON file entry within the ZIP archive.
Dim entry As ChilkatZipEntry
entry.Initialize("entry")

success = zip.EntryOf("config/settings.json", entry)
If success = False Then
    Log("ZIP entry not found.")
    zip.CloseZip
    Return
End If


'  ------------------------------------------------------------
'  Inflate the ZIP entry directly into a StringBuilder.
'  
'  The uncompressed text is appended to the StringBuilder.
'  
Dim sb As ChilkatStringBuilder
sb.Initialize

'  Leave line endings unchanged.
Dim lineEndingBehavior As Int = 0

'  Interpret the uncompressed bytes as UTF-8 text.
Dim srcCharset As String = "utf-8"

success = entry.UnzipToSb(lineEndingBehavior, srcCharset, sb)
If success = False Then
    Log(entry.LastErrorText)
    Return
End If


Log("Uncompressed text:")
Log("")
Log(sb.GetAsString)

zip.CloseZip

Log("Done.")