hwplib

The library supports a wide range of HWP document manipulations, including:

• Document Structure: Adding paragraphs from other files (Adding_Paragraph_Between_HWPFile), changing paper size (Changing_PaperSize).
• Tables: Inserting tables (Inserting_Table), merging cells (Merging_Cell), and removing rows (Removing_Table_Row).
• Content: Inserting images (Inserting_Image), inserting hyperlinks (Inserting_HyperLink), and setting character shapes like font size or underlines (Inserting_CharShape).
• Fields: Finding and setting field text and finding all fields.

The following features are not currently supported by hwplib:

• Reading or writing encrypted HWP files.
• Converting HWP files to Image, PDF, or HTML formats.
• Retrieving specific page content or calculating the total number of pages.

Add the following dependency to your Maven pom.xml to use the hwplib library for handling HWP (Hangul Word Processor) files.

<dependency>
    <groupId>kr.dogfoot</groupId>
    <artifactId>hwplib</artifactId>
</dependency>

Use the HWPReader class to load HWP files into memory as HWPFile objects. You can read from a local file path or a remote URL.

// Reading from a local file
String filename = "sample.hwp"; 
HWPFile hwpFile = HWPReader.fromFile(filename); 

// Reading from a URL
String url = "http://example.com/sample.hwp";
HWPFile hwpFile = HWPReader.fromURL(url); 

The TextExtractor class allows you to extract text from an HWPFile using different strategies defined by TextExtractMethod:

• OnlyMainParagraph: Extracts text only from the main paragraphs.
• InsertControlTextBetweenParagraphText: Inserts the text of controls (like images or tables) between paragraph texts during extraction.
• AppendControlTextAfterParagraphText: Appends the text of controls after the paragraph text.

For very large files, use the specialized extraction methods designed to prevent memory issues.

HWPFile hwpFile = HWPReader.fromFile(filename); 
// Extract text with control text inserted between paragraphs
String hwpText = TextExtractor.extract(hwpFile, TextExtractMethod.InsertControlTextBetweenParagraphText);

You can find and manage field text (often used for forms/templates) using the FieldFinder class.

• FieldFinder.getClickHereText(hwpFile, "fieldName"): Retrieves the text associated with a specific field name.
• FieldFinder.getClickHereText(hwpFile, "fieldName", TextExtractMethod.OnlyMainParagraph): Retrieves field text with specific extraction constraints.
• FieldFinder.findAll(hwpFile): Finds all fields in the document.
• Setting_FieldText: Methods are available to set text for specific fields.

// Get text from a specific field
String text1 = FieldFinder.getClickHereText(hwpFile, "필드이름");

// Get text with specific extraction method
String text2 = FieldFinder.getClickHereText(hwpFile, "필드1", TextExtractMethod.OnlyMainParagraph);

Use ControlFinder.find() to search for specific controls within an HWPFile by implementing the ControlFilter interface.

public static class MyControlFilter implements ControlFilter {
    @Override
    public boolean isMatched(Control control, Paragraph paragraph, Section section) {
        // Define your filtering logic here
        return true; 
    }
}

// Usage
ArrayList<Control> result = ControlFinder.find(hwpFile, new MyControlFilter());

After modifying a HWPFile object, you can save it back to a file using HWPWriter.toFile() or output it to a stream using HWPWriter.toStream().

// Open a file
String filename = "test.hwp"; 
HWPFile hwpFile = HWPReader.fromFile(filename); 

if (hwpFile != null) {
    // ... perform modifications ...

    // Save to a new file
    String writePath = "test-edited.hwp";
    HWPWriter.toFile(hwpFile, writePath);
}