Extract Data from AcroForm using Java

Extract form fields from a PDF document

Use com.aspose.pdf.facades.Form to read field names and values without working through the full document object model.

1. Open the source PDF form with the Form facade so AcroForm fields can be read without traversing the full document object model.
2. Call getFieldNames() to collect all field identifiers present in the form.
3. Iterate through those field names and call getField(fieldName) to read each field value.
4. Build the output string from the extracted key-value pairs and print the aggregated form data.
5. Close the Form facade in the finally block.

public static void extractFormFields(Path inputFile) {
    Form form = new Form(inputFile.toString());
    try {
        StringBuilder formValues = new StringBuilder("{");
        String[] fieldNames = form.getFieldNames();
        for (int i = 0; i < fieldNames.length; i++) {
            if (i > 0) {
                formValues.append(", ");
            }
            formValues.append(fieldNames[i]).append("=").append(form.getField(fieldNames[i]));
        }
        formValues.append("}");
        System.out.println(formValues);
    } finally {
        form.close();
    }
}

Retrieve form field value by Name

When you know the exact field name defined in the PDF form, you can retrieve its value directly with getField(fieldName) without iterating through the entire field collection.

1. Open the source PDF form with the Form facade.
2. Call getField(fieldName) with the requested field name to read its current value from the AcroForm data.
3. Print the extracted field value.
4. Close the Form facade in the finally block.

public static void extractFormFieldByTitle(Path inputFile, String fieldName) {
    Form form = new Form(inputFile.toString());
    try {
        String formValue = form.getField(fieldName);
        System.out.println(formValue);
    } finally {
        form.close();
    }
}

Extract form fields from PDF document to JSON

Form field values can also be extracted and stored as JSON. This is useful when PDF form data needs to be consumed by web applications, APIs, or other systems that work with JSON.

1. Open the source PDF form with the Form facade.
2. Call getFieldNames() to collect all available field identifiers from the AcroForm.
3. Iterate through those fields, escape the names and values, and build a JSON object string.
4. Write the JSON result to the output file.
5. Close the Form facade in the finally block.

public static void extractFormFieldsJson(Path inputFile, Path outputFile) throws Exception {
    Form form = new Form(inputFile.toString());
    try {
        StringBuilder json = new StringBuilder();
        json.append("{\n");
        String[] fieldNames = form.getFieldNames();
        for (int i = 0; i < fieldNames.length; i++) {
            String fieldName = fieldNames[i];
            json.append("    \"").append(escapeJson(fieldName)).append("\": \"")
                    .append(escapeJson(form.getField(fieldName))).append("\"");
            if (i < fieldNames.length - 1) {
                json.append(",");
            }
            json.append("\n");
        }
        json.append("}\n");
        Files.writeString(outputFile, json.toString());
    } finally {
        form.close();
    }
}

Export form data to XML from a PDF file

XML export is useful when PDF form data needs to be consumed by systems that work with structured XML data.

1. Create the Form facade without binding a document yet.
2. Open an output stream for the XML file and bind the source PDF to the facade with bindPdf(...).
3. Call exportXml(stream) so the current form field data is serialized as XML.
4. Close the Form facade after the export completes.

public static void extractDataToXml(Path inputFile, Path outputFile) throws Exception {
    Form form = new Form();
    try (OutputStream stream = Files.newOutputStream(outputFile)) {
        form.bindPdf(inputFile.toString());
        form.exportXml(stream);
    } finally {
        form.close();
    }
}

Export Data to FDF from a PDF File

FDF (Forms Data Format) is commonly used to exchange AcroForm field data independently of the PDF document.

1. Create the Form facade without binding a document yet.
2. Open an output stream for the FDF file and bind the source PDF to the facade with bindPdf(...).
3. Call exportFdf(stream) so the form field data is serialized in FDF format.
4. Close the Form facade after the export completes.

public static void extractDataToFdf(Path inputFile, Path outputFile) throws Exception {
    Form form = new Form();
    try (OutputStream stream = Files.newOutputStream(outputFile)) {
        form.bindPdf(inputFile.toString());
        form.exportFdf(stream);
    } finally {
        form.close();
    }
}

Export Data to XFDF from a PDF File

XFDF is the XML-based representation of Forms Data Format and is convenient for exchanging form data with systems that work with XML.

1. Create the Form facade without binding a document yet.
2. Open an output stream for the XFDF file and bind the source PDF to the facade with bindPdf(...).
3. Call exportXfdf(stream) so the form field data is serialized in XFDF format.
4. Close the Form facade after the export completes.

public static void extractDataToXfdf(Path inputFile, Path outputFile) throws Exception {
    Form form = new Form();
    try (OutputStream stream = Files.newOutputStream(outputFile)) {
        form.bindPdf(inputFile.toString());
        form.exportXfdf(stream);
    } finally {
        form.close();
    }
}