com.aspose.words

Example:

String textDoc = "      Line 1 \n" +
        "    Line 2   \n" +
        " Line 3       ";

// Create a "TxtLoadOptions" object, which we can pass to a document's constructor
// to modify how we load a plaintext document.
TxtLoadOptions loadOptions = new TxtLoadOptions();

// Set the "LeadingSpacesOptions" property to "TxtLeadingSpacesOptions.Preserve"
// to preserve all whitespace characters at the start of every line.
// Set the "LeadingSpacesOptions" property to "TxtLeadingSpacesOptions.ConvertToIndent"
// to remove all whitespace characters from the start of every line,
// and then apply a left first line indent to the paragraph to simulate the effect of the whitespaces.
// Set the "LeadingSpacesOptions" property to "TxtLeadingSpacesOptions.Trim"
// to remove all whitespace characters from every line's start.
loadOptions.setLeadingSpacesOptions(txtLeadingSpacesOptions);

// Set the "TrailingSpacesOptions" property to "TxtTrailingSpacesOptions.Preserve"
// to preserve all whitespace characters at the end of every line. 
// Set the "TrailingSpacesOptions" property to "TxtTrailingSpacesOptions.Trim" to 
// remove all whitespace characters from the end of every line.
loadOptions.setTrailingSpacesOptions(txtTrailingSpacesOptions);

Document doc = new Document(new ByteArrayInputStream(textDoc.getBytes()), loadOptions);
ParagraphCollection paragraphs = doc.getFirstSection().getBody().getParagraphs();

switch (txtLeadingSpacesOptions) {
    case TxtLeadingSpacesOptions.CONVERT_TO_INDENT:
        Assert.assertEquals(37.8d, paragraphs.get(0).getParagraphFormat().getFirstLineIndent());
        Assert.assertEquals(25.2d, paragraphs.get(1).getParagraphFormat().getFirstLineIndent());
        Assert.assertEquals(6.3d, paragraphs.get(2).getParagraphFormat().getFirstLineIndent());

        Assert.assertTrue(paragraphs.get(0).getText().startsWith("Line 1"));
        Assert.assertTrue(paragraphs.get(1).getText().startsWith("Line 2"));
        Assert.assertTrue(paragraphs.get(2).getText().startsWith("Line 3"));
        break;
    case TxtLeadingSpacesOptions.PRESERVE:
        Assert.assertTrue(IterableUtils.matchesAll(paragraphs, s -> s.getParagraphFormat().getFirstLineIndent() == 0.0d));

        Assert.assertTrue(paragraphs.get(0).getText().startsWith("      Line 1"));
        Assert.assertTrue(paragraphs.get(1).getText().startsWith("    Line 2"));
        Assert.assertTrue(paragraphs.get(2).getText().startsWith(" Line 3"));
        break;
    case TxtLeadingSpacesOptions.TRIM:
        Assert.assertTrue(IterableUtils.matchesAll(paragraphs, s -> s.getParagraphFormat().getFirstLineIndent() == 0.0d));

        Assert.assertTrue(paragraphs.get(0).getText().startsWith("Line 1"));
        Assert.assertTrue(paragraphs.get(1).getText().startsWith("Line 2"));
        Assert.assertTrue(paragraphs.get(2).getText().startsWith("Line 3"));
        break;
}

switch (txtTrailingSpacesOptions) {
    case TxtTrailingSpacesOptions.PRESERVE:
        Assert.assertTrue(paragraphs.get(0).getText().endsWith("Line 1 \r"));
        Assert.assertTrue(paragraphs.get(1).getText().endsWith("Line 2   \r"));
        Assert.assertTrue(paragraphs.get(2).getText().endsWith("Line 3       \f"));
        break;
    case TxtTrailingSpacesOptions.TRIM:
        Assert.assertTrue(paragraphs.get(0).getText().endsWith("Line 1\r"));
        Assert.assertTrue(paragraphs.get(1).getText().endsWith("Line 2\r"));
        Assert.assertTrue(paragraphs.get(2).getText().endsWith("Line 3\f"));
        break;
}