Java (480)
Spire.PDF for Java supports deleting a specific child bookmark, a parent bookmark along with its child bookmark(s) or delete all the bookmarks from a PDF file. In this article, you will learn how to delete PDF bookmarks using Spire.PDF for Java.
The input PDF file:

import com.spire.pdf.PdfDocument;
public class DeleteBookmarks {
public static void main(String[] args) {
//Create a PdfDocument instance
PdfDocument pdf = new PdfDocument();
//Load the PDF file
pdf.loadFromFile("AddBookmarks.pdf");
//Delete the first child bookmark
pdf.getBookmarks().get(0).removeAt(0);
//Delete the first bookmark along with its child bookmark
//pdf.getBookmarks().removeAt(0);
//Delete all the bookmarks
//pdf.getBookmarks().clear();
//Save the result file
pdf.saveToFile("DeleteBookmarks.pdf");
}
}
The output PDF file after deleting the first child bookmark:

This article demonstrates how to auto fit a Word table to content or to window, as well as how to fix the cloumn widths, by using Spire.Doc for Java.
Autofit to content
import com.spire.doc.*;
public class AutofitToContent {
public static void main(String[] args) {
//Create a Document object
Document document = new Document();
//Add a section
Section section = document.addSection();
//Add a table
Table table = section.addTable();
table.resetCells(3, 2);
//Add content to the cells
table.get(0,0).addParagraph().appendText("Product Code");
table.get(0,1).addParagraph().appendText("Description");
table.get(1,0).addParagraph().appendText("T1052");
table.get(1,1).addParagraph().appendText("AdvoCareSlim Tropical Swirl");
table.get(2,0).addParagraph().appendText("T1062");
table.get(2,1).addParagraph().appendText("AdvoCareSlim Caffeine Free Strawberry Kiwi");
//Autofit column widths to contents
table.autoFit(AutoFitBehaviorType.Auto_Fit_To_Contents);
//Save the document
document.saveToFile("AutofitToContent.docx", FileFormat.Docx);
}
}

Autofit to window
import com.spire.doc.*;
public class AutofitToWindow {
public static void main(String[] args) {
//Create a Document object
Document document = new Document();
//Add a section
Section section = document.addSection();
//Add a table
Table table = section.addTable();
table.resetCells(3, 2);
//Add content to the cells
table.get(0,0).addParagraph().appendText("Product Code");
table.get(0,1).addParagraph().appendText("Description");
table.get(1,0).addParagraph().appendText("T1052");
table.get(1,1).addParagraph().appendText("AdvoCareSlim Tropical Swirl");
table.get(2,0).addParagraph().appendText("T1062");
table.get(2,1).addParagraph().appendText("AdvoCareSlim Caffeine Free Strawberry Kiwi");
//Autofit column widths to window
table.autoFit(AutoFitBehaviorType.Auto_Fit_To_Window);
//Save the document
document.saveToFile("AutofitToWindow.docx", FileFormat.Docx);
}
}

Fix column width
import com.spire.doc.*;
public class FixColumnWidths {
public static void main(String[] args) {
//Create a Document object
Document document = new Document();
//Add a section
Section section = document.addSection();
//Add a table
Table table = section.addTable();
table.resetCells(3, 2);
//Add content to the cells
table.get(0, 0).addParagraph().appendText("Product Code");
table.get(0, 1).addParagraph().appendText("Description");
table.get(1, 0).addParagraph().appendText("T1052");
table.get(1, 1).addParagraph().appendText("AdvoCareSlim Tropical Swirl");
table.get(2, 0).addParagraph().appendText("T1062");
table.get(2, 1).addParagraph().appendText("AdvoCareSlim Caffeine Free Strawberry Kiwi");
//Set the column widths
for (int i = 0; i < table.getRows().getCount(); i++) {
table.get(i,0).setCellWidth(80f,CellWidthType.Point);
table.get(i,1).setCellWidth(160f,CellWidthType.Point);
}
//Fix the column widths so that the column width does not increases when the content exceeds the width
table.autoFit(AutoFitBehaviorType.Fixed_Column_Widths);
//Save the document
document.saveToFile("FixColumnWidths.docx", FileFormat.Docx);
}
}

This article demonstrates how to set the transparency of image on a PDF file using Spire.PDF for Java.
import com.spire.pdf.*;
import com.spire.pdf.graphics.*;
import java.awt.geom.*;
import java.awt.*;
public class ImageTransparency {
public static void main(String[] args) {
//Create a PDFDocument
PdfDocument doc = new PdfDocument();
//Add a section
PdfSection section = doc.getSections().add();
// Load image and set its width and height
PdfImage image = PdfImage.fromFile("logo.png");
double imageWidth = image.getPhysicalDimension().getWidth() / 3;
double imageHeight = image.getPhysicalDimension().getHeight() / 3;
//Add a page
PdfPageBase page = section.getPages().add();
float pageWidth = (float) page.getCanvas().getClientSize().getWidth();
float y = 10;
//Draw Title and set the font and format
y = y + 5;
PdfBrush brush = new PdfSolidBrush(new PdfRGBColor(new Color(255,69,0)));
PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", Font.BOLD,12));
PdfStringFormat format = new PdfStringFormat(PdfTextAlignment.Center);
String text = String.format(" Set image Transparency ");
page.getCanvas().drawString(text, font, brush, pageWidth / 2, y, format);
Dimension2D size = font.measureString(text, format);
y = y + (float) size.getHeight() + 6;
//Set image transparency
page.getCanvas().setTransparency(0.2f, 0.2f, PdfBlendMode.Normal);
//Add image to the page
page.getCanvas().drawImage(image, 0, y, imageWidth, imageHeight);
page.getCanvas().save();
// Save pdf file.
doc.saveToFile("output/Transparency.pdf");
// Close pdf file
doc.close();
}
}
Effective screenshot after adding the image to PDF and set the image transparency:
