How to write a servlet that rotates images?

Question

Hi, I just wanted to share this servlet, it takes 2 arguments (img-> image name, rot → image rotation) loads the image from the image directory, rotates it and outputs it to the servlet stream

you can find it in the answer below

Answer 1

 package at.buchinger.mapdisplay;

 import java.awt.geom.AffineTransform;
 import java.awt.image.AffineTransformOp;
 import java.awt.image.BufferedImage;
 import java.io.File;
 import java.io.IOException;
 import java.util.Iterator;

 import javax.imageio.ImageIO;
 import javax.imageio.ImageWriter;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.ServletOutputStream;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 / **
  * Servlet implementation class RotatedImage
  * /
 public class RotatedImage extends HttpServlet {
     private static final long serialVersionUID = 1L;

     / **
      * @see HttpServlet # HttpServlet ()
      * /
     public RotatedImage () {
         super ();
         // TODO Auto-generated constructor stub
     }

     / **
      * @see HttpServlet # doGet (HttpServletRequest request, HttpServletResponse response)
      * /
     protected void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

         String img = (String) request.getParameter ("img");
         String path = getServletContext (). GetRealPath ("image /" + img);


         String r;
         r = request.getParameter ("rot");
         if (r == null) {
             r = "0";
         }
         double rot = Double.parseDouble (r);

         BufferedImage image = ImageIO.read (new File (path));
         AffineTransform tx = new AffineTransform ();

         tx.rotate (Math.toRadians (rot), image.getWidth () / 2, image.getHeight () / 2);

         AffineTransformOp op = new AffineTransformOp (tx, AffineTransformOp.TYPE_BILINEAR);
         image = op.filter (image, null);



            ServletContext sc = getServletContext ();
             String filename = getServletContext (). GetRealPath (path);

             // Get the MIME type of the image
             String mimeType = sc.getMimeType (filename);
             if (mimeType == null) {
                 sc.log ("Could not get MIME type of" + filename);
                 response.setStatus (HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
                 return
             }


             // Set content type
             response.setContentType (mimeType);
             ServletOutputStream out = response.getOutputStream ();
             Iterator iter = ImageIO.getImageWritersByMIMEType (mimeType);

             ImageIO.write (image, "png", out);

     }

     / **
      * @see HttpServlet # doPost (HttpServletRequest request, HttpServletResponse response)
      * /
     protected void doPost (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         doGet (request, response);
     }

 }