...

Right click on WebContent and Select New->jsp.
Name the jsp as index.jsp and Select Next.
Select Finish. This will create a template for index.jsp.

Add the following code to index.jsp.

Code Block

title	index.jsp
borderStyle	solid

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Image Upload</title>
</head>
<body>
<h2>Select a Image and Upload it</h2>
<form action="/WebJDBC/ImageUpload">
<table>
<tr>
<td>
Location of the Image(full path)
</td>
<td>
<Input type="text" name="ImageLoc">
</td>
</tr>
<tr>
<td>
Name of the Image(Unique Name)
</td>
<td>
<Input type="text" name="ImageName">
</td>
</tr>
<tr>
<td>
<Input type="submit" value="submit">
</td>
<tr>
</table>
</form>
</body>
</html>

The <form action="/WebJDBC/ImageUpload"> suggests that once the form is submitted the request will be passed to ImageUpload. Next step is to add the servlet ImageUpload to process the request sent by the JSP client.

Right click on Java Resources and Select New->other.
Select Web->Servlet. Select Next.
Name the java package as jdbc and class as ImageUpload. Select Next->Next.
Select Finish.

Add the following code to ImageUpload.java.

Code Block

title	ImageUpload.java
borderStyle	solid

package jdbc;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

public class ImageUpload extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
	@Resource(name="jdbc/userds")
	 private DataSource ds;
   static final long serialVersionUID = 1L;
   
 	public ImageUpload() {
		super();
	}   	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doProcess(request, response);
	}  	
	
	protected void doProcess(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		Connection dbconnect = null;
		PreparedStatement stmnt = null;
		String pic=request.getParameter("ImageLoc");
		String name=request.getParameter("ImageName");
		try{
			File f= new File(pic);
			FileInputStream fis=new FileInputStream(f);
			dbconnect= ds.getConnection();
			stmnt = dbconnect.prepareStatement("INSERT INTO PICTURES (" + "NAME," + "PIC )" + " VALUES(?,?)");
			stmnt.setString(1, name);
			stmnt.setBinaryStream(2, fis, (int)f.length());
			stmnt.execute();
			PrintWriter out= response.getWriter();
			out.println("Congratulations your image has been successfully uploaded");			
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		finally
		{
		try{
    		dbconnect.close();
    		stmnt.close();
    	}catch(SQLException e){
    		e.printStackTrace();
    	}    
		}
	}
		
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doProcess(request, response);
	}   	  	    
}

This completes the code for Image Upload.

Code to retrieve the image from derby database

...

Code Block

title	ImageDownload.jsp
borderStyle	solid


<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Download Image</title>
</head>
<body>
<h2>Name a Image to download</h2>
<form action="/WebJDBC/ImageDownload">
<table>
<tr>
<td>
Name of the Image
</td>
<td>
<Input type="text" name="ImageName">
</td>
</tr>
<tr>
<td>
<Input type="submit" value="submit">
</td>
<tr>
</table>
</form>
</body>
</html>

...

title	ImageDownload.java
borderStyle	solid

...

Once a request is submitted from index.jsp for a image upload with the name and exact location of image. The request is send to ImageUpload servlet.

String pic=request.getParameter("ImageLoc");- Retrieves the location of the image
String name=request.getParameter("ImageName");- Retrieves the name of the image

Once we have the image available a new File object is created out of the image. Thereafter the image file is read as a binary stream. PreparedStatement is used to insert the image onto database.

This completes the code for Image Upload.

Code to retrieve the image from derby database

Create a jsp page with the name ImageDownload.jsp.

Append the jsp with the following code

Code Block

title	ImageDownload.jsp
borderStyle	solid


<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Download Image</title>
</head>
<body>
<h2>Name a Image to download</h2>
<form action="/WebJDBC/ImageDownload">
<table>
<tr>
<td>
Name of the Image
</td>
<td>
<Input type="text" name="ImageName">
</td>
</tr>
<tr>
<td>
<Input type="submit" value="submit">
</td>
<tr>
</table>
</form>
</body>
</html>

As can be seen from <form action="/WebJDBC/ImageDownload"> this jsp requests ImageDownload servlet when the form is submitted.

Create a new servlet ImageDownload.java and add the following code

Code Block

title	ImageDownload.java
borderStyle	solid


package jdbc;

import java.io.IOException;
import java.io.OutputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

 public class ImageDownload extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
	 @Resource(name = "jdbc/userds")
		private DataSource ds;
   static final long serialVersionUID = 1L;
   
	public ImageDownload() {
		super();
	}   	
	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doProcess(request, response);	
	}  	
	protected void doProcess(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		Connection dbconnect = null;
		ResultSet rs = null;
		PreparedStatement stmnt = null;
		try {
			dbconnect = ds.getConnection();
			String s=request.getParameter("ImageName");
			stmnt = dbconnect.prepareStatement("SELECT PIC FROM PICTURES WHERE NAME=?");
			stmnt.setString(1, s);
			rs = stmnt.executeQuery();
			if (rs.next()) {
				// Get as a BLOB
				Blob aBlob = rs.getBlob(1);
				byte[] b = new byte[4096];
				java.io.InputStream ip = aBlob.getBinaryStream();
				OutputStream out = null;
				int c = 0;
				out = response.getOutputStream();
				response.setContentType("image/jpeg");
				while (c != -1) {
					c = ip.read(b);
					out.write(b);
					out.flush();
				}
				ip.close();
				
			}

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
        	try{
        		dbconnect.close();
        		stmnt.close();
        	    rs.close();
        	}catch(SQLException e){
        		e.printStackTrace();
        	}        	        	
        }

	} 
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doProcess(request, response);
	}   	  	    
}

ImageDownload servlet works in a similar way and once the request is sent from ImageDownload.jsp to ImageDownload servlet. The servlet uses

String s=request.getParameter("ImageName");- To retrieve the name of the image to be downloaded
rs = stmnt.executeQuery();- To execute the PreparedStatement
Blob aBlob = rs.getBlob(1);- Data is stored as a Blob datatype
java.io.InputStream ip = aBlob.getBinaryStream();- Blob data is retrieved as a binary stream
response.setContentType("image/jpeg");- sets the output content type as a Image datatype
c = ip.read(b);, out.write(b);, out.flush();- Data is read as a byte buffer and written on the web page. After each write the buffet is flushed.

This completes the code for Image download.

Modifying deployment plan

...

Child pages

Versions Compared

Old Version 19

New Version 20

Key

Code to retrieve the image from derby database

Code to retrieve the image from derby database

Modifying deployment plan

Child pages

Page History

Versions Compared

Old Version 19

New Version 20

Key

Code to retrieve the image from derby database

Code to retrieve the image from derby database

Modifying deployment plan