problem in fetch the images from database.

[sarojni agrwal]

package com.lp;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class rt1
 */
@WebServlet("/rt1")
public class rt1 extends HttpServlet {
	private static final long serialVersionUID = 1L;

	private static final int BUFFER_SIZE = 4096;
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String url = "jdbc:mysql://localhost:3306/appdb";
		String user = "root";
		String password = "yellow1";

		//String filePath = "D:/photos/images.jpg";

		try {
			
			Class.forName("com.mysql.jdbc.Driver");
			Connection conn = DriverManager.getConnection(url, user, password);

			String sql = "SELECT photo FROM contacts";
			PreparedStatement statement = conn.prepareStatement(sql);
			

			ResultSet result = statement.executeQuery();
			
			int i = 0;
			while (result.next()) {
				Blob blob = result.getBlob("photo");
				InputStream inputStream = blob.getBinaryStream();
				OutputStream outputStream = new FileOutputStream(new File("D:/test" + i + ".jpg"));
				
				i++;
				
				int bytesRead = (int)blob.length();
				byte[] buffer = new byte[BUFFER_SIZE];
				while((bytesRead = inputStream.read(buffer)) != -1)
				{
					outputStream.write(buffer , 0,bytesRead);
				}

				
				
	
				
				
			response.getOutputStream();
				
				if (buffer != null && buffer.length > 0) {
					 response.setContentType("image/jpg");
					 response.getOutputStream().write(buffer);
					 response.getOutputStream().flush();
					 response.getOutputStream().close();
					} 

				inputStream.close();
				outputStream.close();
				
				System.out.println("File saved");
			}
			conn.close();
		} catch (SQLException ex) {
			ex.printStackTrace();
		} catch (IOException ex) {
			ex.printStackTrace();
		}catch (ClassNotFoundException ex) {
		ex.printStackTrace();
	}

}
}
	

I created this servlet and try to find out the images in local disk d's test folder from database, but images did not fetch in folder why?

[Bear Bibeault]

You'll need to give us more information that that. Have you used logging or other techniques to debug where the method is going awry?

And rt1 is not an appropriate class name.

[sarojni agrwal]

this is servlet where I have inserted images in database........

package com.lp;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;

import com.mysql.jdbc.PreparedStatement;



/**
 * Servlet implementation class uploadServlet
 */
@WebServlet("/uploadServlet")
@MultipartConfig(maxFileSize = 16177215)	// upload file's size up to 16MB

public class uploadServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	
	// database connection settings
			private String dbURL = "jdbc:mysql://localhost:3306/appdb";
			private String dbUser = "root";
			private String dbPass = "yellow1";
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		

		
		// gets values of text fields
				String firstName = request.getParameter("firstName");
				String lastName = request.getParameter("lastName");
				
				InputStream inputStream = null;	// input stream of the upload file
				
				// obtains the upload file part in this multipart request
				Part filePart = request.getPart("photo");
				if (filePart != null) {
					// prints out some information for debugging
					System.out.println(filePart.getName());
					System.out.println(filePart.getSize());
					System.out.println(filePart.getContentType());
					
					// obtains input stream of the upload file
					inputStream = filePart.getInputStream();
				}
				
				Connection conn = null;	// connection to the database
				String message = null;	// message will be sent back to client
				
				try {
					// connects to the database
					DriverManager.registerDriver(new com.mysql.jdbc.Driver());
					conn = DriverManager.getConnection(dbURL, dbUser, dbPass);

					// constructs SQL statement
					String sql = "INSERT INTO contacts (firstname, lastname, photo) values (?, ?, ?)";
					PreparedStatement statement = (PreparedStatement) conn.prepareStatement(sql);
					statement.setString(1, firstName);
					statement.setString(2, lastName);
					
					if (inputStream != null) {
						// fetches input stream of the upload file for the blob column
						statement.setBlob(3, inputStream);
					}

					// sends the statement to the database server
					int row = statement.executeUpdate();
					if (row > 0) {
						message = "File uploaded and saved into database";
					}
				} catch (SQLException ex) {
					message = "ERROR: " + ex.getMessage();
					ex.printStackTrace();
				} finally {
					if (conn != null) {
						// closes the database connection
						try {
							conn.close();
						} catch (SQLException ex) {
							ex.printStackTrace();
						}
					}
					// sets the message in request scope
					request.setAttribute("Message", message);
					
					// forwards to the message page
					getServletContext().getRequestDispatcher("/Message.jsp").forward(request, response);

	}

}
}

and when I try to fetch only one image then no problem it fetched like this.

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.mysql.jdbc.Blob;

/**
 * Servlet implementation class tf
 */
@WebServlet("/tf")
public class tf extends HttpServlet {
	private static final long serialVersionUID = 1L;
	
	private static final int BUFFER_SIZE = 4096;

	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		String url = "jdbc:mysql://localhost:3306/appdb";
		String user = "root";
		String password = "yellow1";
		try
		{
			
			Class.forName("com.mysql.jdbc.Driver");
		Connection conn = DriverManager.getConnection(url, user, password);

		String sql = "SELECT  *FROM contacts";
		PreparedStatement statement = conn.prepareStatement(sql);
		
		ResultSet result = statement.executeQuery();
		
		if(result.next()){//now on 1st row  
			              
		Blob b=(Blob) result.getBlob(3);//2 means 2nd column data  
		byte barr[]=b.getBytes(1,(int)b.length());//1 means first image  
			             
			FileOutputStream fout=new FileOutputStream("D:/photos/sonoo1.jpg");  
			fout.write(barr);  
			              
			fout.close();  
			}//end of if  
			System.out.println("ok");  
			              
			conn.close();


System.out.println("File saved");
		
		


	}catch (SQLException ex) {
		ex.printStackTrace();
	} catch (IOException ex) {
		ex.printStackTrace();
	}catch (ClassNotFoundException ex) {
			ex.printStackTrace();
	}
	}
}
 



		

[Bear Bibeault]

Bear Bibeault wrote:You'll need to give us more information that that. Have you used logging or other techniques to debug where the method is going awry?

You have not put forward any new information on the nature of the problem. Are you getting a connection? Are you getting anything back from the database? What debugging have you done?

And rt1 is not an appropriate class name.

Please use appropriate naming conventions. Code that does not follow the naming conventions is surpassingly hard to read. Class names should be complete words and start with an uppercase letter.

[sarojni agrwal]

I got nothing from database, see in image and also my local disk d's folder is empty.

[Bear Bibeault]

Well, of course you're not going to see anything in the browser -- you are writing to a file.

Are you looking for the file in the right place?

And you still haven't answered by questions? Connection? Resultset length? Any exceptions being thrown?

Add logging to your servlet if you are not set up to step though a debugger.

[sarojni agrwal]

The code, I posted in which the line (OutputStream outputStream = new FileOutputStream(new File("D:/test1" + i + ".jpg"));) is retrieve images from database and store in local disk D, yes I got images in local disk D, but from there , I can not fetch and display images in jsp, so now I want these images in my java project's web container, (and ofcourse, I can not copy and paste, because I insert and store images dynamically at user request), so in that case I changed my path like (OutputStream outputStream = new FileOutputStream(new File("/jewellery/WebContent:/test1" + i + ".jpg"));), but I could not find any image in WebContent folder, it shows me error filenot found, how will this possible???

[Bear Bibeault]

Why are you even writing a file to the disk? If your aim is to display it in a JSP page, the image should be written as the response to a servlet, not written to a file. The image tag in the JSP would reference the servlet.

Perhaps looking through the ServletsFaq at this article https://coderanch.com/t/660125/Wiki/Image-Servlet would be helpful.

[sarojni agrwal]

I can not figure out, means, instead of this line (OutputStream outputStream = new FileOutputStream(new File("D:/test1" + i + ".jpg"));), which line should I write? because, I need to store images somewhere right? and I know to display only one image in jsp by img tag, but how I display multiple images in jsp by img tag?

[Bear Bibeault]

sarojni agrwal wrote:I can not figure out, means, instead of this line (OutputStream outputStream = new FileOutputStream(new File("D:/test1" + i + ".jpg"));), which line should I write?

Did you read the FAQ article I took the time to link to?

because, I need to store images somewhere right?

No. Why does it need to be stored anywhere? All that needs to happen is for the image data to get sent to the HTML page. It doesn't need to be in a file for that.

and I know to display only one image in jsp by img tag, but how I display multiple images in jsp by img tag?

You display more than one image with more than one img tag. Or are you asking about something different?

Read the FAQ article. You seem to be under the impressions that image data can only come from a file. It doesn't need to come from a file. It doesn't matter where it comes from as long as the server sends the data to the HTML page generated by the JSP as a response to the image tag's request.

[sarojni agrwal]

This is not the case, I want to say that, I know , how to display one image from local disk D in jsp, and here the case is ,images retrieved from database, dynamically, so how is it possible, to give image tag each time ,it should be automatic right? the case is user put image and as user request the image stored in database, and then it should be on jsp, this is not the some specific static images..in static case multiple img tag should be fine, by giving name of each image.in my case there are lot images stored dynamically in database as per user request.

[Bear Bibeault]

So you meant different images in a single tag, not multiple images.

Still, the solution is the same. Your img tag references a servlet (not a file), providing enough data on the URL (request or path parameters) so that the servlet knows how to identify which image to fetch from the DB. The servlet then serves the image data as its response (setting appropriate headers).

[sarojni agrwal]

I want all images at once from database along with new one in one jsp page, means as user browse new image it saves at database, so I want that new one and all old images also at once in jsp page, so I tried here in jsp
by img tag:

<img src="http://localhost:8017/servletconfiganno/rt1" border="0" />

but I got one image only , how could I fetch all images in jsp page at once which is stored in database?

[Paul Clapham]

Yes, with an tag you get one image. If you want more than one image you need more than one tag.

If you want all the images in a server-side resource then your JSP needs to generate one tag for each of those images.

[Bear Bibeault]

I had already pointed that out before -- multiple images on an HTML page require multiple img tags. Remember that regardless of whether you are using JSP or not, your page ends up as an HTML page in the browser and so it must conform to all rules of HTML.

If that's not clear, perhaps reading this article will help.

[sarojni agrwal]

can you give the hint of that code by which , I could fetch all the images from database with only one tag, I can not figure it out by searching on google, I am stuck on it last 15 days, searching on net again and again, if you can tell me, it would be really good for me....

[Bear Bibeault]

sarojni agrwal wrote:can you give the hint of that code by which , I could fetch all the images from database with only one tag

You can't. That's what's been said again and again. If you want more than one image on an HTML page, you need more than one img tag.

[sarojni agrwal]

Here are I used two img tag:


<img src="http://localhost:8017/servletconfiganno/rt1" border="0" />
<img src="http://localhost:8017/servletconfiganno/rt1" border="0" />


but I got two same images on the browser. and one thing, I want to know that, how many tags should I use? (obviously there are no static images, not one or two not 50 images, it is dynamic images stored in database as per user request, when user browse image then it goes in database , then it should display on jsp, so how many tags should I use , in this case, when images are dynamic?)

[Paul Clapham]

Of course you got the same image twice, the URL is the same in both tags so it would naturally return the same image. If you want it to return different images, you'll need different URLs.

I suppose it still isn't obvious, so let me point out that the URL which requests an image is also going to have to say which image it's requesting. That's usually done by a URL parameter:

<img src="http://localhost:8017/servletconfiganno/rt1?image=2307" border="0" />

[sarojni agrwal]

what is this , image=2307? I can not understand , is this only image name or image id? if id , where should be image id in servlet?

[J. Kevin Robbins]

sarojni agrwal wrote:what is this , image=2307?

That is a request parameter for a GET request.

You seem to be struggling with some of the basics like parameters and img tags. I think you need to review some of the fundamentals. Try forgetting about jsp and servlets for now and just create an HTML page that displays images the way you want. Then you can work toward a jsp/servlet combination that will generate the html that you want.

Have you read the links that have been provided? Have you looked through our faqs and wikis?