how to upload and download images in java?

what is the code for uploading and downloading images in java? how do I make a photo gallery through JSP? I want to create a photo gallery for each user which can be viewed by all users but can be updated and deleted by the creator. Please give me suggestions.

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March 14, 2011 at 3:17 PM

Upload and Download images:

1)page.jsp:

<%@ page language="java" %>
<HTML>
<HEAD><TITLE>Display file upload form to the user</TITLE></HEAD>
<BODY> <FORM ENCTYPE="multipart/form-data" ACTION="upload.jsp" METHOD=POST>
<br><br><br>
<center>
<table border="0" bgcolor=#ccFDDEE>
<tr>
<center>
<td colspan="2" align="center"><B>UPLOAD THE FILE</B><center></td>
</tr>
<tr>
<td colspan="2" align="center"> </td>
</tr>
<tr>
<td><b>Choose the file To Upload:</b></td>
<td><INPUT NAME="file" TYPE="file"></td>
</tr>
<tr>
<td colspan="2" align="center"> </td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" value="Send File"> </td>
</tr>
<table>
</center>
</FORM>
</BODY>
</HTML>

2)upload.jsp:

<%@ page import="java.io.*" %>
<%@ page import="java.sql.*" %>
<%@ page import="java.util.zip.*"%>
<%
String saveFile="";
String contentType = request.getContentType();
if((contentType != null)&&(contentType.indexOf("multipart/form-data") >= 0)){
DataInputStream in = new DataInputStream(request.getInputStream());
int formDataLength = request.getContentLength();
byte dataBytes[] = new byte[formDataLength];
int byteRead = 0;
int totalBytesRead = 0;
while(totalBytesRead < formDataLength){
byteRead = in.read(dataBytes, totalBytesRead,formDataLength);
totalBytesRead += byteRead;
}
String file = new String(dataBytes);
saveFile = file.substring(file.indexOf("filename=\"") + 10);
saveFile = saveFile.substring(0, saveFile.indexOf("\n"));
saveFile = saveFile.substring(saveFile.lastIndexOf("\\") + 1,saveFile.indexOf("\""));
int lastIndex = contentType.lastIndexOf("=");
String boundary = contentType.substring(lastIndex + 1,contentType.length());
int pos;
pos = file.indexOf("filename=\"");
pos = file.indexOf("\n", pos) + 1;
pos = file.indexOf("\n", pos) + 1;
pos = file.indexOf("\n", pos) + 1;
int boundaryLocation = file.indexOf(boundary, pos) - 4;
int startPos = ((file.substring(0, pos)).getBytes()).length;
int endPos = ((file.substring(0, boundaryLocation)).getBytes()).length;
File ff = new File(saveFile);
FileOutputStream fileOut = new FileOutputStream(ff);
fileOut.write(dataBytes, startPos, (endPos - startPos));
fileOut.flush();
fileOut.close();
%><Br><table border="2"><tr><td><b>You have successfully upload the file:</b>
<% out.println(saveFile);%></td></tr></table>
<%
Connection connection = null;
String connectionURL = "jdbc:mysql://localhost:3306/test";
ResultSet rs = null;
PreparedStatement psmnt = null;
FileInputStream fis;
try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(connectionURL, "root", "root");
File f = new File(saveFile);
psmnt = connection.prepareStatement("insert into image(images) values(?)");
fis = new FileInputStream(f);
psmnt.setBinaryStream(1, (InputStream)fis, (int)(f.length()));
int s = psmnt.executeUpdate();
if(s>0){
System.out.println("Uploaded successfully !");
}
else{
System.out.println("Error!");
}
}
catch(Exception e){e.printStackTrace();}
}
%>
<a href="showimages.jsp">Download Image</a>

March 14, 2011 at 3:18 PM

3)showimages.jsp:

<%@ page import="java.sql.*,java.io.*,java.util.*" %> 
<HTML>
 <HEAD>
  <TITLE>Download Images</TITLE>
  </HEAD>

 <BODY>
   <br><br>
  <table align="center" border=0 width="200px">
   <tr>
    <td colspan=2 align="center"><b>Download Images</b></td>
  </tr>
  <tr><td colspan=2>&nbsp;</td></tr>
  <%

  String connectionURL = "jdbc:mysql://localhost:3306/test";
  Connection con=null;
  try{      
    Class.forName("com.mysql.jdbc.Driver").newInstance();
    con=DriverManager.getConnection(connectionURL,"root","root");
    Statement stmt=con.createStatement();
    String strQuery = "select id from image";
    ResultSet rs = stmt.executeQuery(strQuery);
    while(rs.next())
    {

      %>
      <tr style="background-color:#efefef;">
      <td><%=rs.getInt(1)%></td>
      <td>
<a href="images.jsp?imgid=<%=rs.getInt(1)%>">
<img src="images.jsp?imgid=<%=rs.getInt(1)%>" width="50" height="50">
</a></td>
      </tr>
      <%
    }
    rs.close();
    con.close();
    stmt.close();
  }
  catch(Exception e)
  {
    e.getMessage();
  }
  %>
 </table>
  </BODY>
</HTML>

4)images.jsp:

<%@ page import="java.sql.*,java.io.*,java.util.*" %> 
<%
String connectionURL = "jdbc:mysql://localhost:3306/test";
if(request.getParameter("imgid")!=null && request.getParameter("imgid")!="")
{
  int id =  Integer.parseInt(request.getParameter("imgid"));

  String filename = "image"+id+".jpg";
  Connection con=null;
  try{      
    Class.forName("com.mysql.jdbc.Driver").newInstance();
    con=DriverManager.getConnection(connectionURL,"root","root");      
    Statement st1=con.createStatement();
    String strQuery = "select images from image where id="+id;

    ResultSet rs1 = st1.executeQuery(strQuery);

    String imgLen="";
    if(rs1.next()){
      imgLen = rs1.getString(1);
       }  
    rs1 = st1.executeQuery(strQuery);
    if(rs1.next()){
      int len = imgLen.length();
      byte [] rb = new byte[len];
      InputStream readImg = rs1.getBinaryStream(1);
      int index=readImg.read(rb, 0, len);  
      st1.close();
      response.reset();
      response.setContentType("image/jpg");
      response.setHeader("Content-disposition","attachment; filename=" +filename);
      response.getOutputStream().write(rb,0,len); 
      response.getOutputStream().flush();        
    }
  }
  catch (Exception e){
    e.printStackTrace();
  }
}
%>









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