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how to send and retrieve image along with text to and from database
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dwighttaylor
how to send and retrieve image along with text to and from database
0 Answer(s) a year and 3 months ago
Posted in : Java Beginners
0 Answer(s) a year and 3 months ago
Posted in : Java Beginners
im using app engine and i have two logics from different sources and i want to combine them. ive used the greeting example from app engine and i have a random image generator. im so stumped right now and i dont know how to combine the two. i want to take the random image along with the text and send it to another user for work. the application takes a random image for which code i have along with text that the user fills out based on the writing exercise about the random image and on the post it sends the data to another user. i hope im explaining this correctly
this is app engines greeting application
package guestbook;
import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.KeyFactory;
import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;
import java.io.IOException;
import java.util.Date;
import java.util.logging.Logger;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class SignGuestbookServlet extends HttpServlet {
private static final Logger log =
Logger.getLogger(SignGuestbookServlet.class.getName());
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
UserService userService = UserServiceFactory.getUserService();
User user = userService.getCurrentUser();
// We have one entity group per Guestbook with all Greetings residing
// in the same entity group as the Guestbook to which they belong.
// This lets us run an ancestor query to retrieve all Greetings for a
// given Guestbook. However, the write rate to each Guestbook should be
// limited to ~1/second.
String guestbookName = req.getParameter("guestbookName");
Key guestbookKey = KeyFactory.createKey("Guestbook", guestbookName);
String content = req.getParameter("content");
Date date = new Date();
Entity greeting = new Entity("Greeting", guestbookKey);
greeting.setProperty("user", user);
greeting.setProperty("date", date);
greeting.setProperty("content", content);
DatastoreService datastore =
DatastoreServiceFactory.getDatastoreService();
datastore.put(greeting);
resp.sendRedirect("/guestbook.jsp?guestbookName="
+ guestbookName);
}
}
//the guestbook.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="java.util.List" %>
<%@ page import="com.google.appengine.api.users.User" %>
<%@ page import="com.google.appengine.api.users.UserService" %>
<%@ page import="com.google.appengine.api.users.UserServiceFactory" %>
<%@ page import="com.google.appengine.api.datastore.DatastoreServiceFactory" %>
<%@ page import="com.google.appengine.api.datastore.DatastoreService" %>
<%@ page import="com.google.appengine.api.datastore.Query" %>
<%@ page import="com.google.appengine.api.datastore.Entity" %>
<%@ page import="com.google.appengine.api.datastore.FetchOptions" %>
<%@ page import="com.google.appengine.api.datastore.Key" %>
<%@ page import="com.google.appengine.api.datastore.KeyFactory" %>
<html>
<head>
<link type="text/css" rel="stylesheet" href="/stylesheets/main.css" />
</head>
<body>
<DIV id="container">
<DIV id="left">
<%
String guestbookName = request.getParameter("guestbookName");
if (guestbookName == null) {
guestbookName = "default";
}
UserService userService = UserServiceFactory.getUserService();
User user = userService.getCurrentUser();
if (user != null) {
%>
<p>Hello, <%= user.getNickname() %>! (You can
<a href="<%= userService.createLogoutURL(request.getRequestURI()) %>">sign out</a>.)</p>
<%
} else {
%>
<p>Hello!
<a href="<%= userService.createLoginURL(request.getRequestURI()) %>">Sign in</a>
to include your name with greetings you post.</p>
<%
}
%>
<%
DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
Key guestbookKey = KeyFactory.createKey("Guestbook", guestbookName);
// Run an ancestor query to ensure we see the most up-to-date
// view of the Greetings belonging to the selected Guestbook.
Query query = new Query("Greeting", guestbookKey).addSort("date", Query.SortDirection.DESCENDING);
List<Entity> greetings = datastore.prepare(query).asList(FetchOptions.Builder.withLimit(5));
if (greetings.isEmpty()) {
%>
<p>Guestbook '<%= guestbookName %>' has no messages.</p>
<%
} else {
%>
<p>Messages in Guestbook '<%= guestbookName %>'.</p>
<%
for (Entity greeting : greetings) {
if (greeting.getProperty("user") == null) {
%>
<p>An anonymous person wrote:</p>
<%
} else {
%>
<p><b><%= ((User) greeting.getProperty("user")).getNickname() %></b> wrote:</p>
<%
}
%>
<blockquote><%= greeting.getProperty("content") %></blockquote>
<%
}
}
%>
</DIV>
<DIV id="right">
<form action="/sign" method="post" style="width: 552px; ">
<div><textarea name="content" rows="3" cols="60"></textarea></div>
<div><input type="submit" value="Post Greeting"></div>
<input type="hidden" name="guestbookName" value="<%= guestbookName %>">
</form>
</DIV>
</DIV>
</body>
</html>
/*random image generator
<!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>Insert title here</title>
</head>
<style type="text/css">
html,body {
height:100%;
margin:0;
padding:0;
}
#imlocation {
width:100%;
height:100%;
border:3px double #999;
margin:2% auto;
}
#imlocation img {
width:100%;
height:100%;
}
</style>
<body>
<div id="imlocation" align="right">
<script type="text/javascript">
<!--
var imlocation = "images/forest/";
var currentdate = 0;
var image_number = 0;
function ImageArray (n) {
this.length = n;
for (var i =1; i <= n; i++) {
this[i] = ' '
}
}
image = new ImageArray(61)
image[0] = 'img0.jpg'
image[1] = 'img1.jpg'
image[2] = 'img2.jpg'
image[3] = 'img3.jpg'
image[4] = 'img4.jpg'
image[5] = 'img5.jpg'
image[6] = 'img6.jpg'
image[7] = 'img7.jpg'
image[8] = 'img8.jpg'
image[9] = 'img9.jpg'
image[10] = 'img10.jpg'
image[11] = 'img11.jpg'
image[12] = 'img12.jpg'
image[13] = 'img13.jpg'
image[14] = 'img14.jpg'
image[15] = 'img15.jpg'
image[16] = 'img16.jpg'
image[17] = 'img17.jpg'
image[18] = 'img18.jpg'
image[19] = 'img19.jpg'
image[20] = 'img20.jpg'
image[21] = 'img21.jpg'
image[22] = 'img22.jpg'
image[23] = 'img23.jpg'
image[24] = 'img24.jpg'
image[25] = 'img25.gif'
image[26] = 'img26.jpg'
image[27] = 'img27.jpg'
image[28] = 'img28.jpg'
image[29] = 'img29.jpg'
image[30] = 'img30.jpg'
image[31] = 'img31.jpg'
image[32] = 'img32.jpg'
image[33] = 'img33.jpg'
image[34] = 'img34.jpg'
image[35] = 'img35.jpg'
image[36] = 'img36.jpg'
image[37] = 'img37.jpg'
image[38] = 'img38.jpg'
image[39] = 'img39.jpg'
image[40] = 'img40.jpg'
image[41] = 'img41.jpg'
image[42] = 'img42.jpg'
image[43] = 'img43.jpg'
image[44] = 'img44.jpg'
image[45] = 'img45.jpg'
image[46] = 'img46.jpg'
image[47] = 'img47.jpg'
image[48] = 'img48.jpg'
image[49] = 'img49.jpg'
image[50] = 'img50.jpg'
image[51] = 'img51.jpg'
image[52] = 'img52.jpg'
image[53] = 'img53.jpg'
image[54] = 'img54.jpg'
image[55] = 'img55.jpg'
image[56] = 'img56.jpg'
image[57] = 'img57.jpg'
image[58] = 'img58.jpg'
image[59] = 'img59.jpg'
image[60] = 'img60.jpg'
var rand = 60/image.length
function randomimage() {
currentdate = new Date()
image_number = currentdate.getSeconds()
image_number = Math.floor(image_number/rand)
return(image[image_number])
}
document.write("<img src='" + imlocation + randomimage()+ "'>");
//-->
</script>
</div>
</body>
</html>
what i want it to do is send the random image along with the text to the database if the user presses the button. thanks im hoping for an answer
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