VideoServlet

HtmlVideoServlet.java

package org.magnum.mobilecloud.video.servlet;

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

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

/**
 * Adds an html form to capture and display video metadata. 
 * Allows clients to send HTTP POST
 * requests with videos that are stored in memory using a list.
 * Clients can send HTTP GET requests to receive a 
 * listing of the videos that have been sent to the servlet
 * so far. Stopping the servlet will cause it to lose the history
 * of videos that have been sent to it because they are stored
 * in memory.
 * 
 * @author jules
 * @author Anonymous
 *
 */
public class HtmlVideoServlet extends HttpServlet // Servlets should inherit HttpServlet
{
	private static final long serialVersionUID = 1L;
	
	public static final String VIDEO_ADDED = "Video added.";
    // An in-memory list that the servlet uses to store the
    // videos that are sent to it by clients
    private List<Video> videos = new java.util.concurrent.CopyOnWriteArrayList<Video>();
    
    protected void processRequest(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {

        // Make sure and set the content-type header so that the client
        // can properly (and securely!) display the content that you send
        // back
        resp.setContentType("text/html");

        // This PrintWriter allows us to write data to the HTTP 
        // response body that is going to be sent to the client.
        PrintWriter sendToClient = resp.getWriter();
        
        // UI form
        sendToClient.write(
            "<form name='formvideo' method='POST' target='_self'>" +
            "<fieldset><legend>Video Data</legend>" +
            "<table><tr>" +
            "<td><label for='name'>Name:&nbsp;</label></td>" +
            "<td><input type='text' name='name' id='name' size='64' maxlength='64' /></td>" +
            "</tr><tr>" +
            "<td><label for='url'>URL:&nbsp;</label></td>" +
            "<td><input type='text' name='url' id='url' size='64' maxlength='256' /></td>" +
            "</tr><tr>" +
            "<td><label for='duration'>Duration:&nbsp;</label></td>" +
            "<td><input type='text' name='duration' id='duration' size='16' maxlength='16' /></td>" +
            "</tr><tr>" +
            "<td style='text-align: right;' colspan=2><input type='submit' value='Add Video' /></td>" +
            "</tr></table></fieldset></form>");
        
        // Loop through all of the stored videos and print them out
        // for the client to see.
        for (Video v : this.videos) {
            
            // For each video, write its name and URL into the HTTP
            // response body
            sendToClient.write(v.getName() + " : " + v.getUrl() + " (" + v.getDuration() + ")<br />");
        }
        sendToClient.write("</body></html>");
    }
    
    /**
     * This method processes all of the HTTP GET requests routed to the
     * servlet by the web container. This method loops through the lists
     * of videos that have been sent to it and generates a plain/text 
     * list of the videos that is sent back to the client.
     * 
     */
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
    	resp.getWriter().write("<html><body>");
        processRequest(req, resp);
    }

    /**
     * This method handles all HTTP POST requests that are routed to the
     * servlet by the web container.
     * 
     * Sending a post to the servlet with 'name', 'duration', and 'url' 
     * parameters causes a new video to be created and added to the list of 
     * videos. 
     * 
     * If the client fails to send one of these parameters, the servlet generates 
     * an HTTP error 400 (Bad request) response indicating that a required request
     * parameter was missing.
     */
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        
        // First, extract the HTTP request parameters that we are expecting
        // from either the URL query string or the url encoded form body
        String name = req.getParameter("name");
        String url = req.getParameter("url");
        String durationStr = req.getParameter("duration");
        
        // Check that the duration parameter provided by the client
        // is actually a number
        long duration = -1;
        try{
            duration = Long.parseLong(durationStr);
        }catch(NumberFormatException e){
            // The client sent us a duration value that wasn't a number!
        }

        // Now, the servlet has to look at each request parameter that the
        // client was expected to provide and make sure that it isn't null,
        // empty, etc.
        if (name == null || url == null || durationStr == null
                || name.trim().length() < 1 || url.trim().length() < 10
                || durationStr.trim().length() < 1
                || duration <= 0) {
            
            // If the parameters pass our basic validation, we need to 
            // send an HTTP 400 Bad Request to the client and give it
            // a hint as to what it got wrong.
            resp.setContentType("text/html");
            resp.sendError(400, "Missing ['name','duration','url'].");
        } 
        else {
            // It looks like the client provided all of the data that
            // we need, use that data to construct a new Video object
            Video v = new Video(name, url, duration);
            
            // Add the video to our in-memory list of videos
            videos.add(v);
            
            // Let the client know that we successfully added the video
            // by writing a message into the HTTP response body
            resp.getWriter().write("<html><body>" + VIDEO_ADDED);
            
            processRequest(req, resp);
        }
    }
}

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package org.magnum.mobilecloud.video.servlet;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.List;

/**

* Adds an html form to capture and display video metadata.

* Allows clients to send HTTP POST

* requests with videos that are stored in memory using a list.

* Clients can send HTTP GET requests to receive a

* listing of the videos that have been sent to the servlet

* so far. Stopping the servlet will cause it to lose the history

* of videos that have been sent to it because they are stored

* in memory.

* @author jules

* @author Anonymous

public class HtmlVideoServlet extends HttpServlet // Servlets should inherit HttpServlet

{

private static final long serialVersionUID = 1L;

public static final String VIDEO_ADDED = "Video added.";

// An in-memory list that the servlet uses to store the

// videos that are sent to it by clients

private List<Video> videos = new java.util.concurrent.CopyOnWriteArrayList<Video>();

protected void processRequest(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

// Make sure and set the content-type header so that the client

// can properly (and securely!) display the content that you send

// back

resp.setContentType("text/html");

// This PrintWriter allows us to write data to the HTTP

// response body that is going to be sent to the client.

PrintWriter sendToClient = resp.getWriter();

// UI form

sendToClient.write(

"<form name='formvideo' method='POST' target='_self'>" +

"<fieldset><legend>Video Data</legend>" +

"<table><tr>" +

"<td><label for='name'>Name: </label></td>" +

"<td><input type='text' name='name' id='name' size='64' maxlength='64' /></td>" +

"</tr><tr>" +

"<td><label for='url'>URL: </label></td>" +

"<td><input type='text' name='url' id='url' size='64' maxlength='256' /></td>" +

"</tr><tr>" +

"<td><label for='duration'>Duration: </label></td>" +

"<td><input type='text' name='duration' id='duration' size='16' maxlength='16' /></td>" +

"</tr><tr>" +

"<td style='text-align: right;' colspan=2><input type='submit' value='Add Video' /></td>" +

"</tr></table></fieldset></form>");

// Loop through all of the stored videos and print them out

// for the client to see.

for (Video v : this.videos) {

// For each video, write its name and URL into the HTTP

// response body

sendToClient.write(v.getName() + " : " + v.getUrl() + " (" + v.getDuration() + ")<br />");

}

sendToClient.write("</body></html>");

}

/**

* This method processes all of the HTTP GET requests routed to the

* servlet by the web container. This method loops through the lists

* of videos that have been sent to it and generates a plain/text

* list of the videos that is sent back to the client.

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

resp.getWriter().write("<html><body>");

processRequest(req, resp);

}

/**

* This method handles all HTTP POST requests that are routed to the

* servlet by the web container.

* Sending a post to the servlet with 'name', 'duration', and 'url'

* parameters causes a new video to be created and added to the list of

* videos.

* If the client fails to send one of these parameters, the servlet generates

* an HTTP error 400 (Bad request) response indicating that a required request

* parameter was missing.

@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

// First, extract the HTTP request parameters that we are expecting

// from either the URL query string or the url encoded form body

String name = req.getParameter("name");

String url = req.getParameter("url");

String durationStr = req.getParameter("duration");

// Check that the duration parameter provided by the client

// is actually a number

long duration = -1;

try{

duration = Long.parseLong(durationStr);

}catch(NumberFormatException e){

// The client sent us a duration value that wasn't a number!

}

// Now, the servlet has to look at each request parameter that the

// client was expected to provide and make sure that it isn't null,

// empty, etc.

if (name == null || url == null || durationStr == null

|| name.trim().length() < 1 || url.trim().length() < 10

|| durationStr.trim().length() < 1

|| duration <= 0) {

// If the parameters pass our basic validation, we need to

// send an HTTP 400 Bad Request to the client and give it

// a hint as to what it got wrong.

resp.setContentType("text/html");

resp.sendError(400, "Missing ['name','duration','url'].");

}

else {

// It looks like the client provided all of the data that

// we need, use that data to construct a new Video object

Video v = new Video(name, url, duration);

// Add the video to our in-memory list of videos

videos.add(v);

// Let the client know that we successfully added the video

// by writing a message into the HTTP response body

resp.getWriter().write("<html><body>" + VIDEO_ADDED);

processRequest(req, resp);

}

Video.java

package org.magnum.mobilecloud.video.servlet;

/**
 * A simple object to represent a video and its URL for viewing.
 * 
 * @author jules
 * 
 */
public class Video {

	private String name;
	private String url;
	private long duration;

	public Video(String name, String url, long duration) {
		super();
		this.name = name;
		this.url = url;
		this.duration = duration;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	public long getDuration() {
		return duration;
	}

	public void setDuration(long duration) {
		this.duration = duration;
	}

}

package org.magnum.mobilecloud.video.servlet;

/**

* A simple object to represent a video and its URL for viewing.

* @author jules

public class Video {

private String name;

private String url;

private long duration;

public Video(String name, String url, long duration) {

super();

this.name = name;

this.url = url;

this.duration = duration;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getUrl() {

return url;

}

public void setUrl(String url) {

this.url = url;

}

public long getDuration() {

return duration;

}

public void setDuration(long duration) {

this.duration = duration;

}

VideoServlet.java

package org.magnum.mobilecloud.video.servlet;

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

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

/**
 * This simple VideoServlet allows clients to send HTTP POST
 * requests with videos that are stored in memory using a list.
 * Clients can send HTTP GET requests to receive a plain/test
 * listing of the videos that have been sent to the servlet
 * so far. Stopping the servlet will cause it to lose the history
 * of videos that have been sent to it because they are stored
 * in memory.
 * 
 * @author jules
 *
 */
public class VideoServlet extends HttpServlet // Servlets should inherit HttpServlet
{

	public static final String VIDEO_ADDED = "Video added.";
	// An in-memory list that the servlet uses to store the
	// videos that are sent to it by clients
	private List<Video> videos = new ArrayList<Video>();

	/**
	 * This method processes all of the HTTP GET requests routed to the
	 * servlet by the web container. This method loops through the lists
	 * of videos that have been sent to it and generates a plain/text 
	 * list of the videos that is sent back to the client.
	 * 
	 */
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {

		// Make sure and set the content-type header so that the client
		// can properly (and securely!) display the content that you send
		// back
		resp.setContentType("text/plain");

		// This PrintWriter allows us to write data to the HTTP 
		// response body that is going to be sent to the client.
		PrintWriter sendToClient = resp.getWriter();
		
		// Loop through all of the stored videos and print them out
		// for the client to see.
		for (Video v : this.videos) {
			
			// For each video, write its name and URL into the HTTP
			// response body
			sendToClient.write(v.getName() + " : " + v.getUrl() + "\n");
		}

	}

	/**
	 * This method handles all HTTP POST requests that are routed to the
	 * servlet by the web container.
	 * 
	 * Sending a post to the servlet with 'name', 'duration', and 'url' 
	 * parameters causes a new video to be created and added to the list of 
	 * videos. 
	 * 
	 * If the client fails to send one of these parameters, the servlet generates 
	 * an HTTP error 400 (Bad request) response indicating that a required request
	 * parameter was missing.
	 */
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		
		// First, extract the HTTP request parameters that we are expecting
		// from either the URL query string or the url encoded form body
		String name = req.getParameter("name");
		String url = req.getParameter("url");
		String durationStr = req.getParameter("duration");
		
		// Check that the duration parameter provided by the client
		// is actually a number
		long duration = -1;
		try{
			duration = Long.parseLong(durationStr);
		}catch(NumberFormatException e){
			// The client sent us a duration value that wasn't a number!
		}

		// Make sure and set the content-type header so that the client knows
		// how to interpret the data that gets sent back
		resp.setContentType("text/plain");

		// Now, the servlet has to look at each request parameter that the
		// client was expected to provide and make sure that it isn't null,
		// empty, etc.
		if (name == null || url == null || durationStr == null
				|| name.trim().length() < 1 || url.trim().length() < 10
				|| durationStr.trim().length() < 1
				|| duration <= 0) {
			
			// If the parameters pass our basic validation, we need to 
			// send an HTTP 400 Bad Request to the client and give it
			// a hint as to what it got wrong.
			resp.sendError(400, "Missing ['name','duration','url'].");
		} 
		else {
			// It looks like the client provided all of the data that
			// we need, use that data to construct a new Video object
			Video v = new Video(name, url, duration);
			
			// Add the video to our in-memory list of videos
			videos.add(v);
			
			// Let the client know that we successfully added the video
			// by writing a message into the HTTP response body
			resp.getWriter().write(VIDEO_ADDED);
		}
	}

}

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package org.magnum.mobilecloud.video.servlet;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.List;

/**

* This simple VideoServlet allows clients to send HTTP POST

* requests with videos that are stored in memory using a list.

* Clients can send HTTP GET requests to receive a plain/test

* listing of the videos that have been sent to the servlet

* so far. Stopping the servlet will cause it to lose the history

* of videos that have been sent to it because they are stored

* in memory.

* @author jules

public class VideoServlet extends HttpServlet // Servlets should inherit HttpServlet

{

public static final String VIDEO_ADDED = "Video added.";

// An in-memory list that the servlet uses to store the

// videos that are sent to it by clients

private List<Video> videos = new ArrayList<Video>();

/**

* This method processes all of the HTTP GET requests routed to the

* servlet by the web container. This method loops through the lists

* of videos that have been sent to it and generates a plain/text

* list of the videos that is sent back to the client.

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

// Make sure and set the content-type header so that the client

// can properly (and securely!) display the content that you send

// back

resp.setContentType("text/plain");

// This PrintWriter allows us to write data to the HTTP

// response body that is going to be sent to the client.

PrintWriter sendToClient = resp.getWriter();

// Loop through all of the stored videos and print them out

// for the client to see.

for (Video v : this.videos) {

// For each video, write its name and URL into the HTTP

// response body

sendToClient.write(v.getName() + " : " + v.getUrl() + "\n");

}

/**

* This method handles all HTTP POST requests that are routed to the

* servlet by the web container.

* Sending a post to the servlet with 'name', 'duration', and 'url'

* parameters causes a new video to be created and added to the list of

* videos.

* If the client fails to send one of these parameters, the servlet generates

* an HTTP error 400 (Bad request) response indicating that a required request

* parameter was missing.

@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

// First, extract the HTTP request parameters that we are expecting

// from either the URL query string or the url encoded form body

String name = req.getParameter("name");

String url = req.getParameter("url");

String durationStr = req.getParameter("duration");

// Check that the duration parameter provided by the client

// is actually a number

long duration = -1;

try{

duration = Long.parseLong(durationStr);

}catch(NumberFormatException e){

// The client sent us a duration value that wasn't a number!

}

// Make sure and set the content-type header so that the client knows

// how to interpret the data that gets sent back

resp.setContentType("text/plain");

// Now, the servlet has to look at each request parameter that the

// client was expected to provide and make sure that it isn't null,

// empty, etc.

if (name == null || url == null || durationStr == null

|| name.trim().length() < 1 || url.trim().length() < 10

|| durationStr.trim().length() < 1

|| duration <= 0) {

// If the parameters pass our basic validation, we need to

// send an HTTP 400 Bad Request to the client and give it

// a hint as to what it got wrong.

resp.sendError(400, "Missing ['name','duration','url'].");

}

else {

// It looks like the client provided all of the data that

// we need, use that data to construct a new Video object

Video v = new Video(name, url, duration);

// Add the video to our in-memory list of videos

videos.add(v);

// Let the client know that we successfully added the video

// by writing a message into the HTTP response body

resp.getWriter().write(VIDEO_ADDED);

}

web.xml

<?xml version="1.0" encoding="ISO-8859-1" ?>

<!-- The web.xml file provides basic information to the web container on 
	how to load your servlets into the container and which requests should be 
	routed to each servlet. -->
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
	version="2.4">

	<display-name>Video Application</display-name>
	<description>
		This is an application that will extract parameters and validate them.
		It allows clients to send the metadata for Videos.
	</description>

	<!-- This set of directives tells the web application container about our 
		servlet class so that it is loaded by the container -->
	<servlet>
		<servlet-name>VideoServlet</servlet-name>
		<servlet-class>org.magnum.mobilecloud.video.servlet.VideoServlet
		</servlet-class>
	</servlet>

	<servlet>
		<servlet-name>HtmlVideoServlet</servlet-name>
		<servlet-class>org.magnum.mobilecloud.video.servlet.HtmlVideoServlet
		</servlet-class>
	</servlet>

	<!-- this set of directives tells the web application container which requests 
		should be routed to our servlet. In this case, any request to the path '/video' 
		will be routed to the servlet. You can use wildcards for path matching. For 
		example, '/video/**' would match any sub path of '/video/', such as '/video/foo' 
		and '/video/bar' -->
	<servlet-mapping>
		<servlet-name>VideoServlet</servlet-name>
		<url-pattern>/video</url-pattern>
	</servlet-mapping>

	<servlet-mapping>
		<servlet-name>HtmlVideoServlet</servlet-name>
		<url-pattern>/view/video</url-pattern>
	</servlet-mapping>
</web-app>

<?xml version="1.0" encoding="ISO-8859-1" ?>

<!-- The web.xml file provides basic information to the web container on

how to load your servlets into the container and which requests should be

routed to each servlet. -->

<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"

version="2.4">

<display-name>Video Application</display-name>

This is an application that will extract parameters and validate them.

It allows clients to send the metadata for Videos.

</description>

<!-- This set of directives tells the web application container about our

servlet class so that it is loaded by the container -->

<servlet-name>VideoServlet</servlet-name>

<servlet-class>org.magnum.mobilecloud.video.servlet.VideoServlet

</servlet-class>

</servlet>

<servlet-name>HtmlVideoServlet</servlet-name>

<servlet-class>org.magnum.mobilecloud.video.servlet.HtmlVideoServlet

</servlet-class>

</servlet>

<!-- this set of directives tells the web application container which requests

should be routed to our servlet. In this case, any request to the path '/video'

will be routed to the servlet. You can use wildcards for path matching. For

example, '/video/**' would match any sub path of '/video/', such as '/video/foo'

and '/video/bar' -->

<servlet-mapping>

<servlet-name>VideoServlet</servlet-name>

<url-pattern>/video</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>HtmlVideoServlet</servlet-name>

<url-pattern>/view/video</url-pattern>

</servlet-mapping>

</web-app>