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I'm stuck between studying PHP and Java Servlets.
Is there any compelling reason to chose any over the other?
(I understand PHP is the most commonly used back end language)
I only have one semester to learn, and i can only chose one.
Any advice you would offer me given i have a java background.
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mainadmn wrote: Is there any compelling reason to chose any over the other? No.
mainadmn wrote: Any advice you would offer me given i have a java background. Choose the one that looks easiest to understand.
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so apart from that there's nothing to do with compatibility?
slow loading?
or anything else similar?
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Well, apart from the fact that you said you have only one semester to learn it, there was nothing in your question that would help make a decision. Whichever route you choose it is likely to be useful in giving you more experience of working with different systems. Only when you are applying for paid employment do the specific platforms and languages become important.
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if u have a java background no need of learning php..and php is not a back end lang
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I would like to track client mac address when he/she is browsing my website.
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Do you mean by JavaScript? That's not Java.
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Hi, I'm doing my school project called 81 cards puzzle game using java. But I have no idea how to do. Can anyone have any reference source code for some kinda project like that? I don't know how to write to represent that 81 cards in java class? Please someone help quickly.
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I am having trouble in only the last line of code. (I think!) The first label prompts the user for their name. If they click the button, then it will change the second label to read "Hello, (username)!" Can anyone give me some pointers?
import java.applet.Applet;
import java.awt.Button;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class Greeting extends Applet implements ActionListener {
JLabel labelName = new JLabel("Please enter your name.");
JTextField textField = new JTextField(20);
Button button = new Button("GREET");
JLabel labelResult = new JLabel("Result goes here.");
String userResult = "";
public void init() {
setSize(500, 500);
setBackground(Color.yellow);
add(labelName);
add(textField);
add(button);
add(labelResult);
button.addActionListener(this);
}
public String getText() {
return userResult;
}
public void setName(String result){
userResult = result;
}
public void actionPerformed(ActionEvent event) {
if (event.getSource() == button) {
labelResult.setText("Hello, " + userResult);
}
}
}
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You have not included any code to get the user's name from textField . And your getter and setter are mismatched. You need something like:
public String getName() {
return userResult;
}
public void setName(String result){
userResult = result;
}
public void actionPerformed(ActionEvent event) {
if (event.getSource() == button) {
setName(textField.toString());
labelResult.setText("Hello, " + getName());
}
}
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someone told me applets are dead?
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Someone told me that Leslie was alive.
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I cannot figure out what I am doing wrong. I just don't feel like I'm ever going to understand all of this. My prompts and loop are working fine. However, I am not getting any output. I'm sure it's a fairly simple thing, but I just don't see it so I can't know for sure what I need to fix. I have watched all the videos and looked through my textbook and the internet, but I need someone to "dumb" it down for me, I guess. Thank you, in advance, for your patience and help.
import java.util.Scanner;
public class StudentInfoTest
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
String answer = "";
double GPA = 0.0;
StudentInfo info = new StudentInfo(null, 0, 0);
System.out.print("Enter student name: ");
String name = input.nextLine();
info.setName(name);
do
{
System.out.print("Enter class credits: ");
String credits = input.nextLine();
System.out.print("Enter letter grade: ");
String grade = input.nextLine();
System.out.print("Add another class? (Y or N): ");
answer = input.nextLine();
}
while (answer.equals("Y"));
System.out.printf(name + ", Your GPA is %.2f/n.", GPA);
}
}
public class StudentInfo {
private String studentName;
private double totalPoints;
private double totalCredits;
public StudentInfo(String name, double points, double credits)
{
studentName = name;
totalPoints = points;
totalCredits = credits;
}
public void setName(String name)
{
studentName = name;
}
public String getName()
{
return studentName;
}
public void addClass(double credits, String grade)
{
double points = 0.0;
if(grade == "A" | grade == "a")
points = 4.0;
if(grade == "B" | grade == "b")
points = 3.0;
if(grade == "C" | grade == "c")
points = 2.0;
if(grade == "D" | grade == "d")
points = 1.0;
if(grade == "F" | grade == "f")
points = 0.0;
totalCredits += credits;
totalPoints += (points * credits);
}
public double getGPA(double totalPoints, double totalCredits)
{
double GPA = 0.0;
GPA = totalPoints / totalCredits;
return GPA;
}
public static void displayStudent(String name, double GPA)
{
}
}
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If I understand your question correctly, you never get the correct GPA? If that is the case, it looks like you never call getGPA , you only use the initial (0.0) value.
So instead of
System.out.printf(name + ", Your GPA is %.2f/n.", GPA);
Should you have
System.out.printf(name + ", Your GPA is %.2f/n.", info.getGPA());
The same applies to credits and grade. You never seem to call addClass
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I guess I don't understand what I am supposed to do to call them...
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Have a look at the example I wrote. The same way, after you have got the input from the user call the addClass method with your variables...
Something like
info.addClass(credits, grade);
Just keep in mind that the next thing you should implement is proper conversion between the data types (from string to double)
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I have a 64-bit Windows 8.1
The issue is that all the JRE installers version 8 update 45 for either x86 or x64 platform stop silently at the very beginning . Please note that there are no error messages appearing in messagebox form or in system event logs. Clean reboot along with all antivirus shutdown did not help. In fact I have no idea where to go further.
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moonwalker72067 wrote: In fact I have no idea where to go further. Without more information, neither do we. Unless you can find any install logs with some error details it is anyone's guess what the issue is. You should back to the Oracle download site and ask there.
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can we store a continuous real time console output into a text file in java. if yes then how we can append the next console output into the same text file.
can anybody tell me the code for that.
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I am still working on this myself, but I am kind of just needing a little reassurance that I am on the right track or a push in the right direction. This is all really new to me, and I'm honestly getting a little overwhelmed. Thank you!
You must create a sales tracking program named SalesTracking.java. This program will use arrays to store and process monthly sales as well as compute average yearly sales, total sales for the year, and which month had the highest sales and which month had the lowest sales. You should use parallel arrays. Your first array (monthArray) should be initialized with all of the months. This array should have 12 locations of course. Your other array should be named monthlySales. Like your monthArray, this array should be 12 locations that store the amount of sales for each month.
The program should prompt the user for the sales for each month starting with January. The arrays (monthlySales and monthArray) should be created in main and passed to the methods as needed. Your program should have methods that do the following.
getSales(monthArray, monthlySales): This method receives the monthArray and monthlySales arrays as arguments. It prompts the users for the sale for each month. This amount should be stored and returned into the corresponding location in the monthlySales array. For example, January sales should be stored in the first location, February sales should be stored in the second location, and so forth.
computeTotalSales(monthlySales): This method receives the monthly sales array as an argument and returns the total sales of the year.
computeAverageSales(monthlySales): This method receives the monthly sales array as an argument and returns the average sales for the year.
computeHighestMonth(monthlySales): This method receives the monthly sales array as an argument. This method will search and compare the values of the monthly sales array for the highest value. The method will return the index(or location in the array) of the month with the highest value.
computeLowestMonth(monthlySales): This method receives the monthly sales array as an argument. This method will search and compare the values of the monthly sales array for the lowest value. The method will return the index (or location in the array) of the month with the lowest value.
displaySaleInfo(totalSales, averageSales, highestMonth, highestSales, lowestMonth, lowestSales): This method will receive the total yearly sales, average monthly sale, the month with the highest sales, as well as the sales for that month and the month with the lowest sales. This method will display all of the data it received as arguments.
All methods should be STATIC therefore no object will need to be instantiated to call them. All methods must be called from the main method. Sales amounts should be rounded to two decimal places.
public class SalesTracking
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
<pre>
double totalSales = 0;
double averageSales = 0;
double highestMonth = 0;
double lowestMonth = 0;
double highestSales = 0;
double lowestSales = 0;
total = computeTotalSales(monthlySales);
average = computeAverageSales(monthlySales);
highest = computeHighestMonth(monthlySales);
lowest = computeLowestMonth(monthlySales);
String[] monthArray = {"JANUARY", "FEBRUARY", "MARCH", "APRIL", "MAY", "JUNE", "JULY",
"AUGUST", "SEPTEMBER", "OCTOBER", "NOVEMBER", "DECEMBER"};
for (String month : monthArray);
{
System.out.println(Arrays.toString(monthArray));
}
double[] monthlySales = new double[12];
for (int index = 0; index < monthlySales.length; index++)
{
System.out.print("Enter the monthly sales: ");
monthlySales[index] = Double.parseDouble(input.nextLine());
}
System.out.println("The monthly sales are: ");
for (int index = 0; index < monthlySales.length; index++)
{
System.out.println(monthlySales[index]);
}
}
public static void getSales (String monthArray, double monthlySales)
{
}
//This method receives the monthlySales array and returns the total yearly sales.
public static double computeTotalSales(double[] monthlySales)
{
double total = 0.0;
for(double index = 0; index < monthlySales.length; index++)
{
total += monthlySales[(int) index];
}
return total;
}
//This method receives the monthlySales array and returns the average yearly sales.
public static double computeAverageSales (double[] monthlySales)
{
double averageSales = 0;
double totalSales = 0;
averageSales = totalSales/monthlySales.length;
return averageSales;
}
//This method receives the monthlySales array and returns the index (or location)
//of the month with the highest value.
public static double computeHighestMonth (double[] monthlySales)
{
double highestMonth = monthlySales[0];
for (double index = 1; index < monthlySales.length; index++)
{if(monthlySales[(int) index] > highestMonth)
{
highestMonth = monthlySales[(int) index];
}
}
return highestMonth;
}
//This method receives the monthlySales array and returns the index (or location)
//of the month with the lowest value.
public static double computeLowestMonth (double[] monthlySales)
{
double lowestMonth = monthlySales[0];
for (double index = 1; index < monthlySales.length; index++)
{if(monthlySales[(int) index] < lowestMonth)
{
lowestMonth = monthlySales[(int) index];
}
}
return lowestMonth;
}
//The method receives the total yearly sales, average monthly sales, the month
//with the highest sale and its sales, and the month with the lowest sales and
//its sales and displays all of the data.
public static double displaySaleInfo (double totalSales, double averageSales,
double highestMonth, double highestSales, double lowestMonth, double
lowestSales)
{
System.out.print("The total sales are: " + totalSales);
System.out.print("The average sales are: " + averageSales);
System.out.print("The month with the highest sales is: " + highestMonth);
System.out.print("The highest sales for that month is: " + highestSales);
System.out.print("The month with the lowest sales is: " + lowestMonth);
System.out.print("The lowest sales for that month is: " + lowestSales);
return lowestSales;
}
//This bracket ends the class.
modified 12-Jul-15 3:54am.
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So what is the question? If you want to know if the code is working then you need to feed it with some test data and check the results. If you have specific areas where it is not working then you need to explain the details so we can offer suggestions.
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Please in course of my search for a java web application that uses a Webcam to make a stream of video clip and with the capability of snapping image in course of the video streaming process I came across this link: http://www.webdesignermag.co.uk/capture-webcam-video-with-html5/
I realized that the program suits my need but it does not have a way of programmatically giving the video and or the captured image a unique name and a directory where they can be saved respectively. Therefore I tried to modify the index.jsp, web.xml and the ImageServlet.java codes to be able to programmatically give the video and the captured image a unique name and consequently save them in the C:/WebcamAccess directory but I had no luck. Instead I had the following output: messageHTTP method GET is not supported by this URL descriptionThe specified HTTP method is not allowed for the requested resource.
My request therefore is that you assess my work to see what I am getting wrong and correct me. I am not so proficient with java web and Netbean IDE. The attached are the work I have done so far
Index.jsp Codes:
<!DOCTYPE html>
<head>
<title>Web Cam Access</title>
<script src="http://code.jquery.com/jquery-1.7.2.min.js"></script>
<script type="text/JavaScript" src="jquery. webcam.min.js"></script>
</head>
<body>
<video autoplay></video>
<form><input type='button' id='capture' value="Capture Image!"/></form>
<div id="webcam"></div>
<p><a href="javascript:webcam.capture();void(0);">
</a></p>
<script type="text/javascript">
jQuery("#webcam").webcam({
width: 320,
height: 240,
mode: "callback",
swffile: "jscam.swf",
});
</script>
<canvas id='canvas' width='150' height='170'></canvas>
<script language='javascript'>
document.getElementById('capture').onclick = function () {
var video = document.querySelector('video');
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
ctx.drawImage(video, 0, 0, 300, 250);
var data = ctx.getImageData(0, 0, canvas.width, canvas.height);
// for (n = 0; n < data.width * data.height; n++) {
// var index = n * 4;
// data.data[index + 0] = 255 - data.data[index + 0];
// data.data[index + 1] = 255 - data.data[index + 1];
// data.data[index +`` 2] = 255 - data.data[index + 2];
// }
ctx.putImageData(data, 0, 0, canvas.width, canvas.height);
/*
* HttpRequest is used to send the image to the ImageServlet
* by the following codes...
*/
var imgData = canvas.toDataURL();
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("POST", "/WebcamAccess/capture", true);
xmlhttp.send(imgData);
}
</script>
<script src="webcam.js"></script>
</body>
</html></pre>
<pre lang="xml"><u>Web.xml Code:
</u>
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
<description>Image Capture Tutorial</description>
<display-name>Tutorial</display-name>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<!--
<servlet>
<servlet-name>ImageServlet</servlet-name>
<servlet-class>controller.ImageServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>ImageServlet</servlet-name>
<url-pattern>/capture</url-pattern>
</servlet-mapping>
</web-app>
ImageServlet Code:
package controller;
import java.io.File;
import java.io.FileOutputStream;
import java.io.Reader;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import sun.misc.BASE64Decoder;
public class ImageServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response) {
try {
StringBuffer buffer = new StringBuffer();
Reader reader = request.getReader();
int current;
while ((current = reader.read()) >= 0) {
buffer.append((char) current);
}
String imgName;
imgName = "abc";
String data = new String(buffer);
data = data.substring(data.indexOf(",") + 1);
System.out.println("PNG image data on Base64: " + data);
FileOutputStream output = new FileOutputStream(new File("/C:/WebcamAccess/"
+ imgName + ".png"));
output.write(new BASE64Decoder().decodeBuffer(data));
output.flush();
output.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
modified 8-Jul-15 7:50am.
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