I have a simple class, called InputManager, which has methods that communicate with another class DatabaseManager which has access to Database which is actually object that contains information about actual database.
My JFrame has Navigation class (extends JPanel). There I put all needed JButtons, JLists and so on.. This class has instance of InputManager and when user interacts with GUI components inside of it, Navigation calls InputManager methods, it then analyses the call and calls needed methods on DeviceManager, which then sends queries to Database and etc.
The problem is, that at the beginning (when user runs a program), I want to get information (which is actually values for my GUI components ) from Database. It could, for example, create another DatabaseManager and connect to the Database to get information, but it is okay to have two objects?
I was also thinking about sending same DatabaseManager object through InputManager to Navigation, but it seems strange for me to have two objects, which can interact with each other in both directions(Class A has instance of Class B, and Class B has instance of Class A). Is there anything bad this can do?
Also what I noticed that it seems odd that GUI class would have to get information from database. (Logic in GUI class).
I have a button in which I need to do the following:
After I click it It reads the values given in a jtextfield1 and in the other jtextfields I need it to settext in them from the database I mean if I have for example id=1 when I click the button it goes to the database and find the id 1 then write the infos in the other textfields
So I have an Enum file with 119 constants and each constant of that type has 20 fields that come with it. All the fields are the same type and named the same (e.g. there are 119 of Object obj, one for each constant), and I want to run the same methods over them. Since the Objects of the same type are named the same for each constant, I just have them named explicitly in get-er methods.
This worked fine when I just put all 20 fields through the constructor and set them as fields under all the constants. But I realized that if I wanted to make an instance of this Enum class, I'd have to enter in all 20 fields when they are all a set of Objects with unique values. So I then put them as fields under their own respective constant to make it easier to create instances of this enum. But now my methods don't work.
A) I don't really understand why they don't work anymore? B) Is there a way to fix it without putting all the methods under each constant?
Example:
public enum MyEnum { AAA { private MyObject obj = new MyObject (3.0); }, BBB { private MyObject obj = new MyObject (1.5); }, CCC { private MyObject obj = new MyObject (6.5); }, DDD { private MyObject obj = new MyObject (3.5); };
public double getObjVal() { return obj.value(); // it can't find this obj should I move it up to where the constants are declared? } }
Many times I have read that JSF stores de view state in session and one of the things that are stored are the values of the form fields, right? But these input field values are not stored in session, I mean, they depend of the scope of the managed bean attached to the view. If I have a view and its attached to a view scoped bean with properties for the form fields, the values will dissapear if I go to other view because the bean is view scoped so I cant say the values of the form are stored in session, right?
This program is basically complete. It compiles and runs. It is a college course assignment that I pretty much completed but for the last part in which I'm suppose to change the values of all fields and display the modified values using a toString method. Modifying the values of the fields is where I am stuck. I don't think I need to create a new text data file to do this. The instructor only asked that all the values of fields be changed and this was the last part of the assignment so I don't think it involves creating additional ObjectOutputStream and ObjectInputStream objects. I'm getting a NullPointerException error on line 161.Here is the code. I'm also including the input data file.
//create program so that objects of class can be serialized, implements interface Serialiable //create constructor with 4 parameters with accompanying get and set methods, Override toString method //create text file with 5 records, create Scanner object,ObjectOutputStream, and ObjectInputStream //create new ItemRecord object, change values of all fields in ItemRecord object using object's set methods //modify ItemRecord object using toString method
[hightlight =Java]import java.io.Serializable; public class ItemRecord implements Serializable
----jGRASP wedge2: exit code for process is 1. ----jGRASP: operation complete.
Here is the data file: A100 99.99 10 Canon PowerShot-135 A200 149.99 50 Panasonic-Lumix T55 A300 349.99 20 Nikon- D3200 DSRL A400 280.99 30 Sony- DSC-W800 A500 97.99 20 Samsung- WB35F
Here is the data file for the modified field values. B100 98.00 10 ABC1010 B200 97.00 15 DEF1020 B300 96.00 10 GHI1030 B400 95.00 05 JKL1040 B500 94.00 01 MNO1050
I have two programs that I'll post below, one is a Server and the other is a Client. The ChatServer runs once and many clients can run ChatClient from separate computers and talk together in their GUI's. The the client program comes with two buttons, one that's simulates the sending of a message to a single user ; "Send Message To User", and one that just generally sends a message ; "Send Message To All". Although now the Clients on the server seem to be able to selectively send messages to an individual by giving the recipient name, all the clients can see that message, which is not exact what I am aiming for. What I am going for is having the "Send Message To User" button click to send a message to the named user without all other users seeing the message.
Now I have tried thing like having various input output streams and trying to connect those, but no luck. Tried fiddling with having the names arraylist directing the messages to one client versus all but that did not work out either. How I what I would need to do to go about doing this?
how to differ between fields that are not exists to fields that are null? because in my api when someone wants to delete a field he sends null instead of a value. and if he doesnt want to effect this feild he doesnt send it.
I have a server with a handful of php services. I communicate with these services by creating connections from java code. The services currently respond with XML, but that can be changed if an alternative way can improve performance.
One of the things I need to do is send varying sized payload (some large) to one of the services. My current plan is to create an xml file in java and perform a POST request with the XML as the payload. I am using an XML because the data is very structured.
From a performance point of view, would it be better to send the XML as a file or just as text? Also, is there a better way to send this data? These services will eventually be used by an android app, where performance and minimizing the size of the data packages will be extremely important.
I did this using ArrayList<String> and my tests worked. Meaning I was able to read the strings in a different class through my constructor. However I want to use a string array because it will be easier to handle when I finish the program. I will send each players poker hand in and figure out who is the winner instead of putting it all onto a ArrayList and having to iterate through it. However whenever I did my check I am just printing null.
PokerFile class
void separateHands(String cards) { //ArrayList<String>playerOne = new ArrayList<String>(); //ArrayList<String>playerTwo = new ArrayList<String>(); String[] playerOne = new String[10]; String[] playerTwo = new String[10];
[Code] .....
ignore the boolean methods I was just building the structure of the program. The print file is what is outputting this:
null null null null null null
public class WinningHand extends PokerFile { //ArrayList<String> p1 = new ArrayList<String>(); //ArrayList<String> p2 = new ArrayList<String>(); String[] p1 = new String[6]; String[] p2 = new String[6]; WinningHand(String[] p1,String[] p2)
New to SMSLib. I checked some samples and docs but did not get any ref/poc wherein I can send SMS with following set-up.
1. I want to send SMS from PC which is connected to internet in office network, where I am using proxy settings to connect to internet.(Basically office PC used in LAN environment)
2. I am not sure how to set the Modem settings in this scenario.
3. What i want - want to test SMS functionality in office environment and would like to send SMS to android based mobile using SMSLib library.
4. I have done SMSLib set-up on my PC and have all the required jars/dlls placed at proper location. So no issues related with set-up. Set-up is on windows platform.
5. I have written sample POC by referring some blogs/SMSLib docs. But as mentioned in points 1 and 2 above, am not getting how to write the code.
I am trying send email .So I have downloaded javaEE and javamail jar files and added buildpath.And wrote this code below .But I am getting this exception.
I am new to java (been Reading for 2 days now), and have almost no knowledge on programming (I am a Mechanical Engineer).The problem I have is that I have to upload 5,000 files to a web page (each one is name B001400XXXX.pdf in consecutive order).I have managed to access the web page and select a few form elements using watij, but I am having a hard time sending my pdf file to the server. This is what I have so far:
Java Code: import org.watij.webspec.dsl.WebSpec; public class NewClass { public static void main(String[] args) {
I need to send a byte array across a network. I know how to do this. (server->client)
byte[] myArray = new byte[]{0,1,2,3,4,5,6,7,8,9}; DataOutputStream.write(myArray);
... and I know how to receive it.
byte[] myArray = new byte[10]; DataInputStream.read(myArray);
When I send over one of these arrays, it ends up stopping storing values in the array when only about half the array is received, even though the array is sent from the server all at once. This results in the receiver's array, in this case, being something like {1,2,3,4,0,0,0,0,0,0}.
I can easily solve this - and already have - by simply adding a loop onto it and waiting for the bytes to all be received, as the method returns the amount of bytes actually read.
I am simply wondering if there is a better solution to this, as the current solution isn't that elegant. Did I do something wrong to cause only a part of the array to be sent first? Would it be better to use DataInputStream.readByte() to read off the bytes one by one rather than an array at once, and then store them in an array afterward? Would this cause a performance decrease as each byte is read individually? (I'm sending an array of several million bytes)
Say I was to make a computer game, the first person to play the game would have a joinable game and would then be the server, and anyone joining in would be the client and the server was updated with JSON data of the clients computer game, and the server would then update each client of each characters new data using JSON, I would need fast multi threaded connection handling with minimum overhead, Is there a specific way to do this? or are there many?
I have realized there are a few ways to send and receive data using UDP and while experimenting I have also found its quite hard to synchronise.
Do I have a connection listening until there is data to be sent and then switched back to listening?
Do I have the server listening for a microsecond and then checking to see of there's anything to send for a microsecond continuously?
Do I have multiple connections for sending and receiving
Do I create new connections for each new and individual packets to be sent and received dynamically on a thread?
What is the optimum most effective way and do my examples reflect much understanding at all? my resent attempts create new problems and rather than re invent the wheel I would like to know what is normally done.
i am having a below piece of code in my worker thread. In my output i am getting xml records from the database. I'm sending this output to a input stream & finally to a sax parser.My query is, before sending to the parser i need to store the input stream in buffer. The buffer should store 1000 records. For every 1000 records the parser should be called from buffer.
while (orset.next()) { output = orset.getString("xmlrecord"); writeCount++; InputStream in = new ByteArrayInputStream(output.getBytes("UTF-8")); InputStream inputStream = new ByteArrayInputStream(output.getBytes("UTF-8")); Reader reader = new InputStreamReader(inputStream,"UTF-8");
I've just recently started playing around with network programming in Java, and I've come up with a simplistic server than can handle multiple clients and return the IP and port each one is connected to (or I'm under the impression that is so). What I've been requested to do as an exercise by one of the programming teachers at my high school (I'm not in a class, this is my own time) is send a message from one client to the other through the ServerSocket so that it may "watch" everything going on. I'm not sure how to go about this at all.
EDIT : now it never seems to go the the else or else if statements...
That is now the main problem. It never, ever, goes past the first if statement, no matter what it is.
EDIT : Okay, I haven't changed a line of code but suddenly not a single if statement is working. They just stopped. The client simply hangs and I can't type anything.
Server
public class Server implements Runnable { Socket clientSocket; Server(Socket clientSocket) { this.clientSocket = clientSocket; } public static void main(String args[]) throws Exception { ServerSocket ssock = new ServerSocket(3480); System.out.println("Listening on port 3480");
<% request.setAttribute("from", new String("test"));%>
And the I try to send the "from" value to my controller like this:
<p><a href="UserController?action=listNoDeletedFilterdUsers&from=<c:out value="${request.getAttribute('from')}"/>"> Eliminar usuarios por rango de fechas</a></p>
When I press the link and chech the HTML generated it looks like this:
I am creating a server that stores application updates. When the client connects the server send the update. The server is sending the file but the file is not complete, i.e, if the file is 317kb,its send 117kb. Below is the code I am using :
import java.io.BufferedInputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.OutputStream; import java.net.ServerSocket; import java.net.Socket; public class TestFileServer {
At first, oracle change this site a lot. I logged into this site after a long time and I was amazed to see the new changes. Moving onto the the question.
I am developing a spring mvc web application. The problem is when I send email, let say to more than 4 person, the program hangs for a while. Some friend told me to use thread pool to solve this. What is the general practice for handling this kind of situation?
This is the link [URL] and it says One significant difference between classes and interfaces is that classes can have fields whereas interfaces cannot.How can this be possible?
At the end of my main method, I want it to print out the input given that should have been stored in my sandwich class fields, but it didn't.
import java.util.*; import java.lang.*; public class SandwichBuilder { public static void main(String[] args) { Scanner inputDevice = new Scanner(System.in);
I am unsure of something. In the following class, which is read first; the static field or the main method?
class Test{ static int a = 3; public static void main(String args []) { //some code} }
I put some code in Eclipse and have tried to look at the hierarchy. It would point to all static fields being initialized in order from top to bottom, including the main method.I had thought that the main method was always the first thing in a public class to be initialized, regardless of where in the code it resides. Am I reading the Eclipse hierarchy wrong? I find Eclipse very difficult, especially since I typically code in Textmate. I just want to see how my code is operated upon,
