this and super are keywords isn't it, then how can we use them for passing arguments to constructors the same way as with a method??
In short how is it that these can show such distinct behaviours??
Hello, I want to determine if a string is the name of a month and I want to do it relatively quickly. The function that is currently stuck in my brain is something like:
boolean isaMonth( String str ) {
String[] months = DateFormatSymbols.getInstance().getMonths();
String[] shortMonths = DateFormatSymbols.getInstance().getShortMonths();
int i;
for( i = 0; i<months.length(); ++i;) {
if( months[i].equals(str) ) return true;
if( shortMonths[i].equals(str ) return true;
}
return false;
}
However, I will be processing lots of text, passed one string at a time to this function, and most of the time I will be getting the worst case of going through the entire loop and returning false.
I saw another question that talked about a Regex to match a month name and a year which could be adapted for this situation. Would the Regex be faster? Is there any other solution that might be faster?
I've set up a simple Eclipse 3.5/Jetty 6.1 web app which returns hello world. It works. This is on Windows and uses the "Jetty Generic Server Adapter". I have auto deployment working so that it deploys after changes periodically.
How do I go about setting it up so that if I change any static content it doesn't have to redeploy i.e I can just hit F5 to see the changes straight away. For minor HTML changes it's quite unusable waiting 20-30 seconds for a deployment.
Ok this is a homework questions, but I cannot find the answer anywhere, not even in the book.
Path to Files
If the user wants to specify a path for a file, the typical forward slash is replaced by ________.
can you help?
I seem to have two options on how to implement arrays, and I want to know which I should go with:
Use the ARRAY data type and (from what I understand) effectively serialize data objects into the database (which in my case are just wrapped primitive types; don't know of another way to make this work).
Use a separate table and map with foreign keys for each array item.
If you have experience with this (especially with H2), which would you recommend?
I have a simple UDP server that creates a new thread for processing incoming data. While testing it by sending about 100 packets/second I notice that it's memory usage continues to increase. Is there any leak evident from my code below?
Here is the code for the server.
public class UDPServer
{
public static void main(String[] args)
{
UDPServer server = new UDPServer(15001);
server.start();
}
private int port;
public UDPServer(int port)
{
this.port = port;
}
public void start()
{
try
{
DatagramSocket ss = new DatagramSocket(this.port);
while(true)
{
byte[] data = new byte[1412];
DatagramPacket receivePacket = new DatagramPacket(data, data.length);
ss.receive(receivePacket);
new DataHandler(receivePacket.getData()).start();
}
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
Here is the code for the new thread that processes the data. For now, the run() method doesn't do anything.
public class DataHandler extends Thread
{
private byte[] data;
public DataHandler(byte[] data)
{
this.data = data;
}
@Override
public void run()
{
System.out.println("run");
}
}
Say I have the following:
Class myclass
{
public string stra ="", strb = ""
myclass(String a, String b){stra=a;strb=b}
}
//then in the app I want to do:
myclass myclassinst1 = new myclass("blah","xxxx");
myclass myclassinst2 = new myclass("blah2","yyyy");
myclass myclassinst3 = new myclass("blah3","zzzz");
list <myclass> mylist = new ArrayList<myclass>();
mylist.add(myclassinst1 );
mylist.add(myclassinst2 );
mylist.add(myclassinst3 );
//How would I then convert that to a String[] Array of all the stra elements without using a loop.
//eg:
String[] strarr_a = mylist.toarray(myclass.stra);
String[] strarr_b = mylist.toarray(myclass.strb);
//instead of having to do
String[] strarr_a = new String[mylist.size()];
String[] strarr_b = new String[mylist.size()];
for (int i=0;i<mylist.size();i++)
{
strarr_a[i] = mylist.get(i).stra;
strarr_b[i] = mylist.get(i).strb;
}
I have this code:
BufferedReader br =new BufferedReader(new FileReader("userdetails.txt"));
String str;
ArrayList<String> stringList = new ArrayList<String>();
while ((str=br.readLine())!=null){
String datavalue [] = str.split(",");
String category = datavalue[0];
String value = datavalue[1];
stringList.add(category);
stringList.add(value);
}
br.close();
it works when the variables category and value do not have a comma(,),however the values in the variable value does contain commas.Is there a way that I can split the index of the without using comma?
Can anyone help me find where the execption is? I can't seem to find the problem..
public void fieldChanged(Field f, int context){
//if the submit button is clicked
try{
stopTime = System.currentTimeMillis();
timeTaken = stopTime - startTime;
timeInSecs = ((timeTaken/1000));
speed = 45/timeInSecs;
Dialog.alert("Speed of Delivery: " + speed + "mph");
}
catch(ArithmeticException e){
Dialog.alert("error " + speed);
e.printStackTrace();
}
}
startTime variable is a global variable..
public String sizeOfSupermarket() {
String size;
switch (this.numberOfProducts) {
case (this.numberOfProducts > 5000):
size = "Large";
break;
case (this.numberOfProducts > 2000 && this.numberOfProducts < 5000):
size = "Medium";
break;
case (this.numberOfProducts < 2000):
size = "Small";
break;
}
return size;
}
the above is wrong, how to write the compare statement in case statement?
Hi
I am extracting data from an xml file converting it into json and rendering the images which i am retriving to the html file via jtemplate.now i want to user scroller and scroll the images .i can call to the scroller plugin but it is not scrolling throuhg . can any one help me please.
I have a string;
String allIn = "(50 > 100) AND (85< 100)";
Now I need to evaluate if the conditions inside are TRUE or FALSE, how can I do it?
In real the string will be a value from a field in my DB, where I will substitute different values and they will form a string as shown above.
Let's suggest that I have a bean defined in Spring:
<bean id="neatBean" class="com..." abstract="true">...</bean>
Then we have many clients, each of which have slightly different configuration for their 'neatBean'. The old way we would do it was to have a new file for each client (e.g., clientX_NeatFeature.xml) that contained a bunch of beans for this client (these are hand-edited and part of the code base):
<bean id="clientXNeatBean" parent="neatBean">
<property id="whatever" value="something"/>
</bean>
Now, I want to have a UI where we can edit and redefine a client's neatBean on the fly.
My question is: given a neatBean, and a UI that can 'override' properties of this bean, what would be a straightforward way to serialize this to an XML file as we do [manually] today?
For example, if the user set property whatever to be "17" for client Y, I'd want to generate:
<bean id="clientYNeatBean" parent="neatBean">
<property id="whatever" value="17"/>
</bean>
Note that moving this configuration to a different format (e.g., database, other-schema'd-xml) is an option, but not really an answer to the question at hand.
My problem is i have a class and in it there is a list of elements of another class.
public class Branch
{
private ArrayList<Player> players = new ArrayList<Player>();
String brName;
public Branch() {}
public void setBr(String brName){this.brName = brName;}
public String getBr(){return brName;}
public ArrayList<Player> getPlayers() { return players; }
public void setPlayers(ArrayList<Player> players) { this.players =new ArrayList<Player>(players); }
}
public class Player
{
private String name;
private String pos;
private Integer salary;
private Integer number;
public Player(String name, String pos, Integer salary, Integer number)
{
this.name = name;
this.pos = pos;
this.salary = salary;
this.number = number;
}
public Player(){}
public String getName() { return name; }
public String getPos() { return pos; }
public Integer getSalary() { return salary; }
public Integer getNumber() { return number; }
public void setName(String name) { this.name = name; }
public void setPos(String pos) { this.pos = pos; }
public void setSalary(Integer salary) { this.salary = salary; }
public void setNumber(Integer number) { this.number = number; }
}
My problem is to print the players of a Branch with their name,pos,salary,number.
For this i tried this simply :
String p1,p2;
int a1,a2;
p1 = input.readLine();
p2 = input.readLine();
a1 = Integer.parseInt(input.readLine());
a2 = Integer.parseInt(input.readLine());
players[0].setName(p1);
players[0].setPos(p2);
players[0].setSalary(a1);
players[0].setNumber(a2);
ptmp.add(players[0]);
myBranch[0].setPlayers(ptmp);
System.out.println(myBranch[0].brName + " " + myBranch[0].getPlayers());
I wrote this just to try how to display. I created an array of Players, and Branches so they already defined. The problem is getPlayers() doesn't give me any result. What is the way to do this?
I want to have a generic object that implements an interface.
I mean if i have a class A
Class A <E>{
E x;
}
I want to make sure that x will implement a particular interface(myInterface). In other words, that the type E implements an interface.
Am about to do a homework, and i need to store quite a lot of information (Dictionary) in a data structure of my choice. I heard people in my classroom saying hash-tables are the way to go. How come?
I'm trying to match the username with a regex. Please don't suggest a split.
USERNAME=geo
Here's my code:
String input = "USERNAME=geo";
Pattern pat = Pattern.compile("USERNAME=(\\w+)");
Matcher mat = pat.matcher(input);
if(mat.find()) {
System.out.println(mat.group());
}
why doesn't it find geo in the group? I noticed that if I use the .group(1), it finds the username. However the group method contains USERNAME=geo. Why?
Coming from other web frameworks, I'm used to being able to map parts of a URL to method parameters. I know that web.xml provides a way to map an entire URL to a Servlet but is there a way to get more features out of this, such as mapping pieces of the URL to method parameters?
I've come across Netbeans but is there any tools out there that lets you build things event driven ?
I'm looking for a feature like being able to drag and drop UI components, and add methods to buttons directly by double clicking it (kinda like visualbasic) and viewing the source.
Let's say I have a thread pool containing X items, and a given task employs Y of these items (where Y is much smaller than X).
I want to wait for all of the threads of a given task (Y items) to finish, not the entire thread pool.
If the thread pool's execute() method returned a reference to the employed thread I could simply join() to each of these Y threads, but it doesn't.
Does anyone know of an elegant way to accomplish this? Thanks.
Hi guys,
it may be a nooby question, but I've never needed it before:
I have several strings and I want to compare them to given ones...
At first glance it would lead to a switch/case construction in what every available entry is checked.
Is there a more elegant way to swap those strings as key/value datas?
greets,
poeschlorn
i'm having a problem loading an image from a package i created in the project that was set to contain images, i have to write the whole picture location in the computer instead of just the package that contains it. i've tried several things but nothing seams to work...
where is the command i use to load the image :
searchBar = ImageIO.read(new File("C:\\Users\\ASUS\\Documents\\NetBeansProjects\\Project\\src\\Images\\search.jpg"));
"Images" is a package in my project , this works, but when i try loading the image without the "C:\..." only with the "\Images..." it doesn't , so i have to change it every time i open this project in another computer.
hopefully one of u has the answer for me , thanks in advance for any answer :)
Hello,
I'm not able to understand the following multi-dimensional code. Could someone please clarify me?
int[][] myJaggedArr = new int [][]
{
new int[] {1,3,5,7,9},
new int[] {0,2,4,6},
new int[] {11,22}
};
May I know how it is different from the following code?
int[][] myArr = new int [][] {
{1,3,5,7,9},
{0,2,4,6},
{11,22} };
I came across this weird (in my opinion) behavior today. Take this simple Test class:
public class Test {
public static void main(String[] args) {
Test t = new Test();
t.run();
}
private void run() {
List<Object> list = new ArrayList<Object>();
list.add(new Object());
list.add(new Object());
method(list);
}
public void method(Object o) {
System.out.println("Object");
}
public void method(List<Object> o) {
System.out.println("List of Objects");
}
}
It behaves the way you expect, printing "List of Objects". But if you change the following three lines:
List<String> list = new ArrayList<String>();
list.add("");
list.add("");
you will get "Object" instead.
I tried this a few other ways and got the same result. Is this a bug or is it a normal behavior? And if it is normal, can someone explain why?
Thanks.
I have data from a database loaded into a JTable through a custom table model. I want to have a column (should be the first column) which simply shows the display row number (i.e. it is not tied to any data (or sorting) but is simply the row number on the screen starting at 1). These "column headers" should be grayed out like the row headers.
Any idea how to do this?
Thanks