I've a typical scenario & need to understand best possible way to handle this, so here it goes -
I'm developing a solution that will retrieve data from a remote SOAP based web service & will then push this data to an Oracle database on network.
Also, this will be a scheduled task that will execute every 15 minutes.
I've event queues on remote service that contains the INSERT/UPDATE/DELETE operations that have been done since last retrieval, & once I retrieve the events for last 15 minutes, it again add events for next retrieval.
Now, its just pushing data to Oracle so all my interactions are INSERT & UPDATE statements.
There are around 60 tables on Oracle with some of them having 100+ columns. Moreover, for every 15 minutes cycle there would be around 60-70 Inserts, 100+ Updates & 10-20 Deletes.
This will be an executable jar file that will terminate after operation & will again start on next 15 minutes cycle.
So, I need to understand how should I handle WRITE operations (best practices) to improve performance for this application as whole ?
Current Test Code (on every cycle) -
Connects to remote service to get events.
Creates a connection with DB (single connection object).
Identifies the type of operation (INSERT/UPDATE/DELETE) & table on which it is done.
After above, calls the respective method based on type of operation & table.
Uses Preparedstatement with positional parameters, & retrieves each column value from remote service & assigns that to statement parameters.
Commits the statement & returns to get event class to process next event.
Above is repeated till all the retrieved events are processed after which program closes & then starts on next cycle & everything repeats again.
Thanks for help !
I'm maintaining this Swing app that has a "print" option. Users need to be kept from interacting in any way with the underlying file system, but the print dialog offers "print to file" as one printer, and that of course allows selecting a directory and file from the file system.
Is there a painless way to override/modify the print dialog to hide the "to file" printer from this dialog? I understand the API will let me do this piecemeal but I'd rather not have to re-create most of the dialog GUI and functionality to do this.
Is a variable inside the main, a public variable?
public static void main(String[] args) {
.........
for(int i=0;i<threads.length;i++)
try {
threads[i].join();
} catch (InterruptedException e) {
e.printStackTrace();
}
long time=0;
....
}
i and time are they both public variables?
Of course if my reasoning is correct, also any variable belonging to a public method should be considered public.. am i right?
Thanks
Hi I am creating a method that will take a number and print it along with its binary representation. The problems is that my method prints all 0's for any positive number, and all 1's for any negative number
private static void display( int number ){
System.out.print(number + "\t");
int mask = 1 << 31;
for(int i=1; i<=32; i++) {
if( (mask & number) != 0 )
System.out.print(1);
else
System.out.print(0);
if( (i % 4) == 0 )
System.out.print(" ");
}
}
I use setLayout (null) and I'm trying to place the buttons and textfield places I know by x, y
The problem when I run the program no matter what software (Eclipse, bluej)
I need to run on the panel with the mouse until I stand on the position of the button and I can see it.
When I find the textfield, it is small and only when I start writing it became the size I set it
Does anyone know how to solve it?
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.
I'm using SAX and XML reader to read XML weather info from the web and it works fine if the page exists. But if for instance the user inputs an invalid city, zip etc the XML page that gets read from is empty and the app force closes with nullpointerexception. The area that generates the error is here right at open inputstream. Any suggestions?:
SAXParserFactory spf = SAXParserFactory.newInstance();
SAXParser sp = null;
try {
sp = spf.newSAXParser();
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
/* Get the XMLReader of the SAXParser we created. */
XMLReader xr = null;
try {
xr = sp.getXMLReader();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
/* Create a new ContentHandler and apply it to the XML-Reader*/
WeatherHandler myExampleHandler = new WeatherHandler();
xr.setContentHandler(myExampleHandler);
/* Parse the xml-data from our URL. */
try {
xr.parse(new InputSource(url.openStream()));
parsedWeatherDataSet =
myExampleHandler.getParsedData();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return parsedWeatherDataSet.toString();
I saw a lot of post on StackOverflow relating to this, but unable to solve my problem.
I want to open a new Panel by clicking a button.
Here is how i try to do it
parameterButton = new JButton("Parametres");
parameterButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
createParameterPanel = new DisplayParameterPanel();
createParameterPanel.setVisible(true);
add(createParameterPanel);
};
});
add(parameterButton);
When I click the parameterButton it doesn't open.
How can I open a new panel.
Thanks,
I've been working on this for one hour, just can't get it.
I have a Vector2d class:
public class Vector2d
{
public double x = 0.0;
public double y = 0.0;
....
}
This vector class has a rotate() method which is causing me trouble.
The first snippet seems to make the x and y values smaller and smaller. The second one works just fine! Am I missing something simple here?
public void rotate(double n)
{
this.x = (this.x * Math.cos(n)) - (this.y * Math.sin(n));
this.y = (this.x * Math.sin(n)) + (this.y * Math.cos(n));
}
This works:
public void rotate(double n)
{
rx = (this.x * Math.cos(n)) - (this.y * Math.sin(n));
ry = (this.x * Math.sin(n)) + (this.y * Math.cos(n));
x = rx;
y = ry;
}
I just can't spot any difference there
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} };
Write a recursive method that converts a decimal number into a binary number as a string. The method header is as follows:
public static String convertDecimalToBinary(int value)
i want to list files starting with a name like "Report" from a folder.
i found this in google to list all files but i don't how to list file starting with a name.
Thank you
File directory = new File("C:\\Users\\kiki\\Downloads");
File[] files = directory.listFiles();
for (int index = 0; index < files.length; index++)
{
//Print out the name of files in the directory
System.out.println(files[index].toString());
}
I'm trying to make like a skype-instant messager, my idea for it is to have
one server which handles multiple connections for the clients. What I now have is a friend list etc, but now I want to create Threads both for server and client to handle a conversation. The problem is that I need multiple connections between a server and one client for every conversation(I think). but i dont think it's possible. Does someone have another way for doing this or maybe a way to make multiple connections between the server and a client?
Thanks for helping me out
PS: English is not my main language so please excuse me for my grammar.
Hi, I have a string like this String str = "la$le\$li$lo".
I want to split it to get the following output "la","le\$li","lo". The \$ is a $ escaped so it should be left in the output.
But when I do str.split("[^\\\\]\\$") y get "l","le\$l","lo".
From what I get my regex is matching a$ and i$ and removing then. Any idea of how to get my characters back?
Thanks
Using
double variable = inputFile.nextDouble();
Gives the mismatch error and I can't figure out why... Anyone know what's up?
The input file is just a bunch of doubles like 5.0...
Okay here is the code snippet
String fileName;
Scanner scanner = new Scanner(System.in);
System.out.println("\nEnter file name that contains the matrix and vector: ");
fileName = scanner.nextLine();
Scanner inputFile = new Scanner(fileName);
double a1 = inputFile.nextDouble();
the input file is a plain text document .txt in this format
5.0 4.0 -3.0
4.0 2.0 5.0
6.0 5.0 -2.0
-13.0 4.0 12.0
I don't understand why it wouldn't take those as doubles...
As far as what its expecting the format of the file to be... I suppose binary? isn't that the default? I didn't specify in the code...
I have two button one textset on JFrame ,i need user used first button to browse
in your computer and other button to attche documents or image
and displayed in textset
I got this thing i'm trying to solve:
I got a ListView created using Wicket ( 1.5 ) with a lot of elements and a scroll. When new items are available, the user is asked if he would like to refresh the list via a message backed by an AjaxLink:
public void onClick(AjaxRequestTarget ajaxTarget) {
/* do something ... */
ajaxTarget.addComponent(_list);
}
So on click the list gets reloaded and the scroll position is reset to zero. Is there any way i can call JavaScript before the list reloads the save the scroll position?
(I know how to get/save the scroll position ( .scrollTop() ) , i just don't know how to call a function right before AJAX ).
hi!!I have an issue and i want your help!I have a specific REGEX which i have named it "unique" and i want to store the data that it gives me!! The prefix and the suffix of this regex!!so!!someone has told me to use
var prefix and
var suffix
but i don't know how to do it!
for your convinience i give u my xml for this regex
<reg name="unique">
<start><![CDATA[ <!-- 72 HOURS FORECASTS -->
]]></start>
<end><![CDATA[<!-- 72 HOURS FORECASTS -->]]></end>
</reg>
the code where i call this regex is
int k = 0;
for(Xml reg_is:fetchsite.child("site").child("regexps").children("reg")) {
if(reg_is.string("name").contains("unique")){
if(reg_is.child("start").content()=="")
error += "\tNo prefix reg.exp. given.\n";
else
prefix = HtmlMethods.removeBreaks(replaceVariables(reg_is.child("start").content()));
if(reg_is.child("end").content()=="")
error += "\tNo suffix reg.exp. given.\n";
else
suffix = HtmlMethods.removeBreaks(replaceVariables(reg_is.child("end").content()));
}
else{
poleis[k][0]= HtmlMethods.removeBreaks(reg_is.string("name"));
poleis[k][1] = HtmlMethods.removeBreaks(replaceVariables(reg_is.child("start").content()));
poleis[k][2] = HtmlMethods.removeBreaks(replaceVariables(reg_is.child("end").content()));
k++;
}
Hello there,
I am try to find out how to enforce uniqueness in fields other than the unique id.
Example:
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class User implements IsSerializable {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Long id;
@Persistent
private String name;
@Persistent
private String email; // <= I want this to be unique as well
}
In the example above, how can I enforce uniqueness of the email value across the database?
Daniel
Hi.
I am writing a project on Google App Engine, within it I have a number of abstract classes that I hope I will be able to use in my future projects, and a number of concrete classes inheriting from them.
Among other abstract classes I have an abstract servlet that does user management, and I hava an abstract user. The AbstractUser has all the necessary fields and methods for storing it in the datastore and telling whether the user is registered with my service or not. It does not implement any project specific functionality. The abstract servlet that manages users, refers only to the methods declared in the AbstractUser class, which allows it to generate links for logging in, logging out and registering (for unregistered users).
In order to implement the project-specific user functionality I need to subclass the Abstract user. The servlets I use in my project are all indirect descendants from that abstract user management servlet, and the user is a protected field in it, so the descendant servlets can use it as their own field. However, whenever i want to access any project specific method of the concrete user, i need to cast it to that type.
i.e.
(abstract user managing servlet)
...
AbstractUser user = getUser();
...
abstract protected AbstractUser getUser();
(project-specific abstract servlet)
@Override
protected AbstractUser getUser() {
return MyUserFactory.getUser();
}
any other project specific servlet:
int a = ((ConcreteUser) user).getA();
Well, what i'd like to do is to somehow make the type of “user” in the superclass depend on something in the project-specific abstract class. Is it at all possible?
And i don't want to move all the user-management stuff into a project-specific layer, for i would like to have it for my future projects already written :)
Thank you for your help.
Hi,
I have traced an issue with an application I am developing, it is giving me a type cast exception. Funny thing is it is saying it cannot cast "entities.Movie cannot be cast to entities.Movie"?! movies is an ArrayList.
try {
movies = getMovies();
} catch (Exception e) {
e.printStackTrace(System.out);
} finally {
try {
for (Movie movie : movies) {
output.append(" <tr>\n");
output.append(" <td>" + movie.getId() + "</td>");
output.append(" </tr>\n");
}
} catch (Exception e) {
e.printStackTrace(System.out);
}
}
Hi Folks,
I want to pass the String value between the classes both are same package. so i created the the classs like the code:
public class Map_Delegate {
String myLatitude;
String myLongitude;
String myName;
private String TAG = "Map_Delegate";
public String getMyName() {
return this.myName;
}
public void setMyName(String value) {
Log.v(TAG, value);
this.myName = value;
}
public String getMyLatitude() {
return this.myLatitude;
}
public void setMyLatitude(String value) {
Log.v(TAG, value);
this.myLatitude = value;
}
public String getMyLongitude() {
return this.myLongitude;
}
public void setMyLongitude(String value) {
Log.v(TAG, value);
this.myLongitude = value;
}
}
But it can't pass the value. I done like this code to set the value:
Map_Delegate map = new Map_Delegate();
map.setMyName(first_name_temp + " " + last_name_temp);
map.setMyLatitude(homeLatitude_temp);
map.setMyLongitude(homeLongitude_temp);
code to get the value:
Map_Delegate map = new Map_Delegate();
name_val = getMyName();
lat_val = getMyLatitude();
long_val = getMyLongitude();
Why get the Null value can you Guess? All classes in the same package and public .AnyIdea?
Hi again,
I have the following tag included in my HTML which causes the JEditorPane not to show the HTML output.
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
Not so much a big deal but anyone know why this would happen?
Cannot find too much documentation on this - best I came up with was someone having a go a few years ago to see what was supported on retro virus site.
At the minute I'm doing a simple find replace on the string which is not good - are there any better ways? I've seen a lot of people saying that RegEx is no good.
The code I have used is
this._html = this._html.replace( "<META http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">", "");
Andez
Is there a difference between these ?
if(myString.equals("")){
}
if(myString.equals(null)){
}
if(myString == ""){
}
I have a string, I don't know is it empty or has some emtpy spaces I just wan't to stop it to be written in database if it is invalid(if empty or with some blank spaces).