JSP :: Variables / Attributes Scope Inside Tag File
Jul 3, 2014
I have an issue with variables/attributes scope inside a jsp tag file.
In short, I have a tag with an attribute named "id". If the page using my tag has a variable called "id" (maybe coming from the spring model) and I call my tag WITHOUT specifying the id attribute, inside my tag I still can acces to the "id" attribute that was defined in the page but I don't want this behavior; if the tag is called without the "id" attribute then it should defaults to empty/null.
(...)
The id is: ${id} // <- Prints 'X'
<my:print /> <- Prints 'X' ! I want it to not print anything in that case
<my:print id="Y"/> <- Prints 'Y'
(...)
What I want is to have the tag attributes live only in the tag, without having any knowledge of any variable outside of the tag itself. Is it possible?
My current workaround is to remove the "id" attribute, enable dynamic attributes and with a scriptlet search in the dynamic attributes map for the "id" and save it in a variable with a different name (e.g. "__id").
Viewing this example of pagination [URL] and other similar beans for pagination, why do they do these beans view scoped? These beans dont contain any properties for a form so they could be application scoped, right?
If I have an integer variable like int a=9 then in the switch case If i write
switch(a) { case 4+a: System.out.println("hii"); }
Then why is this statement a compile-time error that variables cannot be used inside a case statement why does the compiler not subtitutes the values in place of the variables.
So basically what problem it creates for which the language developers did not include it as a proper syntax,is there any reason behimd this because of jump table?
I am having an issue with using FileWriter to print some text to a text file. In the following code, I am supposed to be able to print the initial attributes and the user changed inputs into a file but all I am getting is the memory locations of the objects I created in one long line.
package project3final; import java.io.*; import java.util.*; public class Project3Final { static class Instrument { char [] stringNames = {'E', 'A', 'D', 'G', 'B', 'E'}; private final String instrumentName;
I have a managed bean for a form. I map the fields filled in the form with managed bean properties. when I submit the form and click new form , values from the previous form submitted gets displayed in the input fields. I used the scope of the from bean to session. what should be its scope so that values should be destroyed after I submit the form .For every new form ,new bean has to be initialized. On submit I navigate to another bean with session scope.
I'm just wondering why variables in interface can't be instance scope?
interface Test{ int a; }
And then
Test test = new TestImpl(); test.a=13;
Yes, it violates OO, but I don't see why this is not possible? Since interface is not an implementation, therefore it can;t have any instance scope variable. I can't find the correlation of interface being abstract and being able to hold instance scope variable. There's gotta be another reason. I'm just curious about any programmatic limitation, not deliberate design constraint. the example of programmatic limitation is like when Java forbids multiple inheritance since when different parents have the exact same method, then the child will have trouble determining which method to run at runtime.
Now if I am in the admin 1 environment, I would initialize my servlet with request parameter admin=1 and the servlet should load email address of admin 1 and similarly when in the environment 2, should load the servlet with admin 2.
I could do the same by putting the email address of the respective admin as request param value, but i don't want to the email address to appear in the url.
now, i want to access a managed bean's method to execute a service call related to the code embedded in the hyperlink.
My Managed bean
@ManagedBean(name="details") @SessionScoped public class XXXX extends Bean implements Serializable{ public XXXX(){...... } public myMethod(..){ service.getDataRelatedToHyperlinkCode(....passing code here to fetch details from DB) } }
if i use postConstruct annotation it is getting executed only once since it is a session scope. and point to be noted is i cannot use viewscope and requestscope.
I'm trying to access class file which is inside the package and package is inside the jar file but I can't access that class file inside my source file . All files are on desktop .
I have a source code here that counts the frequency of alphabetic characters and non-alphabetic characters (see the source code below).
import java.io.*;
public class letterfrequency { public static void main (String [] args) throws IOException { File file1 = new File ("letternumberfrequency.txt"); BufferedReader in = new BufferedReader (new FileReader (file1));
[Code] ....
But, let's just say that now I have the following characters in the text file, "letternumberfrequency.txt": 71 geese - 83 cars - 58 cows- 64 mooses- 100 ants- 69 bangles- 90 molehills - 87 noses
The numbers inside that text file would be considered as strings, am I right? But I want to extract the numbers so that I can also be able to count their frequency - not as individual digits but as whole numbers (that is how many "71", "83", "58", "64", etc. are there...). Would using "Double.parseDouble ()" work?
I need to read a csv file from the disk and manipulate the data inside. My problem is that if the csv (excel format) contains "" in any of it's values the whole string line gets saved/displayed incorrectly . For example for the line in the csv file :
I know that the simple deployment using only applet tags inside HTML causes severe security restriction for the applet on the client side. but can this simple HTML file contains .jar files inside the applet tags instead of .class files.
I have this program, I am wondering if it is possible to call files from the main method and sort them into my saveOneRocord method? If so, how would that look?
In my case my managed bean is View Scoped and it supports a UI page which has multiple forms and each form is submitted as AJAX POST request.
As per the statndard, setting restriction to 5 should create 5 views and after that based on LRU algorithm the oldest views should get deleted if 6th views is created.
Therefore any action on the oldest view will throw the ViewExpiredException and i simply redirect the user to view expired page.
1) When i set the restriction to 5 views, i open 4 tabs with 3 forms each. 2) I submit the 3 forms on first tab everything works fine. 3) As soon as I go to 2nd tab and submit the first form thr, i get view expired exception 4) It seems I am exceeding the number of views I mentioned in web.xml
I want to know :
1) Does every AJAX POST submit itself creates a view ? 2) How I can count the number of views created in a session ? 3)Can i force expiry of a view in JSF 2.0.2 while the session is still alive ? 4) Normally JSF 2.0.2 session cachces the views. Lets assume session is alive the entire day but a view was created in morning at 9:00 AM and is not used again the entire day. Assuming that session doesn't reaches the max number of views it can save in entire day, will the view created in morning expire on its own after certain interval of time ? If not , can we still force its expiry while keeping the session alive ?
I have an assignment on sorting, i kno i can get the sorting down but im having an issue with inputing the 512 ints in a file into an array. the instructor provided us with a file with 4 equal sets of ints. i tried to make my array of size [scan.nextInt()] and it cuts off the last 21 ints. and skips the first int. how can i get all of the integers in the text file into my array? this is what i have so far. if i hard code the array to size 50000 and then try to print the array it compiles but errors out when running it.
System.out.println("Please Enter text file in this format, XXXXX.txt :"); String file =fileName.nextLine(); Scanner scan = new Scanner(new File(file)); int [] data = new int[scan.nextInt()]; <-------here it skips first int int count= data.length; for (int i=0; i<data.length-1;i++) { data[i]=scan.nextInt(); } System.out.print(Arrays.toString(data));
rst 4 ints in output are: 501, 257, 390, 478...., supposed to be 492,501,390....and last ints are: ....88, 83, 79, 0 and supposed to be :88 83 79 77 76 72 71 71 66 57 56 48 48 41 33 30 23 23 18 17 15 13 9....it replace last ints with 0. why ? and how do i fix this. attached it the text file
We can have attributes in different scopes in a JSP page. Suppose there is an attribute named 'name' with values in different scopes as below:
request - A session - B application - C page - D
Suppose I print ${name} in a JSP page, then what will be the value printed on the JSP? And, what will be the preference order of attributes search in different scopes?
I am new to Java and I am doing an assignment to identify Class and Attributes from below example. How to identify 7 classes and its attributes from this scenario:
ABC Maps Maker produces electronic maps for global positioning systems. Every map needs to define the latitude and longitude of the centre of the map, together with the length and breadth of the map. A map also has a name, and a set of geographical features.
A geographical feature is something noticeable in a a map; e.g., a hill, or valley. Among the types of features are the following: trace features, track features and tract features.
All features have a name that is displayed on the map next to the feature. A trace feature has a coordinate point to indicate its location relative to the centre of the map. Broadcasting stations, mountain peaks, and transmission towers, are examples of trace features. Every trace feature has a description associated with it.
Examples of track features include roads, railways and rivers. Each track feature has a list of points that define its course, and a line pattern. The line pattern specifies the colour, and the thickness.
Like a track feature, a tract feature also has set of points, except that when drawn on the map, the last point is linked to the first point to enclose a complete region. Additionally, it has a fill pattern which incorporates essentially a colour.
Recall that there is a class, Point, in the java.awt package – this can be used to hold the co-ordinate of a point
