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Responsive Complex Interfaces in Java Generate Code-128 in Java Responsive Complex Interfaces

Responsive Complex Interfaces generate, create code128b none for java projects GS1 DataBar Overview In this chapter, jdk barcode 128 we will create user interfaces that demonstrate some advanced features of GWT. The tasks that we will address are: Pageable tables Editable tree nodes Log spy Sticky notes Jigsaw puzzle. Pageable Tables We are going to s jsp barcode code 128 tart exploring more complex GWT user interfaces in this chapter. We routinely come across some cases in today"s business world where we need to use tables to display a large amount of data. Displaying all of the available data in a table at once is not a viable option, either from the point of view of usability or from a practical perspective.

We can also potentially lock up the browser that is displaying the table, if the dataset retrieved is of a large enough size. A much better way to display this data to users would be to show them a fixed number of results first, and then provide them with the mechanism to navigate through the results; so that they can page back and forward through the data at their leisure. This makes for a nicer user experience, and also loads the smaller dataset much faster.

. Responsive Complex Interfaces In this section, jvm ANSI/AIM Code 128 we are going to create an application that provides this functionality. As a part of this sample, we are also going to learn how to use an embedded database with a GWT application..

Time for Action Interfacing a Dataset We will create an code-128c for Java application that will let us retrieve data in chunks or pages, instead of getting everything at once. We will do this by retrieving the first ten items as a result of a query, and provide a way for the user to either go forward or backward through this set of results. The steps are as follows: 1.

Create a new Java file named PageableDataService.java in the com.packtpub.

gwtbook.samples.client package.

Define the PageableDataService interface with one method to retrieve the customer data, by providing a start index and the number of items to retrieve as parameters:. public interface PageableDataService extends RemoteService { public List getCustomerData(int startIndex, int numItems ); }. 2. Create the asy jdk Code128 nchronous version of this service definition interface in a new Java file named PageableDataServiceAsync.java in the com.

packtpub. gwtbook.samples.

client package:. public interface PageableDataServiceAsync { public void getCustomerData(int startIndex, int numItems, AsyncCallback callback); }. 3. Create the imp barcode 128 for Java lementation of our pageable data service in a new Java file named PageableDataServiceImpl.java in the com.

packtpub.gwtbook. samples.

server package. Create a private ArrayList object named customerData that will be the container for the customer data:. private ArrayList customerData = new ArrayList();. 4. It will be sim code128b for Java pler if we use a database for storing our data instead of managing data structures in our service. We are going to use HSQLDB a small embedded database for storing the data that we will be accessing in this service.

First, load the data from the pre-populated database into a list:. [ 98 ]. 5 private void l jdk USS Code 128 oadData() { Class.forName("org.hsqldb.

jdbcDriver"); Connection conn = DriverManager.getConnection ( "jdbc:hsqldb:file:samplesdb", "sa", ""); Statement st = conn.createStatement(); ResultSet rs = st.

executeQuery("SELECT * FROM users"); for (; rs.next();) { ArrayList customer = new ArrayList(); customer.add((String) rs.

getObject(2)); customer.add((String) rs.getObject(3)); customer.

add((String) rs.getObject(4)); customer.add((String) rs.

getObject(5)); customer.add((String) rs.getObject(6)); customerData.

add(customer); } st.execute("SHUTDOWN"); conn.close(); }.

5. We call the lo adData() function in the constructor for the service, so that all the required data is loaded and is available after the service is initialized:. public PageableDa Code-128 for Java taServiceImpl() { super(); loadData(); }. 6. Now add the se rvice-implementation method that will send back only the requested subset of the data:. public ArrayList j2ee Code128 getCustomerData(int startIndex, int numItems) { ArrayList customers = new ArrayList(); for (int i = startIndex - 1; i < (startIndex + numItems); i++) { customers.add((ArrayList) customerData.get(i)); } return customers; }.

[ 99 ].
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