InfoCenter Home > 4.2.2.3.8.1.2a: JSP .91 syntax: <REPEAT> tag results set and the associated beanThe <REPEAT> tag iterates over a results set. The results set is contained within a JavaBean. The bean can be a static bean (for example, a bean created by using the IBM WebSphere Studio database wizard) or a dynamically generated bean (for example, a bean generated by the <DBQUERY> tag). The following table is a graphic representation of the contents of a bean, myBean:
Some observations about the bean:
The following table compares using the <REPEAT> tag to iterate over static bean versus a dynamically generated bean:
Implicit and explicit indexingExamples 1, 2, and 3 show how to use the <REPEAT> tag. The examples produce the same output if all indexed properties have 300 or fewer elements. If there are more than 300 elements, Examples 1 and 2 will display all elements, while Example 3 will show only the first 300 elements. Example 1 shows implicit indexing with the default start and default end index. The bean with the smallest number of indexed properties restricts the number of times the loop will repeat. <table> <repeat> <tr><td><insert bean=serviceLocationsQuery property=city></insert></tr></td> <tr><td><insert bean=serviceLocationsQuery property=address></insert></tr></td> <tr><td><insert bean=serviceLocationsQuery property=telephone></insert></tr></td> </repeat> </table> Example 2 shows indexing, starting index, and ending index: <table> <repeat index=myIndex start=0 end=2147483647> <tr><td><insert bean=serviceLocationsQuery property=city(myIndex)></insert></tr></td> <tr><td><insert bean=serviceLocationsQuery property=address(myIndex)></insert></tr></td> <tr><td><insert bean=serviceLocationsQuery property=telephone(myIndex)></insert></tr></td> </repeat> </table> The JSP compiler for the Application Server Version 3 is designed to prevent the ArrayIndexOutofBoundsException with explicit indexing. Consequently, you do not need to place JSP variable data syntax before the <INSERT> tag to check the validity of the index. Example 3 shows explicit indexing and ending index with implicit starting index. Although the index attribute is specified, the indexed property city can still be implicitly indexed because the (myIndex) is not required. <table> <repeat index=myIndex end=299> <tr><td><insert bean=serviceLocationsQuery property=city></insert></tr></td> <tr><td><insert bean=serviceLocationsQuery property=address(myIndex)></insert></tr></td> <tr><td><insert bean=serviceLocationsQuery property=telephone(myIndex)></insert></tr></td> </repeat> </table> Nesting <REPEAT> tagsYou can nest <REPEAT> blocks. Each block is separately indexed. This capability is useful for interleaving properties on two beans, or properties that have sub-properties. In the example, two <REPEAT> blocks are nested to display the list of songs on each compact disc in the user's shopping cart. <repeat index=cdindex> <h1><insert bean=shoppingCart property=cds.title></insert></h1> <table> <repeat> <tr><td><insert bean=shoppingCart property=cds(cdindex).playlist></insert> </td></tr> </table> </repeat> </repeat>
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