XQuery Web Apps. for Java Developers

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1 XQuery Web Apps for Java Developers

2 Common Java Setup Install database (SQLServer, PostgreSQL) Install app container (Tomcat, Websphere) Configure ORB (Hibernate) Configure MVC framework (Spring) Configure Authentication (Acegi) Configure presentation (JSF, JSP, Tapestry) Configure search index and engine (Lucene)

MVC framework (Spring) Configure Authentication (Acegi) Configure

3 Java Characteristics Object-oriented, uses imperative statements to change state

4 Java Code Example mylist.add(myobject); fos.write(mybytes); out.close(); panel.paint(); mythread.start();

5 Java Characteristics Object-oriented, uses imperative statements to change state

6 Java Characteristics Object-oriented, uses imperative statements to change state Uses getters and setters to access data

7 Java Code Example user.setname( Bob ); vector.getelementat(i); thing.setpath( /a/b/c ); request.getparameter ( search );

8 Java Characteristics Object-oriented, uses imperative statements to change state Uses getters and setters to access data Connects to a DB and sends a SQL string to be interpreted

9 Java Code Example connection = DriverManager.getConnection( jdbc... );... r = statement.executequery( SELECT * FROM BOOKS WHERE... );

10 Java Characteristics Object-oriented, uses imperative statements to change state Uses getters and setters to access data Connects to a DB and sends a SQL string to be interpreted Starts and commits transactions against a DB

access data Connects to a DB and sends a SQL string to

11 Java Code Example mytransaction.start(); //do a bunch of stuff mytransaction.commit();

12 Java Characteristics Object-oriented, uses imperative statements to change state Uses getters and setters to access data Connects to a DB and sends a SQL string to be interpreted Starts and commits transactions against a DB Uses threads and synchronize(d) for concurrent processing

and sends a SQL string to be interpreted Starts and commits

13 Java Code Example public synchronized void increment() { } counter++;

14 Java Characteristics Object-oriented, uses imperative statements to change state Uses getters and setters to access data Connects to a DB and sends a SQL string to be interpreted Starts and commits transactions against a DB Uses threads and synchronize(d) for concurrent processing Uses MVC for separation of concerns Almost everything is an object

interpreted Starts and commits transactions against a DB Uses threads and

15 XQuery App Strategies Framework Let MarkLogic fill the framework space Write mostly XML to HTML translations Put reusable and common code in library modules Run the app as a restricted user Let MarkLogic handle transactions Don t get too fancy

reusable and common code in library modules Run the app as a

16 XQuery Code Example <book> <isbn> </isbn> <title>inferno</title> <author>dante</author> </book> <select name="book"> <option value=" ">inferno by Dante</option> <option value=" ">republic by Plato</option> <option value=" ">gallic Wars by Caesar</option> </select>

value="123456789">inferno by Dante</option> <option

17 XQuery Code Example xquery version '1.0-ml'; let $books := fn:collection()/book let $books-dropdown := ( let $select-options := ( for $book in $books let $isbn := $book/isbn let $title := $book/title let $author := $book/author return <option value="{$isbn/text()}">{$title/text()} by {$author/text()}</option> ) return <select name="book"> {$select-options} </select> ) return $books-dropdown

$book in $books let $isbn := $book/isbn let $title := $book/title let $author := $book/author

18 XQuery Code Example xquery version '1.0-ml'; declare function local:build-option($book) { let $isbn := $book/isbn let $title := $book/title let $author := $book/author return <option value="{$isbn/text()}">{$title/text()} by {$author/text()}</option> }; let $books := fn:collection()/book let $books-dropdown := ( let $select-options := ( for $book in $books return local:build-option($book) ) return <select name="book"> {$select-options} </select> ) return $books-dropdown

$book/author return <option value="{$isbn/text()}">{$title/text()} by {$author/text()}</option> }; let $books :=

19 XQuery Code Example xquery version '1.0-ml'; declare function local:build-option($book) { let $isbn := $book/isbn let $title := $book/title let $author := $book/author return <option value="{$isbn/text()}">{$title/text()} by {$author/text()}</option> }; let $books := fn:collection()/book let $books-dropdown := ( <select name="book"> {$books/local:build-option(.)} </select> ) return $books-dropdown

$book/title let $author := $book/author return <option value="{$isbn/text()}">{$title/text()} by

20 XQuery Code Example xquery version '1.0-ml'; <select name="book"> {fn:collection()/book/<option value="{./isbn/text()}">{./title/text ()} by {./author/text()}</option>} </select> => <select name="book"> <option value=" ">inferno by Dante</option> <option value=" ">republic by Plato</option> <option value=" ">gallic Wars by Caesar</option> </select>

21 XQuery Code Example xquery version '1.0-ml'; <select name="book"> {fn:collection()/book/<option value="{./isbn/text()}">{./title/text ()} by {./author/text()/fn:upper-case(.)}</option>} </select> => <select name="book"> <option value=" ">inferno by DANTE</option> <option value=" ">republic by PLATO</option> <option value=" ">gallic Wars by CAESAR</option> </select>

22 XQuery App Strategies Code Write elegant expressions Use composed expressions (use few types) Embrace the step Write utility or helper functions instead of business logic Use recursion (consider xslt)

23 Code Examples Person[] persons = {alice, bob, greg}; StringBuffer sb = new StringBuffer( Hello ); for (int i=0; i<persons.length; i++) { sb.append(,, persons[i].getname()) } => Hello, Alice, Bob, Greg xquery version '1.0-ml'; declare function local:add-name($greeting, $persons) { let $person := $persons[1] let $new-greeting := fn:concat($greeting, ", ", $person/name/text ()) return if ($persons[2]) then (local:add-name($new-greeting, $persons[2 to fn:last()])) else ($new-greeting) }; local:add-name("hello", fn:collection()/person)

24 Code Examples xquery version '1.0-ml'; fn:concat("hello, ", fn:string-join(fn:collection()/person/name/text (), ", ")) => Hello, Alice, Bob, Greg

25 XQuery App Strategies Strive for elegance If you are writing a lot of code, you are probably thinking about it in the wrong way

26 Questions

Java EE Web Development Course Program

Java EE Web Development Course Program Part I Introduction to Programming 1. Introduction to programming. Compilers, interpreters, virtual machines. Primitive types, variables, basic operators, expressions,