AJAX und das Springframework

Transcription

1 AJAX und das Springframework Peter Welkenbach Guido Schmutz Trivadis GmbH Basel Baden Bern Lausanne Zürich Düsseldorf Frankfurt/M. Freiburg i. Br. Hamburg München Stuttgart. Wien

2 Lightweight Container Architecture (1) UI Layer MVC Framework Business Interface POJO Implementation Middle Layer O/R Mapp. Framework Lightweight Container Registry Web Container J2EE Server EIS Layer Database Legacy System AJAX und das Springframework

3 The Problem Martin Fowler s Movie Sample class MovieLister... public Movie[] moviesdirectedby(string arg) { List allmovies = finder.findall(); for (Iterator it = allmovies.iterator(); it.hasnext();) { Movie movie = (Movie) it.next(); if (!movie.getdirector().equals(arg)) it.remove(); return (Movie[]) allmovies.toarray(new Movie[allMovies.size()]); public interface MovieFinder { List findall(); class MovieLister... private MovieFinder finder; public MovieLister() { finder = new ColonMovieFinder( "movies1.txt"); Dependency to be avoided AJAX und das Springframework

4 The Solution Using Inversion of Control (IoC) class MovieLister... private MovieFinder finder; public void setfinder(moviefinder finder) { this.finder = finder; class ColonMovieFinder... public void setfilename(string filename) { this.filename = filename; <beans> <bean id="movielister" class="movielister"> <property name="finder"> <ref local="moviefinder"/> </property> </bean> <bean id="moviefinder" class="colonmoviefinder"> <property name="filename"> <value>movies1.txt</value> </property> </bean> </beans> Dependency injected by assembler AJAX und das Springframework

5 Overview of Spring Components (1) Spring ORM Spring Web Spring AOP Source-level metadata AOP infrastructure Hibernate support ibatis support JDO support OJB support Spring DAO Transaction infrastructure JDBC support DAO support WebApplicationContext Multipart resolver Web utilities Spring Context ApplicationContext UI support, JNDI support EJB support, Validation Remoting, Mail Spring Web MVC Web MVC framework Web views JSP/Velocity PDF/Excel Spring Core Supporting utilities Bean factory/container AJAX und das Springframework

6 TransactionScript Architektur AJAX und das Springframework

7 TableModule Architektur AJAX und das Springframework

8 Rich Domain Model Architektur AJAX und das Springframework

9 DAO Configuration in BeanFactory Bean.xml <beans> <!-- basic DataSource impl, use PropertyPlaceholderConfigurer to set values--> <bean id="datasource" class="org.springframework.jdbc.datasource.drivermanagerdatasource"> <property name="driverclassname"><value>oracle.jdbc.oracledriver</value></property> <property <property name="username"><value>scott</value></property> <property name="password"><value>tiger</value></property> </bean> <! Use DAO: JDBC implementation --> <bean id="userdao" class="com.trivadis.lwc.ch04.dao.jdbc.userdaoimpl"> <property name="datasource"><ref local="datasource"/></property> </bean> </beans> AJAX und das Springframework

10 Spring JDBC DAO - Simple Query public class com.trivadis.lwc.ch04.dao.jdbc.userdaoimpl extends JdbcDaoSupport implements UserDao {.. /* * Returns a list of users looking something like this: * [{ name = Bob, id =1, { name = James, id =2] */ public List getuserlist() { return getjdbctemplate().queryforlist( select * from usertable );.. AJAX und das Springframework

11 Spring JDBC Object Query public class JdbcUserDAO extends JdbcDaoSupport implements UserDao {.. private class UserQuery extends MappingSqlQuery { public UserQuery (DataSource ds) { super(ds, "SELECT id, name FROM usertable WHERE id =?"); super.declareparameter(new SqlParameter("id", Types.INTEGER)); compile(); public Object maprow(resultset rs, int rownum) throws SQLException { User user = new User(); user.setid((integer)rs.getobject("id")); user.setname(rs.getstring("name")); return user; // returns a User object public User getuser(integer id) { UserQuery userquery = new UserQuery(getDataSource()); Object[] parms = new Object[1]; parms[0] = id; List users = userquery.execute(parms); return (User) users.get(0); AJAX und das Springframework

12 Sample DAO using HibernateTemplate public class com.trivadis.lwc.ch04.dao.hibernate.userdaoimpl extends HibernateDaoSupport implements UserDao {... public List getusersforname(string name) { return gethibernatetemplate().find( "from test.user user where user.name=?", name);... AJAX und das Springframework

13 Spring s transaction manager Spring s transaction managers delegate transaction- management responsibility to platform-specific transaction implementation Plattform Transaction Manager Spring s Transaction Managers DataSource Transaction Manager JDO Transaction Manager JTA Transaction Manager Hibernate Transaction Manager Persistence Broker Transaction Manager JDBC Hibernate JDO OJB JTA Platfrom-Specific Transaction Implementation AJAX und das Springframework

14 Declaring transactions To employ declarative transactions in Spring application, use TransactionProxyFactoryBean <bean id= greetingservice class="org.springf...transaction.interceptor.transactionproxyfactorybean"> <property name="transactionmanager"><ref bean="transactionmanager"/> </property> <property name="target"> <bean class= com.trivadis.lwc.ch06.greetingserviceimpl /> </property> <property name="transactionattributes"> <props> <prop key="insert*">propagation_required,-mycheckedexception</prop> <prop key="update*">propagation_required</prop> <prop key="*">propagation_required,readonly</prop> </props> </property> </bean> The transaction property descriptor takes the following form PROPAGATION_NAME,ISOLATION_NAME,readOnly,+Exception1,-Exception2 AJAX und das Springframework

15 Spring Presentation Layer - Web AJAX Integration DWR (Direct Web Remoting) provides tight integration with Java DWR provides two major functions: A dynamic Java JavaScript proxy generation library (engine.js) Utility library of miscellaneous JavaScript functionality (util.js) DWR-Servlet finds Business Services via Spring DWR generates JavaScript-Proxies for the registered Business Services DWR encapsultes the remote communication One can call the Java Business Services from within the Browser via JavaScript DWR.js JavaScript Browser Client Tier DWR-Proxies DWR-Servlet Presentation layer Business Service Application Context Business services Layer AJAX und das Springframework

16 DWR How it works The event handler (e.g. onclick() ) calls a Javascript function generated by DWR to match a server side function written in Java. DWR then handles all the remoting details, including converting all the parameters and return values between Javascript and Java. DWR then executes the supplied callback function (populatelist) in the example below which uses a DWR utility function to alter the web page. AJAX und das Springframework

17 Example Demo = Generated DWR JavaScript Service-Adapter to Java class Demo function readperson() { Demo.getExamplePerson(fillForm); call function fillform(aperson) { person = aperson; DWRUtil.setValues(person); callonload(init); Via Reflection JavaScript <INPUT id=name> <INPUT id=salary> HTML Public class Person { private String name; private float salary; Java public class Demo { public Person getexampleperson(){ return person; AJAX und das Springframework

18 Web.xml <servlet> <servlet-name>dwr-invoker</servlet-name> <servlet-class> org.directwebremoting.servlet.dwrservlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dwr-invoker</servlet-name> <url-pattern>/dwr/*</url-pattern> </servlet-mapping> <listener> <listener-class> org.springframework.web.context.contextloaderlistener <listener-class> </listener> AJAX und das Springframework

19 Web-page: <script type='text/javascript' src='dwr/engine.js'></script> <script type='text/javascript' src='dwr/util.js'></script> <script type='text/javascript'src='dwr/interface/person.js'></script> AJAX und das Springframework

20 DWR und Spring Konfiguration <dwr> <allow> <create creator= spring javascript= person scope= session > <param name= class value= com.trivadis.dwr.person /> </create> </allow> </dwr> AJAX und das Springframework

21 Die Autoren Guido Schmutz Trivadis AG Papiermühlestrasse 73 CH-3014 Bern Peter Welkenbach Trivadis GmbH Lyoner Strasse 15 D Frankfurt AJAX und das Springframework