??
Grails??(Grails Services)
??????????????A service is a class that holds one or more methods that implement business logic. Logical parts of the business logic are contained in seperate service classes. ??????????????????????????????????????????????????
Services need to be registered with the middle tier and also need transactional configuration next to the configuration of optional AOP services.
??????????????(application-scoped)??????????(instance variables)??????????????????
????????
????????????????????"Service"."??"???????"CountryService"?
????????????????????????????"transactional"?false????????
class CountryService {
boolean transactional = false
}????(Dependency Injection)
????????????????????????CountrySerice???????"countryService"?
CountryService countryService
??????????????????javax.sql.DataSource??
javax.sql.DataSource dataSource
???? Spring's JdbcTemplate ??
Groovy Sql ???????????? SQL ???
????
???????????????????????????????????controller??
class CountryService {
def String sayHello(String name) {
return "hello ${name}"
}
}class GreetingController {
CountryService countryService
def helloAction = {
render(countryService.sayHello(params.name))
}
}
?????????????????
http://myserver:8080/myapp/greeting/helloAction?name=Falken???????????????? "hello Falken" ???? ??controller???????
Grails controllers?
Alternatively, you can access services from other places of your web application (like servlets) if you need it. Service objects are beans which can be retrieved from the
Spring Bean Factory. You can proceed this way:
Implement a java interface containing the service method definitions which you want to be available, for example:
package serviceinterfaces;public interface CountryServiceInt {
public String sayHello(String name);
}
Save it in your "<..>/myapp/src/java/serviceinterfaces" directory
Modify the CountryService groovy class for implementing the CountryServiceInt interface:
class CountryService implements serviceinterfaces.CountryServiceInt { def String sayHello(String name) {
return "hello ${name}"
}
}
For accessing the service from a servlet you can do this:
ApplicationContext ctx = (ApplicationContext) request.getSession().getServletContext().getAttribute(GrailsApplicationAttributes.APPLICATION_CONTEXT);
CountryServiceInt service = (CountryServiceInt) ctx.getBean("countryService");
String str = service.sayHello(request.getParameter.("name"));
//do something with str
Close