動態默認屬性grails

Question

我試圖設置一個域級的默認值。我試過但不工作

class myDomainClass{ 
    int idUser = (${session.user.id}!= null)?${session.user.id}:0; 
} 

我該怎麼辦？

Answer 1

它不起作用的原因可能是因爲session（HTTP會話）僅在控制器和GSP中可用，而不是域類。取而代之的是，獲取當前用戶的服務，並注入域類

class UserService() { 

    int currentUserId() { 
    GrailsWebRequest webRequest = WebUtils.retrieveGrailsWebRequest() 
    def session = webRequest.session 
    session.user?.id 
    } 
} 

class myDomainClass {  
    static transients = ['userService'] 

    UserService userService 
    int idUser = userService.currentUserId ?: 0 
} 

此實現訪問來自服務，不推薦使用會話這一點，但它應該工作。當然，你可以只使用相同的方法從域類訪問會話，但是這是比上面

class myDomainClass{ 
    int idUser = {-> 
     GrailsWebRequest webRequest = WebUtils.retrieveGrailsWebRequest() 
     def session = webRequest.session 
     session.user?.id ?: 0  
    }() 
} 

Answer 2

|Running Grails application 
Error | 
2013-12-18 15:50:17,476 [localhost-startStop-1] ERROR context.GrailsContextLoader - Error initializing the application: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.InstantiationException: could not instantiate test objectsmat.AnalisiIZS 
Message: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.InstantiationException: could not instantiate test objectsmat.AnalisiIZS 
    Line | Method 
->> 262 | run  in java.util.concurrent.FutureTask 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 744 | run  in java.lang.Thread 
Caused by BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.InstantiationException: could not instantiate test objectsmat.AnalisiIZS 
->> 262 | run  in java.util.concurrent.FutureTask 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 744 | run  in java.lang.Thread 
Caused by BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.InstantiationException: could not instantiate test objectsmat.AnalisiIZS 
->> 262 | run  in java.util.concurrent.FutureTask 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 744 | run  in java.lang.Thread 
Caused by InstantiationException: could not instantiate test objectsmat.AnalisiIZS 
->> 262 | run  in java.util.concurrent.FutureTask 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 744 | run  in java.lang.Thread 
Caused by InvocationTargetException: null 
->> 262 | run  in java.util.concurrent.FutureTask 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 744 | run  in java.lang.Thread 
Caused by NullPointerException: null 
->> 19 | <init> in smat.AnalisiIZS 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 262 | run  in java.util.concurrent.FutureTask 
| 1145 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 615 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 744 | run . . . in java.lang.Thread 
Error | 
Forked Grails VM exited with error 

Answer 3

類AnalisiIZS {

Campione campione; 
Date dataAnalisiCampione; 
String specieIsolata1; 
String codiceIsolato1; 
String specieIsolata2; 
String codiceIsolato2; 
String specieIsolata3; 
String codiceIsolato3; 
String specieIsolata4; 
String codiceIsolato4; 
String nomeUser; 

static constraints = { 

    dataAnalisiCampione(blank:true) 
    specieIsolata1(blank:true) 
    codiceIsolato1(blank:true) 
    specieIsolata2(blank:true) 
    codiceIsolato2(blank:true) 
    specieIsolata3(blank:true) 
    codiceIsolato3(blank:true) 
    specieIsolata4(blank:true) 
    codiceIsolato4(blank:true) 
    campione(blank:true) 
    nomeUser(display:false) 

} 

String toString(){ 
    return dataAnalisiCampione; 
}