Grails IndexOutOfBoundsException

Question

我在 Grails 中有以下代码：

public LibraryItem createLibraryItemWithValues(ProjectItem projectItem) {
    def libraryitem = new LibraryItem ()
    libraryitem.name = projectItem.name
    libraryitem.itemtype = projectItem.itemtype.itemtype
    libraryitem.description = projectItem.description
    List<LibraryCategoryValue> libCatValues = new ArrayList<LibraryCategoryValue>();
    for (def pcv : projectItem.categoryvalues) {
        libCatValues.add(pcv.librarycategoryvalue);
    }
    if (libraryitem.id != null && !libraryitem.isAttached()) {
        libraryitem.attach()
    }
    libCatValues.each{
        it.addToLibraryitems(libraryitem)
    }
    return libraryitem.save()
}

类 LibraryCategoryValue

package ch.fhnw.accelerom.project.library

import ch.fhnw.accelerom.project.ItemType
import ch.fhnw.accelerom.project.TranslatableObject


class LibraryCategoryValue extends TranslatableObject {
  SortedSet<LibraryItem> libraryitems

  static belongsTo = [librarycategory:LibraryCategory]
  static hasMany = [libraryitems: LibraryItem]
  static constraints = {
  }
}

我的问题是，当我在服务中运行此代码时，我得到了异常“IndexOutOfBoundsException”，detailMessage“Index:1，Size 0”和被抑制的异常“Collections$UnmodifiableRandomAccessList”，值为“size = 0”也不例外，当我在控制器中运行此代码时。异常来自命令 it.addToLibraryitems(libraryitem)，respektive，当我评论这一行时，没有发生异常。谁能给我一个提示，问题可能是什么？

提前致谢。

编辑：

我现在用

初始化了类中的库项

SortedSet<LibraryItem> libraryitems = []

但现在启动应用程序时出现以下错误

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 objectch.fhnw.accelerom.project.library.LibraryCategoryValue
org.springframework.beans.factory.BeanCreationException: 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 objectch.fhnw.accelerom.project.library.LibraryCategoryValue
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: 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 objectch.fhnw.accelerom.project.library.LibraryCategoryValue
    ... 4 more
Caused by: 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 objectch.fhnw.accelerom.project.library.LibraryCategoryValue
    ... 4 more
Caused by: org.hibernate.InstantiationException: could not instantiate test objectch.fhnw.accelerom.project.library.LibraryCategoryValue
    ... 4 more
Caused by: java.lang.reflect.InvocationTargetException
    ... 4 more
Caused by: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object '[]' with class 'java.util.ArrayList' to class 'java.util.SortedSet' due to: groovy.lang.GroovyRuntimeException: Could not find matching constructor for: java.util.SortedSet()
    at ch.fhnw.accelerom.project.library.LibraryCategoryValue.<init>(LibraryCategoryValue.groovy:7)
    ... 4 more

编辑 2：

我还尝试使用

初始化库项

SortedSet<LibraryItem> libraryitems = new TreeSet<LibraryItem>()

但是我又回到了第一个异常“IndexOutOfBoundsException”。我很想知道，当这段代码在控制器中时，为什么没有问题。在这种情况下，服务和控制器有什么区别？

Answer 1

尝试使用事务服务方法：

import grails.transaction.Transactional

class LibraryService {

    @Transactional
    public LibraryItem createLibraryItemWithValues(ProjectItem projectItem) {
        def libraryitem = new LibraryItem()

        libraryitem.name = projectItem.name
        libraryitem.itemtype = projectItem.itemtype.itemtype
        libraryitem.description = projectItem.description

        projectItem.categoryvalues*.librarycategoryvalue.each {
            it.addToLibraryitems(libraryitem)
        }

        return libraryitem.save()
    }
}

由于您正在创建一个新的LibraryItem，它的 ID 将始终为空，直到您保存它。大多数情况下你不需要使用attach()，所以我删除了所有的代码。