Java 我们不能在GAE中使用集合或集合作为返回类型吗？

在我的代码中，我使用了

Set

作为函数

addamp（）

的返回类型

所以，我遇到了一个编译错误。错误是：

Compiling module com.employeedepartmentgae.Employeedepartmentgae Refreshing module from source Validating newly compiled units Removing units with errors [ERROR] Errors in 'file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingServiceAsync.java' [ERROR] Line 6: The import com.employeedepartmentgae.server.domainobject.Employee cannot be resolved [ERROR] Line 18: Employee cannot be resolved to a type [ERROR] Errors in 'file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingService.java' [ERROR] Line 6: The import com.employeedepartmentgae.server.domainobject.Employee cannot be resolved [ERROR] Line 20: Employee cannot be resolved to a type [ERROR] Errors in 'file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/EmployeeWidget.java' [ERROR] Line 12: The import com.employeedepartmentgae.server.domainobject.Employee cannot be resolved [ERROR] Line 75: The method addEmp(String, String, String, AsyncCallback>) from the type GreetingServiceAsync refers to the missing type Employee [ERROR] Line 75: The type new AsyncCallback>(){} must implement the inherited abstract method AsyncCallback>.onSuccess(Set) [ERROR] Line 75: Employee cannot be resolved to a type [ERROR] Line 94: The method onSuccess(Set) of type new AsyncCallback>(){} must override or implement a supertype method [ERROR] Line 94: Employee cannot be resolved to a type [ERROR] Line 96: Employee cannot be resolved to a type [ERROR] Line 96: Employee cannot be resolved to a type [ERROR] Line 98: Employee cannot be resolved to a type Removing invalidated units [WARN] Compilation unit 'file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/Employeedepartmentgae.java' is removed due to invalid reference(s): [WARN] file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/EmployeeWidget.java [WARN] Compilation unit 'file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/DepartmentWidget.java' is removed due to invalid reference(s): [WARN] file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingService.java [WARN] file:/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingServiceAsync.java Computing all possible rebind results for 'com.employeedepartmentgae.client.Employeedepartmentgae' Rebinding com.employeedepartmentgae.client.Employeedepartmentgae Checking rule [ERROR] Unable to find type 'com.employeedepartmentgae.client.Employeedepartmentgae' [ERROR] Hint: Previous compiler errors may have made this type unavailable [ERROR] Hint: Check the inheritance chain from your module; it may not be inheriting a required module or a module may not be adding its source path entries properly 编译模块com.employeedepartmentgae.employeedepartmentgae 从源刷新模块 验证新编译的单元 删除有错误的单元 “文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingServiceAsync.java”中的[ERROR]错误 [错误]第6行：无法解析导入com.employeedepartmentgae.server.domainobject.Employee [错误]第18行：无法将员工解析为类型 “文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingService.java”中的[ERROR]错误 [错误]第6行：无法解析导入com.employeedepartmentgae.server.domainobject.Employee [错误]第20行：无法将员工解析为类型 “文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/EmployeeWidget.java”中的[ERROR]错误 [错误]第12行：无法解析导入com.employeedepartmentgae.server.domainobject.Employee [错误]第75行：GreetingServiceAsync类型中的方法addamp（String，String，String，AsyncCallback>）引用了缺少的Employee类型 [错误]第75行：类型new AsyncCallback>（）{}必须实现继承的抽象方法AsyncCallback>.onSuccess（Set） [错误]第75行：无法将员工解析为类型 [错误]第94行：new AsyncCallback>（）{}类型的onSuccess（Set）方法必须重写或实现超类型方法 [错误]第94行：无法将员工解析为类型 [错误]第96行：无法将员工解析为类型 [错误]第96行：无法将员工解析为类型 [错误]第98行：无法将员工解析为类型 删除失效单元 [警告]编译单元文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/employeedepartmentgae.java因引用无效而被删除： [警告]文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/EmployeeWidget.java [警告]编译单元文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/DepartmentWidget.java因引用无效而被删除： [警告]文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingService.java [警告]文件：/home/wissen18/employeedepartmentgae/src/com/employeedepartmentgae/client/GreetingServiceAsync.java 正在计算“com.employeedepartmentgae.client.employeedepartmentgae”的所有可能重新绑定结果 重新绑定com.employeedepartmentgae.client.employeedepartmentgae 检查规则 [错误]找不到类型'com.employeedepartmentgae.client.employeedepartmentgae' [错误]提示：以前的编译器错误可能导致此类型不可用 [错误]提示：检查模块中的继承链；它可能没有继承所需的模块，或者模块可能没有正确添加其源路径项

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因此，请帮助我……

这不是GAE问题，但您没有提到您使用的GWT存在问题

从堆栈跟踪来看，Employee类似乎使用了未正确实现的AsyncCallback

…
[错误]第75行：类型new AsyncCallback>（）{}必须实现继承的抽象方法AsyncCallback>.onSuccess（Set） ...

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我建议您查看GWT文档并创建HelloWorld应用程序，它将在其中创建一个RPC示例。

您可以发布您的实体代码吗？还有您的数据访问代码？已解决-不是GAE问题，是GWT问题此问题是否仍处于活动状态？？？实际上，问题似乎出在

Employee

类上，而不是

AsyncCallback

的实现上，因为错误消息说“Employee无法解析为类型”--我们可以查看Employee类来了解问题所在吗？@Jason Hall他正在Employee类中调用AsyncCallback。他的部分实现很差，不允许员工编译。我相信你们，但可能还有其他问题。看到一些代码提示会很有帮助！提示！