Spring，Java：将通用对象列表作为返回类型传递(Spring, Java : Passing Generic object List as return type)

 我正在开发一个Spring-MVC应用程序，根据用户设置的模式，我必须返回一个Object1或Object2的List。 理想情况下，我可以创建两个控制器方法并适当地发送List，但我想知道是否有任何方法，我可以在该Controller方法中发送任何类型的List。 
 
 控制器方法： 
 
@PreAuthorize("hasRole('ROLE_USER')")
@RequestMapping(value = "/findnotebydays/{days}/{canvasid}/{mode}")
public @ResponseBody List<Inotes> findNotesByDays(@PathVariable("days")int days, @PathVariable("canvasid")int canvasid,
                                                  @PathVariable("mode")boolean mode ){

    if(!mode){
        return this.groupNotesService.findGroupNotesByDays(days,canvasid);
    } else {
        return this.notesService.findNotesByDays(days,canvasid);
    }
}
 
 基本上，如果mode为false，我想返回List<GroupNotes> ，如果mode为true，我想返回List<Notes> 。 我的天真的方法，我认为我可以说它是一个对象并返回，但似乎不起作用。 请让我知道我能做些什么。 非常感谢。 :-) 
 
 更新 
 
 GroupNotes模型类： 
 
@Entity
@Table(name="groupnotes")
public class GroupNotes implements Inotes{

  @Id
    @Column(name="mnoteid")
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "mnote_gen")
    @SequenceGenerator(name = "mnote_gen",sequenceName = "mnote_seq")
    @org.hibernate.annotations.Index(name = "mnoticesidindex")
    private int mnoticesid;

    @Column(name = "mnotetext")
    private String mnotetext;
//Other variables, getters, setters ignored
}
 
 Notes模型类： 
 
@Entity
@Table(name="note")
public class Notes implements Inotes{

    @Id
    @Column(name="noteid")
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "note_gen")
    @SequenceGenerator(name = "note_gen",sequenceName = "note_seq")
    @org.hibernate.annotations.Index(name = "noteidindex")
    private int noticesid;

    @Column(name = "notetext")
    private String notetext;
//Other variables, getters, setters ignored
}
 
 界面信息： 
 
package com.journaldev.spring.model;


public interface Inotes {
}

I am working on a Spring-MVC application in which depending upon the mode set by the user, I have to return a List of either Object1 or Object2. Ideally, I can create two controller methods and send the List appropriately, but I would like to know is there any way, I can send any type of List in that Controller method. 
 
Controller method :
 
@PreAuthorize("hasRole('ROLE_USER')")
@RequestMapping(value = "/findnotebydays/{days}/{canvasid}/{mode}")
public @ResponseBody List<Inotes> findNotesByDays(@PathVariable("days")int days, @PathVariable("canvasid")int canvasid,
                                                  @PathVariable("mode")boolean mode ){

    if(!mode){
        return this.groupNotesService.findGroupNotesByDays(days,canvasid);
    } else {
        return this.notesService.findNotesByDays(days,canvasid);
    }
}
 
Basically, if mode is false, I want to return List<GroupNotes> and if mode is true, I would like to return List<Notes>. My naive approach that I thought I can just say it is an Object and return, but doesn't seem to work. Kindly let me know what I can do. Thanks a lot. :-)
 
Update
 
GroupNotes model class :
 
@Entity
@Table(name="groupnotes")
public class GroupNotes implements Inotes{

  @Id
    @Column(name="mnoteid")
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "mnote_gen")
    @SequenceGenerator(name = "mnote_gen",sequenceName = "mnote_seq")
    @org.hibernate.annotations.Index(name = "mnoticesidindex")
    private int mnoticesid;

    @Column(name = "mnotetext")
    private String mnotetext;
//Other variables, getters, setters ignored
}
 
Notes model class :
 
@Entity
@Table(name="note")
public class Notes implements Inotes{

    @Id
    @Column(name="noteid")
    @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "note_gen")
    @SequenceGenerator(name = "note_gen",sequenceName = "note_seq")
    @org.hibernate.annotations.Index(name = "noteidindex")
    private int noticesid;

    @Column(name = "notetext")
    private String notetext;
//Other variables, getters, setters ignored
}
 
Interface Inotes :
 
package com.journaldev.spring.model;


public interface Inotes {
}

原文：https://stackoverflow.com/questions/30868002