具有MongoDB POST和GET记录的Spring控制器(Spring controller with MongoDB POST and GET records)

 当我想在我的数据库中发布并检索它时，我需要帮助了解我应该如何以及为什么要使用控制器。 当我只使用Post.java和PostRepository.java时，它似乎在我插入数据以及在我的“/ posts”路径中检索整个数据库时起作用。 在文件里面我有一个包含所有条目的posts数组。 
 
 Post.java 
 
public class Post {

@Id private long id;

private String content;
private String time;
private String gender;  
private String age;


// Constructors

public Post() {

}

public Post(long id, String content, String time, String gender, String age) {
    this.id = id;
    this.content = content;
    this.time = time;
    this.gender = gender;
    this.age = age;
}

// Getters

public String getContent() {
    return content;
}

public long getId() {
    return id;
}

public String getTime() {
    return time;
}

public String getGender() {
    return gender;
}

public String getAge() {
    return age;
}
 
 PostRepository.java 
 
@RepositoryRestResource(collectionResourceRel = "posts", path = "posts")
public interface PostRepository extends MongoRepository<Post, String> {

List<Post> findPostByContent(@Param("content") String content);
}
 
 PostController.java 
 
@RestController
public class PostController {    

private final AtomicLong counter = new AtomicLong();

//Insert post in flow 
@RequestMapping(value="/posts", method = RequestMethod.POST)
public Post postInsert(@RequestBody Post post) {
    return new Post(counter.incrementAndGet(), post.getContent(), post.getTime(), post.getGender(), post.getAge());
}

//Get post in flow
@RequestMapping(value="/posts", method = RequestMethod.GET)
public Post getPosts() {
    return null;  //here I want to return all posts made using postInsert above.
}
}
 
 当我使用我的控制器时，我可以发布数据但它没有保存在json文件中，所以当我重新启动我的应用程序时，我再次从id：1开始。 但是，如果没有控制器，则会保存数据。 为什么会这样？ 如何安排以便控制器保存数据？ 我知道这可能是一个愚蠢的问题，但我不知道该怎么办。 

I need help understanding how and why I should use controllers when I want to post something in my DB and retrieving it. When I only use Post.java and PostRepository.java, it seems to work when I insert data as well as retrieving the entire database in my "/posts" path. Inside the file I have a posts array containing all the entries.
 
Post.java
 
public class Post {

@Id private long id;

private String content;
private String time;
private String gender;  
private String age;


// Constructors

public Post() {

}

public Post(long id, String content, String time, String gender, String age) {
    this.id = id;
    this.content = content;
    this.time = time;
    this.gender = gender;
    this.age = age;
}

// Getters

public String getContent() {
    return content;
}

public long getId() {
    return id;
}

public String getTime() {
    return time;
}

public String getGender() {
    return gender;
}

public String getAge() {
    return age;
}
 
PostRepository.java
 
@RepositoryRestResource(collectionResourceRel = "posts", path = "posts")
public interface PostRepository extends MongoRepository<Post, String> {

List<Post> findPostByContent(@Param("content") String content);
}
 
PostController.java
 
@RestController
public class PostController {    

private final AtomicLong counter = new AtomicLong();

//Insert post in flow 
@RequestMapping(value="/posts", method = RequestMethod.POST)
public Post postInsert(@RequestBody Post post) {
    return new Post(counter.incrementAndGet(), post.getContent(), post.getTime(), post.getGender(), post.getAge());
}

//Get post in flow
@RequestMapping(value="/posts", method = RequestMethod.GET)
public Post getPosts() {
    return null;  //here I want to return all posts made using postInsert above.
}
}
 
When I use my controllers I can post data but it is not saved in a json file so when I restart my application I start from id: 1 again. However, without the controller the data is saved. Why is this happening? How can I arrange so that with controllers the data is saved as well? I know this might be a stupid question but I don't know what to do.

原文：https://stackoverflow.com/questions/36691785