Is it possible to change the JSON names for Spring Data pageable responses?

Question

I'm trying the Page and Pageable interface from Spring Data. It returns JSON in the following format

{"content":
[... my objects ...],
"last":false,
"totalPages":7,
"totalElements":13,
"size":2,
"number":0,
"sort":null,
"first":true,
"numberOfElements":2}

The questions I have is how can I change the names of these JSON elements?

The company I work for has strict guidelines on service JSON naming conventions, so out of the box this wouldn't work for me, but if it's possible to change these names then I could use it.

Meiko Rachimow · Answer 1 · 2016-04-10T21:45:06.323

Create a class, maybe called PageWrapper, which implements org.springframework.data.domain.Page and has a constructor, which gets another Page as an argument. Delegate all method calls to the wrapped Page instance. After that you can use @JsonProperty annotations to rename the fields in the serialized JSON. Wrap the Page (in fact a PageImpl) instance with an instance of PageWrapper and change the return type of your resource methods to PageWrapper.

score 1 · Answer 2 · edited May 23 '17 at 12:31

1

Try using:

     @Entity
public class City {
   @id
   Long id;
   String name;

   @JsonProperty("label")
   public String getName() { return name; }

   public void setName(String name){ this.name = name; }

   @JsonProperty("value")
   public Long getId() { return id; }

   public void setName(Long id){ this.id = id; }
}

reference

edited May 23 '17 at 12:31

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answered Apr 10 '16 at 21:20

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Hassam Abdelillah · Answer 3 · 2016-04-10T22:04:33.430

As said in last answers the best to do is to use page wrapper.That means you have to build a page that will create a representation of the resource you want to expose.

It will help you to put the links to paginate between content and also to have the metadata ( total of pages, size, number of elements ect.. ) just as with the pageable interface.

Here is a short example. A full example is provided HERE

  public class PagedResource<T> {
  private List<T> content;
  private final Map metadata;
  public PagedResource(Page<T> page, String pageParam, String sizeParam, String sortParam, String sortField) {
    super();
    this.setContent(page.getContent());
    this.metadata = new HashMap();
    List<Link> links = new ArrayList<Link>();
    if (page.hasPrevious()) {
      String path = createBuilder().queryParam(pageParam, page.getNumber() - 1).queryParam(sizeParam, page.getSize()).queryParam(sortParam, sortField).build().toUriString();
      Link previousPageLink = new Link(path, Link.REL_PREVIOUS);
      links.add(previousPageLink);
    }
    if (page.hasNext()) {
      String path = createBuilder().queryParam(pageParam, page.getNumber() + 1).queryParam(sizeParam, page.getSize()).queryParam(sortParam, sortField).build().toUriString();
      Link nextPageLink = new Link(path, Link.REL_NEXT);
      links.add(nextPageLink);
    }
    if (!page.isFirst()) {
      Link firstPageLink = buildPageLink(pageParam, 0, sizeParam, page.getSize(), sortParam, sortField, Link.REL_FIRST);
      links.add(firstPageLink);
    }
    if (!page.isLast()) {
      int lastPage = page.getTotalPages() - 1;
      Link lastPageLink = buildPageLink(pageParam, lastPage, sizeParam, page.getSize(), sortParam, sortField, Link.REL_LAST);
      links.add(lastPageLink);
    }
    Link currentPagelink = buildPageLink(pageParam, page.getNumber(), sizeParam, page.getSize(), sortParam, sortField, Link.REL_SELF);
    links.add(currentPagelink);
    populateMetadata(page, links);
  }
  private void populateMetadata(Page<T> page, List<Link> links) {
    int per_page = page.getSize();
    int totalPages = page.getTotalPages();
    int numberOfPageElements = page.getNumberOfElements();
    metadata.put("numberOfPageElements", numberOfPageElements);
    metadata.put("perPage", per_page);
    metadata.put("totalPages", totalPages);
    metadata.put("links", links);
  }
  private Link buildPageLink(String pageParam, int page, String sizeParam, int size, String sortParam, String sortAttribute, String rel) {
    String path = createBuilder().queryParam(pageParam, page).queryParam(sizeParam, size).queryParam(sortParam, sortAttribute).toUriString();
    Link link = new Link(path, rel);
    return link;
  }
  private ServletUriComponentsBuilder createBuilder() {
    return ServletUriComponentsBuilder.fromCurrentRequestUri();
  }
  public List<T> getContent() {
    return content;
  }
  public void setContent(List<T> content) {
    this.content = content;
  }
  public Map getMetadata() {
    return metadata;
  }
}

Hope it helps !

score 0 · Answer 4 · answered Oct 01 '22 at 09:23

Use the @JsonProperty to rename. Sample below:

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.PropertyNamingStrategies;
import com.fasterxml.jackson.databind.annotation.JsonNaming;
import java.util.Iterator;
import java.util.List;
import java.util.function.Function;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;

public class PageWrapper<T> implements Page<T> {

    private final Page<T> delegate;

    public PageWrapper(@JsonProperty("content") final List<T> content,
                       @JsonProperty("number") final int number,
                       @JsonProperty("size") final int size,
                       @JsonProperty("total_elements") final long totalElements) {
        delegate = new PageImpl<>(content, PageRequest.of(number, size), totalElements);
    }

    public PageWrapper(final List<T> content,
                       final Pageable pageable,
                       final long total) {
        delegate = new PageImpl<>(content, pageable, total);
    }
    @JsonProperty("total_pages")
    @Override
    public int getTotalPages() {
        return delegate.getTotalPages();
    }

    @JsonProperty("total_elements")
    @Override
    public long getTotalElements() {
        return delegate.getTotalElements();
    }

    @JsonProperty("number")
    @Override
    public int getNumber() {
        return delegate.getNumber();
    }

    @JsonProperty("size")
    @Override
    public int getSize() {
        return delegate.getSize();
    }

    @JsonProperty("number_of_elements")
    @Override
    public int getNumberOfElements() {
        return delegate.getNumberOfElements();
    }

    @JsonProperty("content")
    @Override
    public List<T> getContent() {
        return delegate.getContent();
    }

    @JsonProperty("has_content")
    @Override
    public boolean hasContent() {
        return delegate.hasContent();
    }

    @JsonIgnore
    @Override
    public Sort getSort() {
        return delegate.getSort();
    }

    @JsonProperty("is_first")
    @Override
    public boolean isFirst() {
        return delegate.isFirst();
    }

    @JsonProperty("is_last")
    @Override
    public boolean isLast() {
        return delegate.isLast();
    }

    @JsonIgnore
    @Override
    public boolean hasNext() {
        return delegate.hasNext();
    }

    @JsonIgnore
    @Override
    public boolean hasPrevious() {
        return delegate.hasPrevious();
    }

    @JsonIgnore
    @Override
    public Pageable nextPageable() {
        return delegate.nextPageable();
    }

    @JsonIgnore
    @Override
    public Pageable previousPageable() {
        return delegate.previousPageable();
    }

    @Override
    public <U> Page<U> map(final Function<? super T, ? extends U> function) {
        return delegate.map(function);
    }

    @JsonIgnore
    @Override
    public Iterator<T> iterator() {
        return delegate.iterator();
    }
}

Is it possible to change the JSON names for Spring Data pageable responses?

4 Answers4