如何从spring REST Controller获取geoJSON？ [英] How to get geoJSON from spring REST Controller?

问题描述

我正在使用java（Spring-4.1.5 + Hibernate-4.3.8）和OpenLayers开发GIS应用程序。对于这个项目，我使用 GeoTools-13RC ， HibernateSptial-4.3 ， jts-1.13 和 jackson-2.5 。
在这个项目中，我在客户端和服务器中有一个层，我在一个类中保存了这个层的功能。我在下面定义了这个类：

I am developing a GIS application with java(Spring-4.1.5 + Hibernate-4.3.8) and OpenLayers. For this project I use GeoTools-13RC, HibernateSptial-4.3, jts-1.13 and jackson-2.5. In this project, I have a layer in client side and in server, I save the features of this layer in a class. I defined the class below:

@Entity
@Table(name="MyPoint")
public class MyPoint
{
    @id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long Id;

    @Column
    private String name;

    @Type(type = "org.hibernate.spatial.GeometryType")
    @Column(name = "the_geom")
    private Point geometry;

    /*
    *
    Getter and Setter
    *
    */
}

在启动应用程序时，我需要在客户端初始化该层。为此，我需要从服务器端返回一个json字符串到该层的客户端。我不想使用 ST_AsGeoJson 或其他匹配。 我使用Spring REST控制器返回我的实体。

In start up of application, I need to init the layer in client side. for this, I need return from server side a json string to client for this layer. I don't want to use ST_AsGeoJson or other matches. I use Spring REST controller for returning my Entity.

我该怎么做？

推荐答案

返回对客户的回复

您需要创建一个资源来公开你的客户。关于这个主题有一些很好的 Spring文档，以及几种不同的方法做到这一点，但基本上是这样的：

Returning a Response to the Client

You will need to create a resource to expose to your client. There is some good Spring documentation on this topic, and a couple of different ways to do it, but essentially something like this:

@Component
@Path("/my_points")
public class MyPoints {

    private PointService pointService;

    @GET
    @Path("{pointId}")
    public Response getPoint(@PathParam("pointId") String pointId) {
        return Response.ok(pointService.getById(pointId)).build();
    }
}

构建JSON

您应该使用Jackson构建您的JSON。如果您构建Spring资源，那么在构造响应时，Jackson可能会默认使用。为了让您了解如何手动将对象转换为JSON：

Building JSON

You should use Jackson to build your JSON. If you build a Spring resource then Jackson will likely be used by default when constructing a response. To give you an idea of how to translate an object to JSON manually:

@Test
public void serializingAnObjectToJson() throws Exception {
    // Create a mapper that translates objects to json/xml/etc using Jackson.
    ObjectMapper om = new ObjectMapper();

    MyPoint point = new MyPoint(223l, "Superman");

    // Creates a JSON representation of the object
    String json = om.writeValueAsString(point);

    // Create a JAX-RS response with the JSON as the body
    Response response = Response.ok(json).build();
}

这篇关于如何从spring REST Controller获取geoJSON？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！