我是Spring的新手,并跟随http://spring.io/guides/gs/consuming-rest的示例。
我注意到他们还没有映射http://graph.facebook.com/pivotalsoftware中的所有JSON元素,因此我想稍微扩展一下示例。对于此示例,我想添加“点赞”和“ were_here_count”,就像在Page.java中那样:
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties(ignoreUnknown = true)
public class Page {
private String name;
private String about;
private String phone;
private String website;
private int were_here_count;
private int likes;
public String getName() {return name;}
public String getAbout() {return about;}
public String getPhone() {return phone;}
public String getWebsite() {return website;}
public int getVisitCount() {return were_here_count;}
public int getLikes() {return likes;}
}
并在Application.java中进行以下更改:
import org.springframework.web.client.RestTemplate;
public class Application {
public static void main(String args[]) {
RestTemplate restTemplate = new RestTemplate();
Page page = restTemplate.getForObject("http://graph.facebook.com/pivotalsoftware", Page.class);
System.out.println("Name: " + page.getName());
System.out.println("About: " + page.getAbout());
System.out.println("Phone: " + page.getPhone());
System.out.println("Website: " + page.getWebsite());
System.out.println("Visit count: " + page.getVisitCount());
System.out.println("Likes: " + page.getLikes());
}
}
我以为映射是通过元素名称完成的,并且对于“喜欢”有效,但对于“ were_here_count”却无效。输出:
Name: Pivotal
About: Pivotal is enabling the creation of modern software applications that leverage big & fast data – on a single, cloud independent platform.
Phone: (650) 286-8012
Website: http://www.pivotal.io
Visit count: 0
Likes: 1175
are_here_count当前为60。我猜默认转换器不喜欢变量名中的下划线。因此,我使用了getForObject的重载版本,提供了自己的映射,如下所示:
package hello;
import java.util.HashMap;
import java.util.Map;
import org.springframework.web.client.RestTemplate;
public class Application {
public static void main(String args[]) {
RestTemplate restTemplate = new RestTemplate();
Map<String, String> variables = new HashMap<String, String>(3);
variables.put("name", "name");
variables.put("about", "about");
variables.put("phone", "phone");
variables.put("website", "website");
variables.put("were_here_count", "were_here_count");
variables.put("likes", "likes");
Page page = restTemplate.getForObject("http://graph.facebook.com/pivotalsoftware", Page.class, variables);
System.out.println("Name: " + page.getName());
System.out.println("About: " + page.getAbout());
System.out.println("Phone: " + page.getPhone());
System.out.println("Website: " + page.getWebsite());
System.out.println("Visit count: " + page.getVisitCount());
System.out.println("Likes: " + page.getLikes());
}
}
但是一切都无济于事。我在这里看到了一些有关自定义JSON转换器的示例,但并不太了解它们-另外,这是一个简单得多的示例,我不能通过简单的变量名字符串字符串映射来完成此操作吗?
任何人都知道如何执行此操作,并愿意向我展示如何构建自定义转换器以及必要的步骤是什么?谢谢! :)
最佳答案
尝试在Page
类中添加一些Jackson's annotations来帮助反序列化JSON。您应该能够告诉Jackson(默认情况下将在Spring中处理JSON的序列化/反序列化),响应JSON中的哪些属性映射到您的POJO属性。
public class Page {
...
@JsonProperty("were_here_count")
private int wereHereCount;
...
}
如果您不确定返回什么属性,另一种选择是将JSON映射到
Map
:Map<String,Object> map = restTemplate.getForObject("http://graph.facebook.com/pivotalsoftware", Map.class);
for (Map.Entry entry: response.entrySet()){
// do stuff...
}
有时,这是在响应JSON令人费解或不容易反序列化时进行自定义对象映射的更简单方法。
关于java - Spring RestTemplate自定义映射,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/25921573/