Java模型的JSON字段映射

Question

发送的JSON:

{
  "Banner": "ABC"
}

Java模型:

...
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonSerialize(include = JsonSerialize.Inclusion.NON_NULL)
public class BannerData implements java.io.Serializable {

    private static final long serialVersionUID = 5664846645733319592L;

    @JsonProperty(value = "Banner")
    private String banner;

    public String getBanner() {
        return banner;
    }

    public void setBanner(String banner) {
        this.banner = banner;
    }
}

控制器:

@RequestMapping(value = {"/GetBanner"}, method = RequestMethod.POST)
@ResponseBody
public ResponseEntity<String> enrollCustomer(@RequestBody BannerData body, HttpServletRequest request) throws Exception {
...
}

请求/GetBanner返回:
客户端发送的请求在语法上是不正确的.

工程确定当JSON变更为(小写字母命名的就是Java字段名):

{
  "banner": "ABC"
}

但是我需要在JSON中使用大写字段命名. 看起来不起作用.
@JsonProperty(value = "Banner")

这是正确的映射吗？

Answer 1

也许你只是试着:

@JsonProperty("Banner")

没有'value ='.我在我的项目中使用它,它实际上按预期工作.

UPDATE

我刚刚创建了一些测试类来测试你的问题的行为.我做了什么:

import org.codehaus.jackson.annotate.JsonIgnoreProperties;
import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.map.annotate.JsonSerialize;


@JsonIgnoreProperties(ignoreUnknown = true)
@JsonSerialize(include = JsonSerialize.Inclusion.NON_NULL)
public class BannerData implements java.io.Serializable {

 private static final long serialVersionUID = 5664846645733319592L;

 @JsonProperty("Banner")
 private String banner;

 public String getBanner() {
     return banner;
 }

 public void setBanner(String banner) {
     this.banner = banner;
 }
}

另一个读json的类:

import org.codehaus.jackson.map.ObjectMapper;
import java.io.File;
import java.io.IOException;

public class BannerReader {
 private static final String JSON_PATH = "pathToYourJson";

 public BannerData readBanner() throws IOException {
    ObjectMapper mapper = new ObjectMapper();
    return mapper.readValue(new File(JSON_PATH), BannerData.class);
 }
}

最后是入口点类:

import java.io.IOException;

public class BannerTest {

 public static void main(String[] args) throws IOException {
     BannerReader reader = new BannerReader();
     BannerData bannerData = reader.readBanner();
     System.out.println(bannerData.getBanner());
 }
}

打印:

ABC

使用依赖:

<dependency>
  <groupId>org.codehaus.jackson</groupId>
  <artifactId>jackson-mapper-asl</artifactId>
  <version>1.9.13</version>
</dependency>

json文件:

{
  "Banner": "ABC"
}

更新2

虽然上述代码不适合您,但请尝试添加

@JsonProperty("Banner")

不仅是私有变量,还有getter/setter对,如:

@JsonProperty("Banner")
private String banner;

@JsonProperty("Banner")
public String getBanner() {
  return banner;
}

@JsonProperty("Banner")
public void setBanner(String banner) {
  this.banner = banner;
}

Answer 2

我建议下面; (如果您使用的是ObjectMapper)

一旦获得了ObjectMapper,就可以使用PascalCase设置PropertyNamingStrategy.这是文档的链接

ObjectMapper mapper = new ObjectMapper();
mapper.setPropertyNamingStrategy(
    PropertyNamingStrategy.PascalCaseStrategy);

如果你不使用ObjectMapper-然后标注您BannerData带班@JsonNaming像below--

@JsonNaming(PropertyNamingStrategy.LowerCaseWithUnderscoresStrategy.class) 
public class BannerData implements java.io.Serializable {

我在github找到了@JsonNaming