为什么 Json 对象在下面的 Json 值之前出现？

Question

我正在尝试使用创建嵌套的 json 对象org.json.simple.JSONObject。为什么 jsonobject 改变顺序？

预期输出：

{  

  "id":"14",   

  "email":"[e-mail]",    

  "Company":{   

    "address":"milton street",   

    "postal code":"cincinnati",   

    "name":"abc"  

  }  

}  

电流输出：

{  

"Company":{   

"address":"milton street",    

"postal code":"cincinnati",    

"name":"abc"  

},   

"id":"14",   

"email":"[e-mail]"  

} 

这是我的代码：

 JSONObject First = new JSONObject();

    First.put("id", "14");

    First.put("email", "[e-mail]");

    JSONObject companydetails = new JSONObject();

    companydetails.put("name", "abc");

    companydetails.put("address", "milton street");

    companydetails.put("postal code", "cincinnati");

    First.put("Company",companydetails);

    System.out.println(First.toString());

Answer 1

使用 google/gson 库JsonObject o=new JsonObject();o.addProperty("id", "14");o.addProperty("email", "[e-mail]");JsonObject companydetails1 = new JsonObject();companydetails1.addProperty("name", "abc");companydetails1.addProperty("address", "milton street");companydetails1.addProperty("postal code", "cincinnati");o.add("Company",companydetails1);System.out.println(o.toString());使用 Maven 回购&nbsp; &nbsp; <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson --><dependency>&nbsp; &nbsp; <groupId>com.google.code.gson</groupId>&nbsp; &nbsp; <artifactId>gson</artifactId>&nbsp; &nbsp; <version>2.3.1</version></dependency>或者用外部jar下载

Answer 2

在此处查看答案：JSON 顺序混淆您不能也不应该依赖 JSON 对象中元素的顺序。来自http://www.json.org/的 JSON 规范：“对象是一组无序的名称/值对”因此，JSON 库可以根据需要自由地重新排列元素的顺序。这不是错误。

Answer 3

JsonObject 不维护顺序，这并不重要，因为您将通过键访问 json。

Answer 4

import com.fasterxml.jackson.annotation.JsonProperty;import com.google.gson.Gson;import com.google.gson.GsonBuilder;import lombok.Builder;import lombok.Getter;import org.junit.Test;public class TestJUnit {&nbsp; &nbsp; @Test&nbsp; &nbsp; public void exec() {&nbsp; &nbsp; &nbsp; &nbsp; Gson gson = new GsonBuilder().disableHtmlEscaping().create();&nbsp; &nbsp; &nbsp; &nbsp; String toPrint = gson.toJson(ToJsonFormat.builder()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .id(14)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .email("[e-mail]")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .company(Company.builder()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .address("milton street")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .postCode("cincinnati")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .name("abc")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .build())&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .build());&nbsp; &nbsp; &nbsp; &nbsp; System.out.println(toPrint);&nbsp; &nbsp; }&nbsp; &nbsp; @Getter&nbsp; &nbsp; @Builder&nbsp; &nbsp; private static class ToJsonFormat {&nbsp; &nbsp; &nbsp; &nbsp; private int id;&nbsp; &nbsp; &nbsp; &nbsp; private String email;&nbsp; &nbsp; &nbsp; &nbsp; private Company company;&nbsp; &nbsp; }&nbsp; &nbsp; @Getter&nbsp; &nbsp; @Builder&nbsp; &nbsp; private static class Company {&nbsp; &nbsp; &nbsp; &nbsp; private String address;&nbsp; &nbsp; &nbsp; &nbsp; @JsonProperty("post code")&nbsp; &nbsp; &nbsp; &nbsp; private String postCode;&nbsp; &nbsp; &nbsp; &nbsp; private String name;&nbsp; &nbsp; }}结果：{"id":14,"email":"[e-mail]","company":{"address":"milton street","post_code":"cincinnati","name":"abc"}}