Jackson - Java bean to JSON string : uppercase variable converted into lowercase in JSON

Question

I am converting Java bean to JSON string using writeValueAsString method of ObjectMapper where uppercase variables from Java bean is being changed to lowercase in JSON strin

Answer 1

Following jars have been used:

1. jackson-core-2.7.4.jar
2. jackson-annotations-2.7.4.jar
3. jackson-databind-2.7.4.jar

Step 1: Please write following Mixin as follows:

import java.util.ArrayList;
import com.fasterxml.jackson.annotation.JsonProperty;

public abstract class MixIn {
    @JsonProperty("PNRNumber")
    abstract String getPNRNumber();

    @JsonProperty("XId")
    abstract int getXId();

    @JsonProperty("minPriced")
    abstract ArrayList getMinPriced();
}

Step 2: Please write your Module as follows:-

import com.fasterxml.jackson.databind.module.SimpleModule;

public class MyModule extends SimpleModule{
  public MyModule() {
    super("ModuleName");
  }
  @Override
  public void setupModule(SetupContext context){
    context.setMixInAnnotations(BaseBean.class, MixIn.class);   
  }
}

Step 3: Now its time to get json String as follows:

TermBean bean1=new TermBean("JSON");
TermBean bean2=new TermBean("simple");
ArrayList list=new ArrayList();
        list.add(bean1);
        list.add(bean2);
BaseBean bb=new BaseBean();
        bb.setXId(11);
        bb.setPNRNumber("123456789");
        bb.setMinPriced(list);

ObjectMapper mapper = new ObjectMapper();
Module myModule = new MyModule();
mapper.registerModule(myModule);        
String jsonInString = mapper.writeValueAsString(bb);      
System.out.printf( "JSON: %s", jsonInString ); 

Output:

JSON: {"XId":11,"PNRNumber":"123456789","minPriced":[{"name":"JSON"},{"name":"simple"}]}

Hope this helps.

Answer 2

Add Json Property with required keycase. Create variable with lowercase.

public class BaseBean {

@JsonProperty("XId")
private int xId;
..
}

Hope this will help