Jackson ObjectMapper：如何省略（忽略）null 数组元素 [null]

Question

I have Json array containing null value in array.

{
  myArray: [ null ]
}

How to configure Jackson ObjectMapper to ignore such null array elements - as if it was empty array [] ?

Constrains:

• No control of source class - it is a third party class
• Array element type is unknown upfront
• Array(s) name is unknown upfront

Answer 1

You can use contentNulls property from JsonSetter annotation. Your POJO class could look like below:

class ArrayWrapper {
    private List<String> myArray;

    @JsonSetter(contentNulls = Nulls.SKIP)
    public void setMyArray(List<String> myArray) {
        this.myArray = myArray;
    }

    public List<String> getMyArray() {
        return myArray;
    }
}

See also:

• How to exclude null list items with Jackson

Answer 2

Maybe @JsonIclude works?

   @JsonInclude(value=Include.NON_EMPTY, content=Include.NON_NULL)

http://fasterxml.github.io/jackson-annotations/javadoc/2.9/com/fasterxml/jackson/annotation/JsonInclude.html?is-external=true