我希望使用Jackson对象Mapper获得多个Json对象数组的大小。我可以在不使用Jackson树

Question

<b>Here is Json:</b>

[{"index":"incident","type":"SmbIncident"},
{"index":"incident","type":"SmbIncident"}
]


IndexPortion is class how can i get both Json object size.

IndexPortion = new ObjectMapper（）。readValue（new File（path），    IndexPortion.class）;

Answer 1

首先，您应该为json对象创建一个实体：

public class MyEntity implements Serializable{
    private String index;
    private String type;
    // getter and setter
}

然后你可以使用JsonUtil from this post：

将json数组转换为list

List<MyEntity> entities= JsonUtil.toObject(jsonString,
                            new TypeReference<List<MyEntity>>() {});
int size = entities.size();