jackson工具类(JsonUtil )

springboot用的就是这个

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class JsonUtil {
    static ObjectMapper objectMapper = new ObjectMapper();
    static {
        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);// 允许pojo中有在json串中不存在的字段
        objectMapper.configure(JsonParser.Feature.ALLOW_COMMENTS, true);// 允许有注释
    }
    
    public static <T>T parseObject(InputStream inputStream, Class<T> tClass)  {
        Reader reader = new InputStreamReader(inputStream);
        try {
            return objectMapper.readValue(reader, tClass);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static <T>T parseObject(String json,Class<T> tClass){
        try {
            return objectMapper.readValue(json,tClass);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static String toJsonString(Object object){
        try {
            return objectMapper.writeValueAsString(object);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static <T>List<T> parseList(String json,Class<T> tClass) {
        JavaType javaType = objectMapper.getTypeFactory().constructParametricType(List.class, tClass);
        try {
            List<T> list  = objectMapper.readValue(json, javaType);
            return list;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

}