Java 对象转 Json

        
            com.fasterxml.jackson.core
            jackson-core
            2.11.2
        
        
            com.fasterxml.jackson.core
            jackson-databind
            2.11.2
        

import java.util.List;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * Json工具类
 */
public class JsonUtils {

    // 定义jackson对象
    private static final ObjectMapper MAPPER = new ObjectMapper();

    /**
     * 将对象转换成json字符串。
     * 
Title: pojoToJson
     * 
Description: 
     * @param data
     * @return
     */
    public static String objectToJson(Object data) {
    	try {
			String string = MAPPER.writeValueAsString(data);
			return string;
		} catch (JsonProcessingException e) {
			e.printStackTrace();
		}
    	return null;
    }
    
    /**
     * 将json结果集转化为对象
     *
     * @param jsonData json数据
     * @param beanType 对象中的object类型
     * @return
     */
    public static  T jsonToPojo(String jsonData, Class beanType) {
        try {
            T t = MAPPER.readValue(jsonData, beanType);
            return t;
        } catch (Exception e) {
        	e.printStackTrace();
        }
        return null;
    }
    
    /**
     * 将json数据转换成pojo对象list
     * 
Title: jsonToList
     * 
Description: 
     * @param jsonData
     * @param beanType
     * @return
     */
    public static List jsonToList(String jsonData, Class beanType) {
    	JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType);
    	try {
    		List list = MAPPER.readValue(jsonData, javaType);
    		return list;
		} catch (Exception e) {
			e.printStackTrace();
		}
    	
    	return null;
    }
    
}