json字符串与pojo对象，list集合的转换

import java.util.List;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * json数据与对象转换
 */
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
     */
    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
     */
    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/map
     */
    public static List jsonToList(String jsonData, Class beanType) {
    	JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType);
    	//如果是Map类型  MAPPER.getTypeFactory().constructParametricType(HashMap.class,String.class, beanType); 
    	try {
    		//是否强制让非数组模式的json字符串与java集合类型相匹配，默认是false，这里改为true
    		MAPPER.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
    		List list = MAPPER.readValue(jsonData, javaType);
    		return list;
		} catch (Exception e) {
			e.printStackTrace();
		}    	
    	return null;
    }    
}