jackson的使用

jackson工具类

package com.booway.util;

import java.util.List;

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

/**
 * json工具
 * @author wzh
 *
 */
public class JsonUtils {

    private static final ObjectMapper MAPPER = new ObjectMapper();

    public static String objectToJson(Object data) {
        String string = null;
        try {
            string = MAPPER.writeValueAsString(data);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return string;
    }
    
    public static <T> T jsonToPojo(String jsonData, Class<T> beanType) {
        T t = null;
        try {
           t = MAPPER.readValue(jsonData, beanType);
            return t;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return t;
    }
    
    public static <T>List<T> jsonToList(String jsonData, Class<?> target, Class<T> beanType) {
        
        JavaType javaType = MAPPER.getTypeFactory().constructParametricType(target, beanType);
        List<T> list = null;
        try {
            list = MAPPER.readValue(jsonData, javaType);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return list;
    }
    
    private static BwjsResult build(boolean successful, String message, Object data) {
        
        return new BwjsResult(successful, message, data);
    }
    
    public static BwjsResult formatToPojo(String jsonData, Class<?> clazz) {
        try {
            if (clazz == null) {
                return MAPPER.readValue(jsonData, BwjsResult.class);
            }
            JsonNode jsonNode = MAPPER.readTree(jsonData);
            JsonNode data = jsonNode.get("data");
            Object obj = null;
            if (clazz != null) {
                if (data.isObject()) {
                    obj = MAPPER.readValue(data.traverse(), clazz);
                } else if (data.isTextual()) {
                    obj = MAPPER.readValue(data.asText(), clazz);
                }
            }
            return build(jsonNode.get("successful").booleanValue(), jsonNode.get("msg").asText(), obj);
        } catch (Exception e) {
            return null;
        }
    }

    public static BwjsResult format(String json) {
        try {
            return MAPPER.readValue(json, BwjsResult.class);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static BwjsResult formatToList(String jsonData, Class<?> clazz) {
        try {
            JsonNode jsonNode = MAPPER.readTree(jsonData);
            JsonNode data = jsonNode.get("data");
            Object obj = null;
            if (data.isArray() && data.size() > 0) {
                obj = MAPPER.readValue(data.traverse(),
                        MAPPER.getTypeFactory().constructCollectionType(List.class, clazz));
            }
            return build(jsonNode.get("successful").booleanValue(), jsonNode.get("msg").asText(), obj);
        } catch (Exception e) {
            return null;
        }
    }
}