JSONUtil.java

package com.segmentfault.app.utils.json;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.alibaba.fastjson.annotation.JSONField;

import org.json.JSONObject;

import java.lang.reflect.Field;
import java.util.Iterator;


/**
 * Created by geminiwen on 15/4/9.
 */
public class JSONUtil {

    public static <T> T readValue(String content, TypeReference<T> type) {
        return JSON.parseObject(content, type);
    }

    public static String writeValue(Object obj) {
        return JSON.toJSONString(obj);
    }

    public static <T> T decodeJSONObject(JSONObject jsonObject, Class<T> clazz) {
        T instance = null;
        try {
            instance = clazz.newInstance();
            Iterator<String> keys = jsonObject.keys();

            Field[] fields = clazz.getDeclaredFields();

            for(;keys.hasNext();) {
                String key = keys.next();
                for (Field field: fields) {
                    if (field.isAnnotationPresent(JSONField.class)) {
                        JSONField jsonField = field.getAnnotation(JSONField.class);
                        String jsonFieldName = jsonField.name();
                        if (!jsonFieldName.equals(key)) {
                            continue;
                        }
                        if (!jsonField.deserialize()) {
                            break;
                        }
                        Object obj = jsonObject.opt(key);
                        field.setAccessible(true);
                        field.set(instance, obj);
                        break;
                    }

                    if (field.getName().equals(key)) {
                        Object obj = jsonObject.opt(key);
                        field.setAccessible(true);
                        field.set(instance, obj);
                        break;
                    }
                }
            }

        } catch (InstantiationException e) {

        } catch (IllegalAccessException e) {

        }
        return instance;
    }
}