json格式转为 map 和 bean

JSONUtils  工具类

package com.xxx.qrcode;

import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.codehaus.jackson.map.ObjectMapper;

import net.sf.json.JSONException;
import net.sf.json.JSONObject;

/**
 *
 * @ClassName:JSONUtils
 * @Description:TODO(这里用一句话描述这个类的作用    JSON工具类)
 * @author: ZHOUPAN
 * @date 2018年10月24日 上午11:58:29
 *
 * @Copyright: 2018 www.xxx.com Inc. All rights reserved.
 */
public class JSONUtils {
     private static ObjectMapper mapper;
    /**
     * 获取ObjectMapper实例
     * @param createNew 方式：true，新实例；false,存在的mapper实例
     * @return
     */
    public static synchronized ObjectMapper getMapperInstance(boolean createNew) {
        if (createNew) {
            return new ObjectMapper();
        } else if (mapper == null) {
            mapper = new ObjectMapper();
        }
        return mapper;
    }

    /**
     * 将java对象转换成json字符串
     * @param obj 准备转换的对象
     * @return json字符串
     * @throws Exception
     */
    public static String beanToJson(Object obj) throws IOException {
        ObjectMapper objectMapper = getMapperInstance(false);
        String json =objectMapper.writeValueAsString(obj);
        return json;
    }

    /**
     * 将java对象转换成json字符串
     * @param obj 准备转换的对象
     * @param createNew ObjectMapper实例方式:true，新实例;false,存在的mapper实例
     * @return json字符串
     * @throws Exception
     */
    public static String beanToJson(Object obj,Boolean createNew) throws IOException {
        ObjectMapper objectMapper = getMapperInstance(createNew);
        String json =objectMapper.writeValueAsString(obj);
        return json;
    }

    /***
     *
     * @Title: jsonToMap
     * @Description: TODO(将JSON字符串转为Map)
     * @author: ZHOUPAN
     * @param: @param jsonString
     *                                 JSON字符串
     * @param: @throws JSONException
     *                                 异常处理
     * @return: Map<String,Object>
     *                                 返回Map
     * @throws
     */
    public static Map<String, Object> jsonToMap(String jsonString) throws JSONException {
        JSONObject jsonObject = JSONObject.fromObject(jsonString);
        Map<String, Object> result = new HashMap<String, Object>();
        Iterator<?> iterator = jsonObject.keys();
        String key = null;
        String value = null;
        while (iterator.hasNext()) {
            key = (String) iterator.next();
            value = jsonObject.getString(key);
            result.put(key, value);
        }
        return result;
    }

    /**
     *
     * @Title: jsonToBean
     * @Description: TODO(将JSON字符创转为Bean)
     * @author: ZHOUPAN
     * @param: @param jsonString
     * @param: @param model
     * @param: @return
     * @param: @throws JSONException
     * @return: T
     * @throws
     */
    @SuppressWarnings({ "static-access", "unchecked" })
    public static <T> T jsonToBean(String jsonString, Class<T> model) throws JSONException {
        JSONObject jsonObject = JSONObject.fromObject(jsonString);
        Object object = jsonObject.toBean(jsonObject, model);
        return (T) object;
    }
}

原文地址：https://www.cnblogs.com/zhou-pan/p/9842808.html