JSON与JAVA数据的相互转换

http://www.cnblogs.com/linjiqin/archive/2011/09/19/2181408.html

import net.sf.json.JSONArray;

import net.sf.json.JSONException;

import net.sf.json.JSONObject;

import net.sf.json.JSONSerializer;

    /**

     * json对象转换为java对象

     *

     * @throws JSONException

     */

    @Test

    public void jsonToJava(){

        String json="[{\"addTime\":\"2011-09-19 14:23:02\",\"iccid\":\"1111\",\"id\":0,\"imei\":\"2222\",\"imsi\":\"3333\",\"phoneType\":\"4444\",\"remark\":\"aaaa\",\"tel\":\"5555\"}]";

        //接收{}对象，此处接收数组对象会有异常

        if(json.indexOf("[")!=-1){

            json=json.replace("[", "");

        }

        if(json.indexOf("]")!=-1){

            json=json.replace("]", "");

        }

        JSONObject obj=new JSONObject().fromObject(json);

        SimInfo simInfo=(SimInfo)JSONObject.toBean(obj, SimInfo.class);

        System.out.println("obj: "+simInfo);

        System.out.println(simInfo.getAddTime());

        System.out.println(simInfo.getIccid());

        System.out.println(simInfo.getImei());

        System.out.println(simInfo.getImsi());

        System.out.println(simInfo.getPhoneType());

        System.out.println(simInfo.getRemark());

        System.out.println(simInfo.getTel());

        System.out.println(simInfo.getId());

        DaoFactory.getSimInfoDao().add(simInfo);

    }

    /**

     * 将json转换为java集合对象

     */

    @Test

    public void jsonToJavas(){

        String jsons="[{\"addTime\":\"2011-09-19 14:23:02\",\"iccid\":\"1111\",\"id\":0,\"imei\":\"2222\",\"imsi\":\"3333\",\"phoneType\":\"4444\",\"remark\":\"aaaa\",\"tel\":\"5555\"}," +

                     "{\"addTime\":\"2011-11-11 14:23:02\",\"iccid\":\"2222\",\"id\":0,\"imei\":\"2222\",\"imsi\":\"3333\",\"phoneType\":\"4444\",\"remark\":\"aaaa\",\"tel\":\"5555\"}]";

        List<SimInfo> simInfos = getJavaCollection(new SimInfo(),jsons);

        System.out.println(simInfos.size());

        for(SimInfo simInfo:simInfos){

            System.out.println("addTime: "+simInfo.getAddTime());

            System.out.println("=========");

        }

    }

    /**

     * 封装将json对象转换为java集合对象

     *

     * @param <T>

     * @param clazz

     * @param jsons

     * @return

     */

    private <T> List<T> getJavaCollection(T clazz, String jsons) {

        List<T> objs=null;

        JSONArray jsonArray=(JSONArray)JSONSerializer.toJSON(jsons);

        if(jsonArray!=null){

            objs=new ArrayList<T>();

            List list=(List)JSONSerializer.toJava(jsonArray);

            for(Object o:list){

                JSONObject jsonObject=JSONObject.fromObject(o);

                T obj=(T)JSONObject.toBean(jsonObject, clazz.getClass());

                objs.add(obj);

            }

        }

        return objs;

    }

    /**

     * java对象转换为json对象

     *

     * @throws JSONException

     */

    @Test

    public void javaToJson(){

        SimInfo simInfo=new SimInfo();

        simInfo.setAddTime(UtilTool.dateToStr(new Date(), null));

        simInfo.setIccid("1111");

        simInfo.setImei("2222");

        simInfo.setImsi("3333");

        simInfo.setPhoneType(4);

        simInfo.setRemark("aaaa");

        simInfo.setTel("5555");

        //java对象转换为json对象

        String json=new JSONArray().fromObject(simInfo).toString();

        //json: [{"addTime":"2011-09-19 14:23:02","iccid":"1111","id":0,"imei":"2222","imsi":"3333","phoneType":"4444","remark":"aaaa","tel":"5555"}]

        System.out.println("json: "+json);

    }

jackson-core-asl-1.7.2.jar

jackson-mapper-asl-1.7.2.jar

 //将一个Java对象转换成JSON

            StringWriter writer = new StringWriter();

            ObjectMapper mapper = new ObjectMapper();

            mapper.writeValue(writer, simInfo);

            String json=writer.toString();

基于json-lib.jar包Json实例程序

1.JSONObject to DynaBean

String json = "{name=\"json\",bool:true,int:1,double:2.2}";

JSONObject jsonObject = JSONObject.fromObject(json);

//抽象的写法：DynaBean bean = (DynaBean) JSONSerializer.toJava( jsonObject );

Object bean = JSONObject.toBean(jsonObject);

//Object bean1 = JSONSerializer.toJava(jsonObject);

assertEquals(jsonObject.get("name"), PropertyUtils.getProperty(bean, "name"));

assertEquals(jsonObject.get("bool"), PropertyUtils.getProperty(bean, "bool"));

assertEquals(jsonObject.get("int"), PropertyUtils.getProperty(bean, "int"));

assertEquals(jsonObject.get("double"), PropertyUtils.getProperty(bean, "double"));

2.JSONObject to JavaBean

String json = "{name:\"zhangsan\",age:25,hight:1.72,sex:true}";

JSONObject jsonObject = JSONObject.fromObject(json);

UserBean bean = (UserBean) JSONObject.toBean(jsonObject, UserBean.class);

System.out.println(jsonObject);

理论上，这样就可以了，但时，有异常Caused by: java.lang.NoSuchMethodException: com.json.Json$UserBean.<init>()

3.JSONArray to List

String json = "[\"first\",\"second\"]";

JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON(json);

List output = (List) JSONSerializer.toJava(jsonArray);

4.JSONArray to array

String json = "[\"first\",\"second\"]";

JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON(json);

JsonConfig jsonConfig = new JsonConfig();

jsonConfig.setArrayMode(JsonConfig.MODE_OBJECT_ARRAY);

Object[] output = (Object[]) JSONSerializer.toJava(jsonArray, jsonConfig);

Object[] expected = new Object[] { "first", "second" };

ArrayAssertions.assertEquals(expected, output);

5.JSON 字符串 专为 JavaBean（刘慧斌demo 演示需要的jar包在附件里）

String str="[{\"id\":\"328\",\"mestype\":\"inbox\"},{\"id\":\"327\",\"mestype\":\"inbox\"},{\"id\":\"279\",\"mestype\":\"already\"},{\"id\":\"278\",\"mestype\":\"already\"},{\"id\":\"277\",\"mestype\":\"already\"},{\"id\":\"310\",\"mestype\":\"inbox\"},{\"id\":\"308\",\"mestype\":\"inbox\"},{\"id\":\"305\",\"mestype\":\"inbox\"},{\"id\":\"304\",\"mestype\":\"inbox\"},{\"id\":\"303\",\"mestype\":\"inbox\"}]";

  JSONArray  jsonArray=(JSONArray) JSONSerializer.toJSON(str);

  List list=(List)JSONSerializer.toJava(jsonArray);

        for (Object  obj: list) {

         JSONObject jsonObject = JSONObject.fromObject(obj);

      MessageBean bean = (MessageBean) JSONObject.toBean(jsonObject, MessageBean.class);

   String id=bean.getId()+"";

   String type=bean.getMestype();

   System.out.println(id+" "+type);

  }

  System.out.println(list.size());