org.json.JSONObject将对象转换成json

来源：互联网发布：2016年8月淘宝消保新规编辑：程序博客网时间：2024/06/02 03:53

下面写的是JSON转换的工具类

public class ApiJSONUtil {/** * 将json字符串转换成实体POJO *  * @param jsonStr * @param obj * @return * @throws Exception */public static <T> Object JSONToObj(String jsonStr, Class<T> obj)throws Exception {T t = null;ObjectMapper objectMapper = new ObjectMapper();t = objectMapper.readValue(jsonStr, obj);return t;}/** * 将实体POJO转化为JSON对象 该方法不要用于将List<T>对象转换成json对象 * 因为如果对象的字段中有java.sql.Date类型的字段的话会报错 如果是单个对象T，是没有问题的 * 如果需要将List<T>对象转换成json的话，请用objectToJsonStr()方法 *  * @param obj * @return * @throws Exception */public static <T> JSONObject objectToJson(T obj) throws Exception {if (null == obj)return new JSONObject();ObjectMapper mapper = new ObjectMapper();String jsonStr = mapper.writeValueAsString(obj);return new JSONObject(jsonStr);}/** * 将Object对象转换成JSON字符串 这种方法可以将java.sql.Date字段转换成字符串时间，如"2016-05-09" * 将java.util.Date字段转换成时间戳，如1462774004169 * 将java.sql.Timestamp字段转成成时间戳，如1462774004169 * {"utilDate":1462774004169,"sqlDate" * :"2016-05-09","timestamp":1462774004169} *  * @param <T> *  * @param obj * @return * @throws Exception */public static <T> String objectToJsonStr(T obj) throws Exception {if (null == obj)return new JSONObject().toString();StringWriter str = new StringWriter();ObjectMapper mapper = new ObjectMapper();mapper.writeValue(str, obj);return str.toString();}}

public class JsonTestMain2 {public static void main(final String[] args) throws Exception {try {TestVo vo1 = new TestVo();vo1.setSqlDate(new java.sql.Date(System.currentTimeMillis()));vo1.setUtilDate(new java.util.Date(System.currentTimeMillis()));vo1.setTimestamp(new java.sql.Timestamp(System.currentTimeMillis()));List<TestVo> list = new ArrayList<TestVo>();list.add(vo1);System.out.println(ApiJSONUtilTest.objectToJson(vo1));System.out.println(ApiJSONUtilTest.objectToJsonStr(list));System.exit(0);} catch (Exception e) {System.out.println(e);}}}

public class TestVo {private java.util.Date utilDate;private java.sql.Date sqlDate;private java.sql.Timestamp timestamp;}

输出结果如下

{"timestamp":1463710838035,"utilDate":1463710838035,"sqlDate":"2016-05-20"}[{"utilDate":1463710838035,"sqlDate":"2016-05-20","timestamp":1463710838035}]

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