public static void main(String[] args) throws Exception{

        User user = new User();

        user.setUid(25);

        JsonConfig jsonConfig = new JsonConfig();

        jsonConfig.setJsonPropertyFilter(new PropertyFilter() {

            @Override

            public boolean apply(Object source, String key, Object value) {

                return false; // 返回false表示该属性会转化，true表示不转化

            }

        });

        JSONObject json = JSONObject.fromObject(user, jsonConfig );

        System.out.println(json.toString());

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

        User u1 = (User)JSONObject.toBean(json, User.class); // json转java对象，json中属性不全，一样可以转换成功

        System.out.println(u1);

    }
如果属性为空，且要转化，Integer为null的会转化为0

        <dependency>

            <groupId>net.sf.json-lib</groupId>

            <artifactId>json-lib</artifactId>

            <version>2.2.3</version>

            <classifier>jdk15</classifier>

        </dependency>