json-lib轉化java對象，是否轉化為null的屬性

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表示該屬性會轉化，true表示不轉化
            }
        });
        JSONObject json = JSONObject.fromObject(user, jsonConfig ); 
        System.out.println(json.toString());
        System.out.println("-----------------------------");
        User u1 = (User)JSONObject.toBean(json, User.class); // json轉java對象，json中屬性不全，一樣可以轉換成功
        System.out.println(u1);
        
    }
如果屬性為空，且要轉化，Integer為null的會轉化為0

        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.2.3</version>
            <classifier>jdk15</classifier>
        </dependency>