Jackson的Json轉換

    public class JacksonJsonUtil {

        private static ObjectMapper mapper;


    /** 
     * 獲取ObjectMapper實例 
     * @param createNew 方式：true，新實例；false,存在的mapper實例 
     * @return 
     */  
    public static synchronized ObjectMapper getMapperInstance(boolean createNew) {     
        if (createNew) {     
            return new ObjectMapper();     
        } else if (mapper == null) {     
            mapper = new ObjectMapper();     
        }     
        return mapper;     
    }   

    /** 
     * 將java對象轉換成json字符串 
     * @param obj 準備轉換的對象 
     * @return json字符串 
     * @throws Exception  
     */  
    public static String beanToJson(Object obj) throws Exception {  
        try {  
            ObjectMapper objectMapper = getMapperInstance(false);  
            String json =objectMapper.writeValueAsString(obj);  
            return json;  
        } catch (Exception e) {  
            throw new Exception(e.getMessage());  
        }         
    }  

    /** 
     * 將java對象轉換成json字符串 
     * @param obj 準備轉換的對象 
     * @param createNew ObjectMapper實例方式:true，新實例;false,存在的mapper實例 
     * @return json字符串 
     * @throws Exception 
     */  
    public static String beanToJson(Object obj,Boolean createNew) throws Exception {  
        try {  
            ObjectMapper objectMapper = getMapperInstance(createNew);  
            String json =objectMapper.writeValueAsString(obj);  
            return json;  
        } catch (Exception e) {  
            throw new Exception(e.getMessage());  
        }         
    }  

    /** 
     * 將json字符串轉換成java對象 
     * @param json 準備轉換的json字符串 
     * @param cls  準備轉換的類 
     * @return  
     * @throws Exception  
     */  
    public static Object jsonToBean(String json, Class<?> cls) throws Exception {  
        try {  
        ObjectMapper objectMapper = getMapperInstance(false);  
        Object vo = objectMapper.readValue(json, cls);  
        return vo;  
        } catch (Exception e) {  
            throw new Exception(e.getMessage());  
        }     
    }  

    /** 
     * 將json字符串轉換成java對象 
     * @param json 準備轉換的json字符串 
     * @param cls  準備轉換的類 
     * @param createNew ObjectMapper實例方式:true，新實例;false,存在的mapper實例 
     * @return 
     * @throws Exception 
     */  
    public static Object jsonToBean(String json, Class<?> cls,Boolean createNew) throws Exception {  
        try {  
        ObjectMapper objectMapper = getMapperInstance(createNew);  
        Object vo = objectMapper.readValue(json, cls);  
        return vo;  
        } catch (Exception e) {  
            throw new Exception(e.getMessage());  
        }     
    }  
}  </pre><br />