java对象互换工具类

1:将Object类型转成json字符串

java 复制代码

/**
	 * 将对象转为字符串
	 * @param obj
	 * @return
	 */
	public static String toString(Object obj) {
		if(obj == null) {
			return null;
		}
		if ("".equals(obj.toString())) {
			return null;
		}
		if (obj instanceof String) {
			return obj.toString();
		}
		try {
			ObjectMapper mapper = getMapperInstance();
			StringWriter sw = new StringWriter();
			JsonGenerator gen = new JsonFactory().createGenerator(sw);
			mapper.writeValue(gen, obj);
			return sw.toString();
		} catch (IOException e) {
			LOGGER.error(e.getMessage(), e);
		}
		return null;
	}

2:将Object转成List

java 复制代码

/**
	 * 转换为List
	 * @param string
	 * @param cls		为List集合里面的类型
	 * @return
	 */
	public static <T>T toList(String string, Class<?> cls) {
		if(StringUtil.isEmpty(string)) {
			return null;
		}
		if (!string.contains("{") && !string.contains("[")) {
			return null;
		}
		try {
			ObjectMapper mapper = getMapperInstance();
			JavaType type = mapper.getTypeFactory().constructParametricType(List.class, cls);
			return mapper.readValue(string, type);
		} catch (IOException e) {
			LOGGER.error(e.getMessage());
		}
		return null;
	}

3:将字符串转为对象

java 复制代码

/**
	 * 将字符串转为对象
	 * @param string
	 * @param cls
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static <T>T toObject(String string, Class<?> cls) {
		if(StringUtil.isEmpty(string)) {
			return null;
		}
		if (!string.contains("{") && !string.contains("[")) {
			return null;
		}
		try {
			ObjectMapper mapper = getMapperInstance();
			//mapper.configure(SerializationConfig.Feature.INDENT_OUTPUT, Boolean.TRUE);
			return (T) mapper.readValue(string, cls);
		} catch (IOException e) {
			LOGGER.error(e.getMessage());
		}
		return null;
	}

4:将字符串转为JsonNode对象

java 复制代码

/**
	 * 将字符串转为JsonNode对象
	 * @param string
	 * @return
	 */
	public static JsonNode toJsonNode(String string) {
		if(StringUtil.isEmpty(string)) {
			return null;
		}
		try {
			ObjectMapper mapper = getMapperInstance();
			return mapper.readTree(string);
		} catch (IOException e) {
			LOGGER.error(e.getMessage());
		}
		return null;
	}

5:转换为List《Map》

java 复制代码

/**
	 * 转换为List<Map>
	 * @param string
	 * @return
	 */
	public static <T>T toListMap(String string) {
		if(StringUtil.isEmpty(string)) {
			return null;
		}
		if (!string.contains("{") && !string.contains("[")) {
			return null;
		}
		try {
			ObjectMapper mapper = getMapperInstance();
			JavaType type = mapper.getTypeFactory().constructType(List.class, HashMap.class);

			if (!string.startsWith(JSON_2)) {
				string = URLDecoder.decode(string, "UTF-8");
			}
			return mapper.readValue(string, type);
		} catch (IOException e) {
			LOGGER.error(e.getMessage(), e);
		}
		return null;
	}

6：将字符串转为Map对象

java 复制代码

/**
	 * 将字符串转为Map对象
	 * @param string
	 * @return 
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static <T>T toMap(String string) {
		if(StringUtil.isEmpty(string)) {
			return null;
		}
		if (!string.contains("{") && !string.contains("[")) {
			return null;
		}
		try {
			ObjectMapper mapper = getMapperInstance();
			JavaType type = mapper.getTypeFactory().constructType(Map.class);
			return (T) mapper.readValue(string, type);
		} catch (IOException e) {
			LOGGER.error(e.getMessage());
		}
		return null;
	}

类初始配置

java 复制代码

public static final String FMT_DEFAULT = "yyyy-MM-dd HH:mm:ss";
private static final Logger LOGGER = LoggerFactory.getLogger(FrameJsonUtil.class);
	//private static final String JSON_1 = "{";
	private static final String JSON_2 = "[{";
	
	private static ObjectMapper mapper;
	
	private static ObjectMapper getMapperInstance() {
		return getMapperInstance(false);
	}
	private static synchronized ObjectMapper getMapperInstance(boolean createNew) {
        if (createNew) {
        	ObjectMapper m = new ObjectMapper();
            m.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
        	return m;
        } else if (mapper == null) {
            mapper = new ObjectMapper();
        }
        mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
		SimpleDateFormat simpleDateFormat = new SimpleDateFormat(FMT_DEFAULT);
		mapper.setDateFormat(simpleDateFormat);
        return mapper;
    }

以上的是java对象互换工具类若需完整代码可识别二维码后给您发代码。