java对象互换工具类

本文主要是介绍java对象互换工具类，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1:将Object类型转成json字符串

/*** 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

/*** 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

/*** 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

/*** 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》

/*** 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

/*** 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

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;}