Hutool 中那些常用的工具类和方法

<dependency>    <groupId>cn.hutool</groupId>    <artifactId>hutool-all</artifactId>    <version>4.6.3</version></dependency>

//转换为字符串int a = 1;String aStr = Convert.toStr(a);//转换为指定类型数组String[] b = {"1", "2", "3", "4"};Integer[] bArr = Convert.toIntArray(b);//转换为日期对象String dateStr = "2017-05-06";Date date = Convert.toDate(dateStr);//转换为列表String[] strArr = {"a", "b", "c", "d"};List<String> strList = Convert.toList(String.class, strArr);

//Date、long、Calendar之间的相互转换//当前时间Date date = DateUtil.date();//Calendar转Datedate = DateUtil.date(Calendar.getInstance());//时间戳转Datedate = DateUtil.date(System.currentTimeMillis());//自动识别格式转换String dateStr = "2017-03-01";date = DateUtil.parse(dateStr);//自定义格式化转换date = DateUtil.parse(dateStr, "yyyy-MM-dd");//格式化输出日期String format = DateUtil.format(date, "yyyy-MM-dd");//获得年的部分int year = DateUtil.year(date);//获得月份，从0开始计数int month = DateUtil.month(date);//获取某天的开始、结束时间Date beginOfDay = DateUtil.beginOfDay(date);Date endOfDay = DateUtil.endOfDay(date);//计算偏移后的日期时间Date newDate = DateUtil.offset(date, DateField.DAY_OF_MONTH, 2);//计算日期时间之间的偏移量long betweenDay = DateUtil.between(date, newDate, DateUnit.DAY);

//判断是否为空字符串String str = "test";StrUtil.isEmpty(str);StrUtil.isNotEmpty(str);//去除字符串的前后缀StrUtil.removeSuffix("a.jpg", ".jpg");StrUtil.removePrefix("a.jpg", "a.");//格式化字符串String template = "这只是个占位符:{}";String str2 = StrUtil.format(template, "我是占位符");LOGGER.info("/strUtil format:{}", str2);

//获取定义在src/main/resources文件夹中的配置文件ClassPathResource resource = new ClassPathResource("generator.properties");Properties properties = new Properties();properties.load(resource.getStream());LOGGER.info("/classPath:{}", properties);

//获取某个类的所有方法Method[] methods = ReflectUtil.getMethods(PmsBrand.class);//获取某个类的指定方法Method method = ReflectUtil.getMethod(PmsBrand.class, "getId");//使用反射来创建对象PmsBrand pmsBrand = ReflectUtil.newInstance(PmsBrand.class);//反射执行对象的方法ReflectUtil.invoke(pmsBrand, "setId", 1);

double n1 = 1.234;double n2 = 1.234;double result;//对float、double、BigDecimal做加减乘除操作result = NumberUtil.add(n1, n2);result = NumberUtil.sub(n1, n2);result = NumberUtil.mul(n1, n2);result = NumberUtil.div(n1, n2);//保留两位小数BigDecimal roundNum = NumberUtil.round(n1, 2);String n3 = "1.234";//判断是否为数字、整数、浮点数NumberUtil.isNumber(n3);NumberUtil.isInteger(n3);NumberUtil.isDouble(n3);

PmsBrand brand = new PmsBrand();brand.setId(1L);brand.setName("小米");brand.setShowStatus(0);//Bean转MapMap<String, Object> map = BeanUtil.beanToMap(brand);LOGGER.info("beanUtil bean to map:{}", map);//Map转BeanPmsBrand mapBrand = BeanUtil.mapToBean(map, PmsBrand.class, false);LOGGER.info("beanUtil map to bean:{}", mapBrand);//Bean属性拷贝PmsBrand copyBrand = new PmsBrand();BeanUtil.copyProperties(brand, copyBrand);LOGGER.info("beanUtil copy properties:{}", copyBrand);

//数组转换为列表String[] array = new String[]{"a", "b", "c", "d", "e"};List<String> list = CollUtil.newArrayList(array);//join：数组转字符串时添加连接符号String joinStr = CollUtil.join(list, ",");LOGGER.info("collUtil join:{}", joinStr);//将以连接符号分隔的字符串再转换为列表List<String> splitList = StrUtil.split(joinStr, ',');LOGGER.info("collUtil split:{}", splitList);//创建新的Map、Set、ListHashMap<Object, Object> newMap = CollUtil.newHashMap();HashSet<Object> newHashSet = CollUtil.newHashSet();ArrayList<Object> newList = CollUtil.newArrayList();//判断列表是否为空CollUtil.isEmpty(list);

//将多个键值对加入到Map中Map<Object, Object> map = MapUtil.of(new String[][]{    {"key1", "value1"},    {"key2", "value2"},    {"key3", "value3"}});//判断Map是否为空MapUtil.isEmpty(map);MapUtil.isNotEmpty(map);

//获取指定类、方法、字段、构造器上的注解列表Annotation[] annotationList = AnnotationUtil.getAnnotations(HutoolController.class, false);LOGGER.info("annotationUtil annotations:{}", annotationList);//获取指定类型注解Api api = AnnotationUtil.getAnnotation(HutoolController.class, Api.class);LOGGER.info("annotationUtil api value:{}", api.description());//获取指定类型注解的值Object annotationValue = AnnotationUtil.getAnnotationValue(HutoolController.class, RequestMapping.class);

//MD5加密String str = "123456";String md5Str = SecureUtil.md5(str);LOGGER.info("secureUtil md5:{}", md5Str);

//生成验证码图片LineCaptcha lineCaptcha = CaptchaUtil.createLineCaptcha(200, 100);try {    request.getSession().setAttribute("CAPTCHA_KEY", lineCaptcha.getCode());    response.setContentType("image/png");//告诉浏览器输出内容为图片    response.setHeader("Pragma", "No-cache");//禁止浏览器缓存    response.setHeader("Cache-Control", "no-cache");    response.setDateHeader("Expire", 0);    lineCaptcha.write(response.getOutputStream());} catch (IOException e) {    e.printStackTrace();}