// 判斷字符串是否為空或者null
boolean isEmpty = StrUtil.isEmpty(str);

// 替換字符串
String replace = StrUtil.replace(str, "old", "new");

// 正則表達(dá)式匹配
List<String> matches = ReUtil.findAll("[0-9]+", str, 0, new ArrayList<String>());

// HTML轉(zhuǎn)義
String html = EscapeUtil.escapeHtml(str);

// Emoji編碼解碼
String encode = EmojiUtil.encode("??");
String decode = EmojiUtil.decode(encode);

// 日期時(shí)間格式化
String format = DateUtil.format(new Date(), "yyyy-MM-dd HH:mm:ss");

// 日期時(shí)間計(jì)算
Date newDate = DateUtil.offset(new Date(), DateField.DAY_OF_YEAR, 1);

// 日期時(shí)間比較
boolean isSameDay = DateUtil.isSameDay(new Date(), new Date());

// Cron表達(dá)式解析
CronPattern pattern = CronUtil.parse("0 0 12 * * ?");

// 農(nóng)歷日期處理
ChineseDate chineseDate = ChineseDateUtil.parse(new Date());

// 集合判空
boolean isEmpty = CollUtil.isEmpty(list);

// 集合合并
List<String> newList = CollUtil.addAllIfNotContains(list1, list2);

// 集合截取
List<String> subList = CollUtil.sub(list, 0, 5);

// List轉(zhuǎn)數(shù)組
String[] array = ListUtil.toArray(list, String.class);

// 數(shù)組判空
boolean isEmpty = ArrayUtil.isEmpty(array);

// 數(shù)組合并
String[] newArray = ArrayUtil.addAll(array1, array2);

// 數(shù)組截取
String[] subArray = ArrayUtil.sub(array, 0, 5);

// 數(shù)字格式化
String format = NumberUtil.decimalFormat("123456.789", "#,##0.00");

// 數(shù)字轉(zhuǎn)換
Integer intValue = NumberUtil.parseInt("123");

// 數(shù)字比較
int compare = NumberUtil.compare(1, 2);

// 隨機(jī)整數(shù)
int randomInt = RandomUtil.randomInt(0, 100);

// 隨機(jī)Boolean值
boolean randomBoolean = RandomUtil.randomBoolean();

// MD5加密
String md5 = DigestUtil.md5Hex("hello world");

// SHA-256加密
String sha256 = DigestUtil.sha256Hex("hello world");

// AES加密解密
String aesKey = "aeskey1234567890";
String content = "hello world";
String encrypt = SecureUtil.aes(aesKey.getBytes(), content.getBytes(), Cipher.ENCRYPT_MODE);
String decrypt = SecureUtil.aes(aesKey.getBytes(), encrypt.getBytes(), Cipher.DECRYPT_MODE);

// RSA加密解密
KeyPair keyPair = SecureUtil.generateKeyPair("RSA");
String publicKey = Base64.encode(keyPair.getPublic().getEncoded());
String privateKey = Base64.encode(keyPair.getPrivate().getEncoded());
String rsaEncrypt = SecureUtil.rsaEncrypt(content.getBytes(), publicKey);
String rsaDecrypt = SecureUtil.rsaDecrypt(rsaEncrypt, privateKey);

// BASE64編碼解碼
String base64Encode = Base64.encode(content.getBytes());
String base64Decode = StrUtil.str(Base64.decode(base64Encode), CharsetUtil.CHARSET_UTF_8);

// 文件創(chuàng)建
File file = FileUtil.touch("D:/test.txt");

// 文件復(fù)制
FileUtil.copy("D:/test.txt", "D:/test_copy.txt", true);

// 文件刪除
FileUtil.del("D:/test.txt");

// 壓縮文件創(chuàng)建
ZipUtil.zip("D:/test.zip", "D:/test");

// 壓縮文件解壓
ZipUtil.unzip("D:/test.zip", "D:/unzip");

// 讀取Excel中的數(shù)據(jù)
ExcelReader reader = ExcelUtil.getReader("D:/test.xlsx");
List<List<Object>> readAll = reader.read();

// 讀取指定Sheet中的數(shù)據(jù)
ExcelReader sheetReader = ExcelUtil.getReader("D:/test.xlsx", "Sheet1");
List<List<Object>> readSheetAll = sheetReader.read();

// 將數(shù)據(jù)寫(xiě)入Excel中指定的Sheet中
ExcelWriter writer = ExcelUtil.getWriter("D:/test.xlsx", "Sheet1");
writer.writeCellValue(0, 0, "hello");
writer.flush();
writer.close();

// 發(fā)送GET請(qǐng)求
String result = HttpUtil.get("https://www.baidu.com");

// 發(fā)送POST請(qǐng)求
Map<String, Object> paramMap = new HashMap<>();
paramMap.put("username", "admin");
paramMap.put("password", "123456");
String postResult = HttpUtil.post("https://www.example.com/login", paramMap);

// 下載文件
FileUtil.writeBytes(HttpUtil.downloadBytes("https://www.example.com/file"), "D:/file.txt");