1.
官网:
https://hutool.cn/docs/#/core/工具类/正则工具-ReUtil
@Testpublic void BeanToMapTest() {Log log = new Log();log.setName("hh");log.setLastValue("lastvalue");// 用反射创建一个对象并复制属性值LogVo logVo = BeanUtil.toBean(log, LogVo.class);System.out.println(logVo);System.out.println(logVo);// 复制属性值给 beanLogVo logVoCopyProperties = new LogVo();BeanUtil.copyProperties(log,logVoCopyProperties);System.out.println(logVoCopyProperties);System.out.println(logVoCopyProperties);// 复制属性值给 mapMap<String, String> map = MapUtil.newHashMap();BeanUtil.copyProperties(log,map);System.out.println(map);}@Testpublic void CovertTest() {// Object[] a = {"a", "你", "好", "", 1};Object[] a = null ;// 将数组转集合 (需要 判断 空)//List<?> list01 = Arrays.asList(a);// 不需要 判断 null ,如果是 null 返回的 是 nullList<?> list0 = Convert.convert(List.class, a);//从4.1.11开始可以这么用 （内部有非空判断）List<?> list1 = Convert.toList(a);// 转成另一个集合类List<A> list1 = mapper.selectList(queryWrapper);List<B> applicationInfoVOList = Convert.convert(new cn.hutool.core.lang.TypeReference<List<ApplicationVO>>(){} , list1 );// 字符串 转 LocalDateTimeLocalDateTime localDateTime1 = Convert.toLocalDateTime("2020-08-14");LocalDate localDate = localDateTime1.toLocalDate();System.out.println(localDateTime1);System.out.println(localDate);}@Testpublic void MoneyTest() {// 金额大小写转换//结果为："陆万柒仟伍佰伍拾陆元叁角贰分"String digitUppercase1 = Convert.digitToChinese(BigDecimal.valueOf(67556.00d));String digitUppercase2 = Convert.digitToChinese(BigDecimal.valueOf(67556.01d));System.out.println(digitUppercase1);System.out.println(digitUppercase2);}@Testpublic void IOTest() throws IOException {FileUtil.newFile("d:/test.txt");FileUtil.newFile("d:/test2.txt");// 拷贝(u盘 ，磁盘 etc)// 将 test.txt 的内容 拷贝到 test2BufferedInputStream in = FileUtil.getInputStream("d:/test.txt");BufferedOutputStream out = FileUtil.getOutputStream("d:/test2.txt");// 最底层是个 while 循环 ，读一部分，写入到 另一个地方，此方法也不需要 进行关闭流的操作，因为已经封装了// 底层代码:// while((readSize = in.read(buffer)) != -1) {// out.write(buffer, 0, readSize);// size += (long)readSize;// out.flush();// if (null != streamProgress) {// streamProgress.progress(size);// }// }long copySize = IoUtil.copy(in, out, DEFAULT_BUFFER_SIZE);// copy(InputStream in, OutputStream out)// 用工具包// BufferedOutputStream out2 = FileUtil.getOutputStream("d:/test2.txt");// 自己 new 一个输出流对象BufferedOutputStream out2 = new BufferedOutputStream(new FileOutputStream(new File("d:/test2.txt")));IoUtil.copy(new ByteArrayInputStream("hhhhhhhhhhhhhhhhhh".getBytes()),out2,DEFAULT_BUFFER_SIZE);// 可以正常写入BufferedOutputStream out3 = new BufferedOutputStream(new FileOutputStream(new File("d:/test2.txt")));IoUtil.copy(new ByteArrayInputStream("您好a!".getBytes()),out3,DEFAULT_BUFFER_SIZE);// 汉字OutputStreamWriter out4 = new OutputStreamWriter(new FileOutputStream(new File("d:/test2.txt")),CharsetUtil.CHARSET_UTF_8);long copy = IoUtil.copy(new InputStreamReader(new ByteArrayInputStream("您好!".getBytes(CharsetUtil.CHARSET_UTF_8))), out4, DEFAULT_BUFFER_SIZE);// method// byte[] readBytes(InputStream in)// 说明：读取一个 流()// 不使用工具，自己写// ① 获取输入流ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream("您好a!".getBytes());// ② 创建缓存字节数组，用来存放 从流读取的内容 （假设这个区域很大）byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];// ③ 读取流 并将内容 放到 buffer 字节数组缓存里int read = byteArrayInputStream.read(buffer);String result = new String(buffer);System.out.println(result);System.out.println(result);// 上述方法的缺点： 如果读取的内容过大 会有数据丢失情况// 使用工具ByteArrayInputStream byteArrayInputStream3 = new ByteArrayInputStream("您好a!".getBytes());
// 底层 实现：
// byte[] buffer = new byte[bufferSize];
// if (null != streamProgress) {
// streamProgress.start();
// }
//
// long size = 0L;
//
// int readSize;
// try {
// while((readSize = in.read(buffer)) != -1) {
// out.write(buffer, 0, readSize);
// size += (long)readSize;
// out.flush();
// if (null != streamProgress) {
// streamProgress.progress(size);
// }
// }
// } catch (IOException var8) {
// throw new IORuntimeException(var8);
// }// 然后 out.toByteArray()byte[] bytes = IoUtil.readBytes(byteArrayInputStream3);String result2 = new String(bytes);System.out.println(result2);}@Testpublic void StringTest() throws IOException{String template = "{}爱{}，就像老鼠爱大米";String str = StrUtil.format(template, "我", "你"); //str -> 我爱你，就像老鼠爱大米System.out.println(str);}
对象的赋值用spring原生的：
BeanUtils.copyProperties(vo, info);一个集合转成另一个集合并赋值：
List<ApplicationInfoVersion> applicationInfoVersionsFromDb = applicationInfoVersionMapper.selectList(versionQueryWrapper);List<ApplicationInfoVersionVO> versionVOList = Convert.convert(new cn.hutool.core.lang.TypeReference<List<ApplicationInfoVersionVO>>() {}, applicationInfoVersionsFromDb);